U.S. patent application number 14/083282 was filed with the patent office on 2014-05-22 for projection apparatus, projection method and computer-readable storage medium for correcting a projection state being projected onto curved surface.
This patent application is currently assigned to CASIO COMPUTER CO., LTD.. The applicant listed for this patent is CASIO COMPUTER CO., LTD.. Invention is credited to Tetsuro NARIKAWA.
Application Number | 20140139751 14/083282 |
Document ID | / |
Family ID | 50727600 |
Filed Date | 2014-05-22 |
United States Patent
Application |
20140139751 |
Kind Code |
A1 |
NARIKAWA; Tetsuro |
May 22, 2014 |
PROJECTION APPARATUS, PROJECTION METHOD AND COMPUTER-READABLE
STORAGE MEDIUM FOR CORRECTING A PROJECTION STATE BEING PROJECTED
ONTO CURVED SURFACE
Abstract
A chart generation unit generates an adjustment chart, and a
projection unit projects the adjustment chart onto a circular
cylinder. A parameter acquiring unit acquires 12 parameters in
total, relating to the positions of four corners and middle points
of a top side and a bottom side of a chart and lateral expansion of
the chart, the chart being input by a user through manipulations of
an operation unit. A transform function determination unit
calculates, from the total of 12 parameters, an accurate transform
function for projecting an image onto the circular cylinder. An
image conversion unit applies geometric transformation to the image
based on the calculated transform function.
Inventors: |
NARIKAWA; Tetsuro; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CASIO COMPUTER CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
CASIO COMPUTER CO., LTD.
Tokyo
JP
|
Family ID: |
50727600 |
Appl. No.: |
14/083282 |
Filed: |
November 18, 2013 |
Current U.S.
Class: |
348/789 |
Current CPC
Class: |
H04N 9/3185 20130101;
H04N 5/7475 20130101; G06T 3/60 20130101; G06T 3/005 20130101 |
Class at
Publication: |
348/789 |
International
Class: |
H04N 5/74 20060101
H04N005/74 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 19, 2012 |
JP |
2012-253624 |
Claims
1. A projection apparatus comprising: a projection unit configured
to project an image onto a target area on a curved surface formed
of generatrices of a circular cylinder; an image conversion unit
configured to apply geometric transformation to a projected image
projected by the projection unit; a parameter acquiring unit
configured to acquire a parameter expressing a positional
relationship between the projection unit and the curved surface;
and a transform function determination unit configured to determine
a transform function for use in the geometric transformation based
on the parameter, wherein the target area is an area surrounded by:
a first line and a second line which are parallel to an axis of the
circular cylinder; a third line that is an intersection line of a
first plane perpendicular to the axis with the curved surface; and
a fourth line that is an intersection line of a second plane
parallel to the first plane with the curved surface, and when an
image area is such an area that the image applied the geometric
transformation is projected onto the curved surface, the parameter
includes: a four-corner parameter to match four corners of the
image area and four corners of the target area; a first middle
point parameter to match a first middle point that is a middle
point of a top side of the image area and a middle point of the
third line of the target area; a second middle point parameter to
match a second middle point that is a middle point of a bottom side
of the image area and a middle point of the fourth line of the
target area; and a second reference line parameter to, when a line
connecting the first middle point to the second middle point of the
image area is a first reference line, adjust a position of a second
reference line provided between a left side of the image area and
the first reference line, or between a right side of the image area
and the first reference line.
2. The projection apparatus according to claim 1, wherein the
four-corner parameter includes: a first parameter and a second
parameter to match an upper left corner of the image area and an
upper left corner of the target area that is an intersection point
of the first line with the third line of the target area; a third
parameter and a fourth parameter to match a lower left corner of
the image area and a lower left corner of the target area that is
an intersection point of the first line with the fourth line of the
target area; a fifth parameter and a sixth parameter to match a
lower right corner of the image area and a lower right corner of
the target area that is an intersection point of the second line
with the fourth line of the target area; and a seventh parameter
and an eighth parameter to match an upper right corner of the image
area and an upper right corner of the target area that is an
intersection point of the second line with the third line of the
target area, the first middle point parameter and the second middle
point parameter include: a ninth parameter to, when a position in
an axial direction provided perpendicularly to the first line is
referred to as a horizontal position, match horizontal positions of
the first and second middle points and horizontal positions of the
middle point of the third line and fourth line by changing the
horizontal positions of the first middle point and the second
middle point; a tenth parameter to, when a position in an axial
direction provided parallel to the first line is referred to as
height, match a height of the first middle point and a height of
the middle point of the third line by changing the height of the
first middle point; and an eleventh parameter to match a height of
the second middle point and a height of the middle point of the
fourth line by changing the height of the second middle point, the
second reference line is a one-fourth line connecting a middle
point between the upper left corner and the first middle point to a
middle point between the lower left corner and the second middle
point and a three-fourths line connecting a middle point between
the upper right corner and the first middle point to a middle point
between the lower right corner and the second middle point, and the
second reference line parameter is a twelfth parameter to move the
one-fourth line and the three-fourths line in a direction
perpendicular to the first line.
3. The projection apparatus according to claim 1, wherein the
geometric transformation includes: rotation projection
transformation between a plane and a plane; and circular cylinder
geometric transformation between the target area and a plane
parallel to a third plane passing between the first line and the
second line.
4. The projection apparatus according to claim 3, wherein the
transform function determination unit determines the transform
function for use in the rotation projection transformation based on
the first parameter, the second parameter, the third parameter, the
fourth parameter, the fifth parameter, the sixth parameter, the
seventh parameter, and the eighth parameter, and the transform
function determination unit determines the transform function for
use in the circular cylinder geometric transformation based on the
ninth parameter, the tenth parameter, the eleventh parameter, and
the twelfth parameter.
5. The projection apparatus according to claim 2, further
comprising: a chart generation unit configured to generate an
adjustment chart expressing the upper left corner, the lower left
corner, the lower right corner, the upper right corner, the first
middle point, the second middle point, the first reference line,
and the second reference line, the adjustment chart being projected
onto the curved surface by the projection unit; and an input unit
configured to acquire moving directions of the upper left corner,
the lower left corner, the lower right corner, the upper right
corner, the first middle point, the second middle point, the first
reference line, and the second reference line input by a user,
wherein the parameter acquiring unit acquires the parameter for
each input by the user to the input unit based on the moving
direction input to the input unit, the transform function
determination unit determines the transform function for each input
by the user to the input unit based on the parameter, and the image
conversion unit applies the geometric transformation to the
adjustment chart for each input by the user to the input unit.
6. The projection apparatus according to claim 1, further
comprising a condition acquiring unit configured to acquire a
positional relationship between the projection unit and the target
area, wherein the parameter acquiring unit acquires at least one of
the parameters based on the positional relationship.
7. The projection apparatus according to claim 1, wherein the
projection unit is configured to project an image onto a rotation
target area obtained by rotating the target area about a barycenter
of the target area, the parameter acquiring unit acquires a
thirteenth parameter expressing the rotation and further included
in the parameter, and the transform function determination unit
determines the transform function for use in the geometric
transformation to project an image onto the rotation target area
based on the thirteenth parameter.
8. The projection apparatus according to claim 1, further
comprising: a transform function storage unit configured to store
the transform function determined by the transform function
determination unit; and a transform function reading unit
configured to read the transform function stored in the transform
function storage unit.
9. A projection apparatus comprising: a projection unit configured
to project an image onto a target area on a curved surface formed
of generatrices of a circular cylinder; an image conversion unit
configured to apply geometric transformation to a projected image
projected by the projection unit; a parameter acquiring unit
configured to acquire a parameter expressing a positional
relationship between the projection unit and the curved surface;
and a transform function determination unit configured to determine
a transform function for use in the geometric transformation based
on the parameter, wherein the target area is an area surrounded by:
a first line and a second line which are parallel to an axis of the
circular cylinder; a third line that is an intersection line of a
first plane perpendicular to the axis with the curved surface; and
a fourth line that is an intersection line of a second plane
parallel to the first plane with the curved surface, and the
geometric transformation includes: rotation projection
transformation between a plane and a plane; and circular cylinder
geometric transformation between the target area and a plane
parallel to a third plane passing between the first line and the
second line.
10. A projection state adjustment method comprising the steps of:
projecting an image onto a target area on a curved surface formed
of generatrices of a circular cylinder from a projection unit;
applying geometric transformation to a projected image projected
from the projection unit; acquiring a parameter expressing a
positional relationship between the projection unit and the curved
surface; and determining a transform function for use in the
geometric transformation based on the parameter, wherein the target
area is an area surrounded by: a first line and a second line which
are parallel to an axis of the circular cylinder; a third line that
is an intersection line of a first plane perpendicular to the axis
with the curved surface; and a fourth line that is an intersection
line of a second plane parallel to the first plane with the curved
surface, and when an image area is such an area that the image
applied the geometric transformation is projected onto the curved
surface, the parameter includes: a four-corner parameter to match
four corners of the image area and four corners of the target area;
a first middle point parameter to match a first middle point that
is a middle point of a top side of the image area and a middle
point of the third line of the target area; a second middle point
parameter to match a second middle point that is a middle point of
a bottom side of the image area and a middle point of the fourth
line of the target area; and a second reference line parameter to,
when a line connecting the first middle point to the second middle
point of the image area is a first reference line, adjust a
position of a second reference line provided between a left side of
the image area and the first reference line, or between a right
side of the image area and the first reference line.
11. A projection state adjustment method comprising the steps of:
projecting an image onto a target area on a curved surface formed
of generatrices of a circular cylinder from a projection unit;
applying geometric transformation to a projected image projected
from the projection unit; acquiring a parameter expressing a
positional relationship between the projection unit and the curved
surface; and determining a transform function for use in the
geometric transformation based on the parameter, wherein the target
area is an area surrounded by: a first line and a second line which
are parallel to an axis of the circular cylinder; a third line that
is an intersection line of a first plane perpendicular to the axis
with the curved surface; and a fourth line that is an intersection
line of a second plane parallel to the first plane with the curved
surface, and the geometric transformation includes: rotation
projection transformation between a plane and a plane; and circular
cylinder geometric transformation between the target area and a
plane parallel to a third plane passing between the first line and
the second line.
12. A non-transitory computer-readable storage medium storing a
projection state adjustment program that causes a computer to:
project an image onto a target area on a curved surface formed of
generatrices of a circular cylinder from a projection unit; apply
geometric transformation to a projected image projected from the
projection unit; acquire a parameter expressing a positional
relationship between the projection unit and the curved surface;
and determine a transform function for use in the geometric
transformation based on the parameter, wherein the target area is
an area surrounded by: a first line and a second line which are
parallel to an axis of the circular cylinder; a third line that is
an intersection line of a first plane perpendicular to the axis
with the curved surface; and a fourth line that is an intersection
line of a second plane parallel to the first plane with the curved
surface, and when an image area such an area that the image applied
the geometric transformation is projected onto the curved surface,
the parameter includes: a four-corner parameter to match four
corners of the image area and four corners of the target area; a
first middle point parameter to match a first middle point that is
a middle point of a top side of the image area and a middle point
of the third line of the target area; a second middle point
parameter to match a second middle point that is a middle point of
a bottom side of the image area and a middle point of the fourth
line of the target area; and a second reference line parameter to,
when a line connecting the first middle point to the second middle
point of the image area is a first reference line, adjust a
position of a second reference line provided between a left side of
the image area and the first reference line, or between a right
side of the image area and the first reference line.
13. A non-transitory computer-readable storage medium storing a
projection state adjustment program that causes a computer to:
project an image onto a target area on a curved surface formed of
generatrices of a circular cylinder from a projection unit; apply
geometric transformation to a projected image projected from the
projection unit; acquire a parameter expressing a positional
relationship between the projection unit and the curved surface;
and determine a transform function for use in the geometric
transformation based on the parameter, wherein the target area is
an area surrounded by: a first line and a second line which are
parallel to an axis of the circular cylinder; a third line that is
an intersection line of a first plane perpendicular to the axis
with the curved surface; and a fourth line that is an intersection
line of a second plane parallel to the first plane with the curved
surface, and the geometric transformation includes: rotation
projection transformation between a plane and a plane; and circular
cylinder geometric transformation between the target area and a
plane parallel to a third plane passing between the first line and
the second line.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates to a projection apparatus, a
projection state adjustment method, and a projection state
adjustment program.
[0003] 2. Related Art
[0004] Generally, a projector as an image projection apparatus is
known, in which an image based on image data output from a personal
computer, for example, is projected onto a projection target such
as a screen.
[0005] Such a projector is sometimes used to project an image onto
the curved surface of a circular cylinder, for example.
[0006] For example, in the case where an image with no distortion
is appropriately projected onto a circular cylinder, it is
necessary to apply geometric correction to a projected image.
[0007] Functions for use in such geometric correction are different
depending on the positional relationship between the projector and
the circular cylinder, such as the orientation of the projector
relative to the circular cylinder, a distance from the projector to
the circular cylinder, and the diameter of the circular
cylinder.
[0008] Thus, it is necessary to provide the settings of geometric
correction depending on the positional relationship between the
projector and the circular cylinder, for example.
[0009] Some methods are known as a setting method for such
geometric correction.
[0010] For example, a first method is a method in which a projector
is used to project a grid pattern onto a circular cylinder, and a
user adjusts the positions of intersection points of grids to
sequentially change the set values of geometric correction.
[0011] A second method is a method in which a distance and a
direction from a projector to a circular cylinder, the range of a
screen on the circular cylinder, the angle of view of the
projector, the position of an optical axis, and so on are found,
and correction values necessary for geometric correction are
calculated from the values.
[0012] For a third method, a technique is disclosed in
JP-A-2004-320662, for example, in which typical geometric
correction methods not directly involved in a circular cylinder are
combined to adjust images.
[0013] As for the foregoing setting methods for geometric
correction, according to the first method, for example, the user
can intuitively perform manipulations.
[0014] However, it is necessary to adjust a large number of
positions of intersection points, and it takes a lot of time and
effort.
[0015] For example, in the second method, it is necessary to
accurately determine the positional relationship between the
projector and the circular cylinder, for example, which is usually
difficult to determine, and it is difficult to implement the second
method.
[0016] For example, according to the third method, the user can
relatively easily perform manipulations because the amount of
manipulations is small.
[0017] However, it is difficult for the user to intuitively grasp
which geometric correction methods to combine.
[0018] Moreover, the first method and the third method provide
approximate settings, and the methods do not always provide
mathematically accurate correction.
SUMMARY
[0019] Therefore, it is an object of the present invention to
provide a projection apparatus, a projection state adjustment
method, and a projection state adjustment program that can
accurately adjust the projection of an image onto a circular
cylinder surface with easy manipulations by intuition.
[0020] In order to achieve the above object, a projection apparatus
according to an aspect of the present invention includes: [0021] a
projection unit configured to project an image onto a target area
on a curved surface formed of generatrices of a circular cylinder;
[0022] an image conversion unit configured to apply geometric
transformation to a projected image projected by the projection
unit; [0023] a parameter acquiring unit configured to acquire a
parameter expressing a positional relationship between the
projection unit and the curved surface; and [0024] a transform
function determination unit configured to determine a transform
function for use in the geometric transformation based on the
parameter, [0025] wherein the target area is an area surrounded by:
[0026] a first line and a second line which are parallel to an axis
of the circular cylinder; [0027] a third line that is an
intersection line of a first plane perpendicular to the axis with
the curved surface; and [0028] a fourth line that is an
intersection line of a second plane parallel to the first plane
with the curved surface, and [0029] when an image area is such an
area that the image applied the geometric transformation is
projected onto the curved surface, the parameter includes: [0030] a
four-corner parameter to match four corners of the image area and
four corners of the target area; [0031] a first middle point
parameter to match a first middle point that is a middle point of a
top side of the image area and a middle point of the third line of
the target area; [0032] a second middle point parameter to match a
second middle point that is a middle point of a bottom side of the
image area and a middle point of the fourth line of the target
area; and [0033] a second reference line parameter to, when a line
connecting the first middle point to the second middle point of the
image area is a first reference line, adjust a position of a second
reference line provided between a left side of the image area and
the first reference line, or between a right side of the image area
and the first reference line.
[0034] In order to achieve the above object, a projection apparatus
according to an aspect of the present invention includes: [0035] a
projection unit configured to project an image onto a target area
on a curved surface formed of generatrices of a circular cylinder;
[0036] an image conversion unit configured to apply geometric
transformation to a projected image projected by the projection
unit; [0037] a parameter acquiring unit configured to acquire a
parameter expressing a positional relationship between the
projection unit and the curved surface; and [0038] a transform
function determination unit configured to determine a transform
function for use in the geometric transformation based on the
parameter, [0039] wherein the target area is an area surrounded by:
[0040] a first line and a second line which are parallel to an axis
of the circular cylinder; [0041] a third line that is an
intersection line of a first plane perpendicular to the axis with
the curved surface; and [0042] a fourth line that is an
intersection line of a second plane parallel to the first plane
with the curved surface, and [0043] the geometric transformation
includes: [0044] rotation projection transformation between a plane
and a plane; and [0045] circular cylinder geometric transformation
between the target area and a plane parallel to a third plane
passing between the first line and the second line.
[0046] In order to achieve the above object, a projection state
adjustment method according to an aspect of the present invention
includes the steps of: [0047] projecting an image onto a target
area on a curved surface formed of generatrices of a circular
cylinder from a projection unit; [0048] applying geometric
transformation to a projected image projected from the projection
unit; [0049] acquiring a parameter expressing a positional
relationship between the projection unit and the curved surface;
and [0050] determining a transform function for use in the
geometric transformation based on the parameter, [0051] wherein the
target area is an area surrounded by: [0052] a first line and a
second line which are parallel to an axis of the circular cylinder;
[0053] a third line that is an intersection line of a first plane
perpendicular to the axis with the curved surface; and [0054] a
fourth line that is an intersection line of a second plane parallel
to the first plane with the curved surface, and [0055] when an
image area is such an area that the image applied the geometric
transformation is projected onto the curved surface, the parameter
includes: [0056] a four-corner parameter to match four corners of
the image area and four corners of the target area; [0057] a first
middle point parameter to match a first middle point that is a
middle point of a top side of the image area and a middle point of
the third line of the target area; [0058] a second middle point
parameter to match a second middle point that is a middle point of
a bottom side of the image area and a middle point of the fourth
line of the target area; and [0059] a second reference line
parameter to, when a line connecting the first middle point to the
second middle point of the image area is a first reference line,
adjust a position of a second reference line provided between a
left side of the image area and the first reference line, or
between a right side of the image area and the first reference
line.
[0060] In order to achieve the above object, a projection state
adjustment method according to an aspect of the present invention
includes the steps of: [0061] projecting an image onto a target
area on a curved surface formed of generatrices of a circular
cylinder from a projection unit; [0062] applying geometric
transformation to a projected image projected from the projection
unit; [0063] acquiring a parameter expressing a positional
relationship between the projection unit and the curved surface;
and [0064] determining a transform function for use in the
geometric transformation based on the parameter, [0065] wherein the
target area is an area surrounded by: [0066] a first line and a
second line which are parallel to an axis of the circular cylinder;
[0067] a third line that is an intersection line of a first plane
perpendicular to the axis with the curved surface; and [0068] a
fourth line that is an intersection line of a second plane parallel
to the first plane with the curved surface, and [0069] the
geometric transformation includes: [0070] rotation projection
transformation between a plane and a plane; and [0071] circular
cylinder geometric transformation between the target area and a
plane parallel to a third plane passing between the first line and
the second line.
[0072] In order to achieve the above object, a non-transitory
computer-readable storage medium according to an aspect of the
present invention stores a projection state adjustment program that
causes a computer to: [0073] project an image onto a target area on
a curved surface formed of generatrices of a circular cylinder from
a projection unit; [0074] apply geometric transformation to a
projected image projected from the projection unit; [0075] acquire
a parameter expressing a positional relationship between the
projection unit and the curved surface; and [0076] determine a
transform function for use in the geometric transformation based on
the parameter, [0077] wherein the target area is an area surrounded
by: [0078] a first line and a second line which are parallel to an
axis of the circular cylinder; [0079] a third line that is an
intersection line of a first plane perpendicular to the axis with
the curved surface; and [0080] a fourth line that is an
intersection line of a second plane parallel to the first plane
with the curved surface, and [0081] when an image area such an area
that the image applied the geometric transformation is projected
onto the curved surface, the parameter includes: [0082] a
four-corner parameter to match four corners of the image area and
four corners of the target area; [0083] a first middle point
parameter to match a first middle point that is a middle point of a
top side of the image area and a middle point of the third line of
the target area; [0084] a second middle point parameter to match a
second middle point that is a middle point of a bottom side of the
image area and a middle point of the fourth line of the target
area; and [0085] a second reference line parameter to, when a line
connecting the first middle point to the second middle point of the
image area is a first reference line, adjust a position of a second
reference line provided between a left side of the image area and
the first reference line, or between a right side of the image area
and the first reference line.
[0086] In order to achieve the above object, a non-transitory
computer-readable storage medium according to an aspect of the
present invention stores a projection state adjustment program that
causes a computer to:
[0087] project an image onto a target area on a curved surface
formed of generatrices of a circular cylinder from a projection
unit;
[0088] apply geometric transformation to a projected image
projected from the projection unit;
[0089] acquire a parameter expressing a positional relationship
between the projection unit and the curved surface; and [0090]
determine a transform function for use in the geometric
transformation based on the parameter, [0091] wherein the target
area is an area surrounded by: [0092] a first line and a second
line which are parallel to an axis of the circular cylinder; [0093]
a third line that is an intersection line of a first plane
perpendicular to the axis with the curved surface; and [0094] a
fourth line that is an intersection line of a second plane parallel
to the first plane with the curved surface, and [0095] the
geometric transformation includes: [0096] rotation projection
transformation between a plane and a plane; and [0097] circular
cylinder geometric transformation between the target area and a
plane parallel to a third plane passing between the first line and
the second line.
BRIEF DESCRIPTION OF DRAWINGS
[0098] FIG. 1 is a block diagram of an exemplary configuration of a
projector according to an embodiment of the present invention;
[0099] FIG. 2 is a diagram illustrating projection of an image onto
a circular cylinder using a projector;
[0100] FIG. 3 is a diagram illustrating the degree of freedom of
the positional relationship between the projector and the circular
cylinder;
[0101] FIG. 4 is a diagram illustrating the degree of freedom of
the positional relationship between the projector and the circular
cylinder;
[0102] FIG. 5 is a diagram illustrating the degree of freedom of
the positional relationship between the projector and the circular
cylinder;
[0103] FIG. 6 is a diagram illustrating an exemplary adjustment
chart according to an embodiment;
[0104] FIG. 7 is a diagram illustrating an exemplary adjustment
chart according to an embodiment;
[0105] FIG. 8 is a diagram illustrating an exemplary adjustment
chart according to an embodiment;
[0106] FIG. 9 is a diagram illustrating an exemplary adjustment
chart according to an embodiment;
[0107] FIG. 10 is a flowchart of an exemplary projection state
adjustment process according to an embodiment;
[0108] FIG. 11 is a flowchart of an exemplary first adjustment
chart process according to an embodiment;
[0109] FIG. 12 is a flowchart of an exemplary adjustment process
according to an embodiment;
[0110] FIG. 13 is a diagram of an exemplary projection state of an
adjustment chart onto the circular cylinder before the projection
state adjustment process;
[0111] FIG. 14 is a diagram of an exemplary projection state of an
adjustment chart onto the circular cylinder after the first
adjustment chart process;
[0112] FIG. 15 is a flowchart of an exemplary second adjustment
chart process according to an embodiment;
[0113] FIG. 16 is a diagram of an exemplary projection state of an
adjustment chart onto the circular cylinder after the second
adjustment chart process;
[0114] FIG. 17 is a flowchart of an exemplary third adjustment
chart process according to an embodiment;
[0115] FIG. 18 is a diagram of an exemplary projection state of an
adjustment chart onto the circular cylinder after the third
adjustment chart process;
[0116] FIG. 19 is a flowchart of an exemplary fourth adjustment
chart process according to an embodiment;
[0117] FIG. 20 is a diagram of an exemplary projection state of an
adjustment chart onto the circular cylinder after the fourth
adjustment chart process;
[0118] FIGS. 21A to 21D are diagrams illustrating a first
transformation and a second transformation in the projection state
adjustment process according to an embodiment;
[0119] FIG. 22 is a diagram illustrating projection of an image
onto a circular cylinder using the projector according to an
embodiment;
[0120] FIG. 23 is a diagram illustrating projection of an image
onto a circular cylinder according to an exemplary modification of
an embodiment;
[0121] FIG. 24 is a diagram illustrating projection of an image
onto a curved surface according to an exemplary modification of an
embodiment;
[0122] FIG. 25 is a diagram illustrating an adjustment chart
according to an embodiment; and
[0123] FIG. 26 is a diagram illustrating an adjustment chart
according to an embodiment.
DETAILED DESCRIPTION
[0124] An embodiment of the present invention will be described
with reference to the drawings. A projection apparatus according to
the embodiment uses a digital light processing (DLP) (registered
trademark) method using a micromirror display device.
[0125] FIG. 1 is a diagram of the schematic configuration of a
projector 1 as the projection apparatus according to the
embodiment.
[0126] The projector 1 according to the embodiment can
appropriately project an image with no distortion onto a circular
cylinder.
[0127] Thus, the projector 1 performs geometric transformation on a
projected image.
[0128] The projector 1 is configured to acquire parameters
necessary for geometric transformation from a user, as described
later.
[0129] The projector 1 includes an input/output connector unit 11,
an input/output interface (I/F) 12, an image conversion unit 13, a
projection processing unit 14, a micromirror element 15, a light
source unit 16, a mirror 18, a projection lens 20, a CPU 25, a main
memory 26, a program memory 27, an operation unit 28, a posture
sensor 29, an audio processing unit 30, a speaker 32, a projection
adjustment unit 40, and a system bus SB.
[0130] The input/output connector unit 11 is provided with a
terminal such as a pin jack (RCA) type video input terminal or a
D-sub 15 type RGB input terminal, for example, to which analog
image signals are input.
[0131] The input image signals are input to the image conversion
unit 13 through the input/output I/F 12 and the system bus SB.
[0132] The input analog image signals in various standards are
converted into digital image signals at the input/output I/F
12.
[0133] It is noted that the input/output connector unit 11 may be
configured to include an HDMI (registered trademark) terminal, for
example, and to receive digital image signals as well as analog
image signals.
[0134] Moreover, the input/output connector unit 11 receives analog
or digital audio signals.
[0135] The input audio signals are input to the audio processing
unit 30 through the input/output I/F 12 and the system bus SB.
[0136] Furthermore, the input/output connector unit 11 may be
provided with an RS232C terminal or a USB terminal, for
example.
[0137] The image conversion unit 13 is also called a scaler.
[0138] The image conversion unit 13 converts the input image data
to adjust resolution, a grayscale level, and the like and generates
image data in a predetermined format appropriate for
projection.
[0139] The image conversion unit 13 transmits the converted image
data to the projection processing unit 14.
[0140] The image conversion unit 13 transmits, to the projection
processing unit 14, image data on which symbols representing
various operating states for an on-screen display (OSD) have been
superimposed, as processed image data, when necessary.
[0141] Moreover, the image conversion unit 13 performs geometric
transformation on a projected image to project, onto a projection
target such as a screen, an image in an appropriate shape in
accordance with a projection state.
[0142] Specifically, in the embodiment, the image conversion unit
13 performs geometric transformation to appropriately project an
image onto a circular cylinder.
[0143] The light source unit 16 emits light of a plurality of
colors including the primary colors of red (R), green (G), and blue
(B).
[0144] The light source unit 16 is configured to sequentially emit
the plurality of colors divided in time.
[0145] The light emitted from the light source unit 16 is totally
reflected by the mirror 18 and enters the micromirror element
15.
[0146] The micromirror element 15 includes a plurality of
micromirrors arranged in an array.
[0147] The micromirrors operate on/off at high speeds, and reflect
the light emitted from the light source unit 16 in a direction of
the projection lens 20, or divert the light in a direction away
from the projection lens 20.
[0148] A necessary number of the micromirrors for, for example,
WXGA (Wide eXtended Graphic Array) (1280 pixels wide.times.800
pixels high) is arranged in the micromirror element 15.
[0149] With the reflection from the micromirrors, the micromirror
element 15 forms an image in, for example, the WXGA resolution.
[0150] In this manner, the micromirror element 15 functions as a
spatial optical modulator.
[0151] The projection processing unit 14 drives the micromirror
element 15 to display an image represented by the image data
transmitted from the image conversion unit 13 in accordance with
the image data.
[0152] In other words, the projection processing unit 14 operates
on/off of the micromirrors of the micromirror element 15.
[0153] The projection processing unit 14 drives the micromirror
element 15 in time division at high speeds.
[0154] The number of divisions of a unit time is obtained by
multiplying a frame rate in accordance with a predetermined format
[frames/second], the number of divided color components, and the
number of display grayscale levels.
[0155] Moreover, the projection processing unit 14 also controls
the operation of the light source unit 16 in synchronization with
the operation of the micromirror element 15.
[0156] In other words, the projection processing unit 14 divides
each frame in time, and controls the operation of the light source
unit 16 to sequentially emit the light of all the color components
in each frame.
[0157] The projection lens 20 adjusts the light guided from the
micromirror element 15 to light to be projected onto a projection
target (not illustrated) such as a screen or a circular
cylinder.
[0158] Therefore, an optical image formed by the reflected light
from the micromirror element 15 is projected and displayed on the
projection target such as a screen or a circular cylinder via the
projection lens 20.
[0159] The projection lens 20 includes a zoom mechanism and has a
function of changing the size of an image to be projected.
[0160] Moreover, the projection lens 20 includes a focus adjustment
mechanism for adjusting the focus state of a projected image.
[0161] In this manner, the projection processing unit 14, the
micromirror element 15, the light source unit 16, the projection
lens 20, and the like function as a projection unit 22 that
projects an image.
[0162] The audio processing unit 30 includes a sound generator such
as a PCM sound source.
[0163] The audio processing unit 30 drives the speaker 32 to
amplify and release sounds based on analog audio data input from
the input/output connector unit 11 or based on an analog signal
obtained by converting digital audio data given upon projection
operation.
[0164] Moreover, the audio processing unit 30 generates a beep
sound and the like when necessary.
[0165] The speaker 32 is a general speaker that emits the sound
based on the signal input from the audio processing unit 30.
[0166] The CPU 25 controls the operation of the image conversion
unit 13, the projection processing unit 14, the audio processing
unit 30, and the projection adjustment unit 40 described below.
[0167] The CPU 25 is connected to the main memory 26 and the
program memory 27.
[0168] The main memory 26 includes, for example, an SRAM.
[0169] The main memory 26 functions as working memory of the CPU
25.
[0170] The program memory 27 includes an electrically rewritable
nonvolatile memory.
[0171] The program memory 27 stores an operating program, various
fixed-format data, and the like that are executed by the CPU
25.
[0172] Moreover, the CPU 25 is connected to the operation unit
28.
[0173] The operation unit 28 includes a key operation unit provided
to a main body of the projector 1, and an infrared light receiving
unit that receives infrared light from a remote control (not
illustrated) dedicated to the projector 1.
[0174] The operation unit 28 includes an arrow key and an OK
button.
[0175] The operation unit 28 outputs, to the CPU 25, a key
operation signal based on a key operated by a user with the key
operation unit of the main body or the remote control.
[0176] The CPU 25 uses the program and data stored in the main
memory 26 and the program memory 27 to control the operation of the
units of the projector 1 in accordance with the user's instruction
from the operation unit 28.
[0177] The posture sensor 29 includes a three-axis accelerometer,
for example.
[0178] The accelerometer detects the angle of posture of the
projector 1 in the gravity direction, that is, the angles of pitch
and roll.
[0179] The posture sensor 29 outputs the detected result to the
projection adjustment unit 40.
[0180] However, the posture sensor 29 is not a necessary component,
as described later.
[0181] The projection adjustment unit 40 determines a transform
function for image geometric transformation used for appropriately
projecting an image onto a circular cylinder, for example.
[0182] The projection adjustment unit 40 includes a chart
generation unit 41, a parameter acquiring unit 42, a parameter
storage unit 43, a transform function determination unit 44, a
transform function storage unit 45, and a transform function
reading unit 46.
[0183] The chart generation unit 41 generates a projection state
adjustment chart, described later.
[0184] The adjustment chart is generated by reading a grid pattern
and markers or the like to display parameters to be presently
adjusted, for example, which are recorded on the program memory
27.
[0185] The parameter acquiring unit 42 acquires 12 conversion
parameters, described later, based on the input from the user, for
example.
[0186] The parameter storage unit 43 stores the conversion
parameters acquired by the parameter acquiring unit 42.
[0187] The transform function determination unit 44 calculates a
transform function for use in geometric transformation of an image
based on the conversion parameters acquired by the parameter
acquiring unit 42.
[0188] The transform function storage unit 45 stores the transform
function calculated by the transform function determination unit
44.
[0189] The transform function reading unit 46 reads the transform
function stored on the transform function storage unit 45, and
outputs the transform function to the image conversion unit 13, for
example.
[0190] The image conversion unit 13 performs the geometric
transformation of an image based on the transform function.
[0191] The operation of the projector 1 according to the embodiment
will be described.
[0192] Let us consider the case where the projector 1 projects an
image onto a curved surface formed of generatrices of a right
circular cylinder.
[0193] First, the relationship among the projector 1, a circular
cylinder 200, a projection area 100, and a target area 210 onto
which an image is projected, will be described with reference to
FIG. 2.
[0194] Suppose that a range in which light emitted from the
projection lens 20 of the projector 1 is projected onto a
projection target is referred to as the projection area 100.
[0195] On the surface of the circular cylinder 200, the area onto
which an image is desired to be projected is referred to as the
target area 210.
[0196] In the embodiment, the projector 1 operates to project an
image onto the circular cylinder 200 as if a sheet with a
rectangular image depicted thereon is attached to the circular
cylinder 200.
[0197] The target area 210 is the area corresponding to the sheet,
onto which an image is finally projected.
[0198] Here, a left side 212 and a right side 214 of the target
area 210 are set parallel to a center axis 202 of the circular
cylinder 200.
[0199] A top side 216 and a bottom side 218 of the target area 210
are disposed on a plane perpendicular to the center axis 202 of the
circular cylinder 200.
[0200] On the projection area 100, suppose that an area including
an image corrected by geometric transformation is referred to as an
image area 101.
[0201] That is, the projector 1 according to the embodiment
operates to match the image area 101 and the target area 210.
[0202] Here, the projector 1 performs geometric transformation to
project a desired image onto the circular cylinder 200 as if a
sheet with this image depicted thereon is attached to the circular
cylinder 200.
[0203] With this geometric transformation, a desired image is
included in the image area 101, and the image area 101 matched with
the target area 210.
[0204] First, the degree of freedom of the projection state will be
described with reference to FIGS. 3 to 5.
[0205] As depicted in FIG. 3, a coordinate system is defined as
follows, with the position of the projection lens 20 of the
projector 1 being the origin point.
[0206] That is, the projection direction of the projector 1 is
defined as a z-axis.
[0207] The right direction of the projector 1 is defined as an
x-axis, and the upper direction is defined as a y-axis on a plane
perpendicular to the z-axis when the projector 1 is oriented in the
z-axis direction.
[0208] FIG. 3 is a diagram of the positional relationship among the
projector 1, the circular cylinder 200, and the target area
210.
[0209] As described above, the left side 212 and the right side 214
of the target area 210 are parallel to each other, and the left
side 212 and the right side 214 are also parallel to the center
axis 202 of the circular cylinder 200.
[0210] Moreover, suppose that a plane passing through a top end
212-1 of the left side 212 and perpendicular to the center axis 202
of the circular cylinder 200 is a first plane 221. The first plane
221 passes through a top end 214-1 of the right side 214.
[0211] Furthermore, in the intersection line of the circular
cylinder 200 with the first plane 221, a portion sandwiched between
the left side 212 and the right side 214 is matched with the top
side 216 of the target area 210.
[0212] Suppose that a plane passing through a lower end 212-2 of
the left side 212 and perpendicular to the center axis 202 of the
circular cylinder 200 is a second plane 222. The second plane 222
passes through a lower end 214-2 of the right side 214.
[0213] In addition, in the intersection line of the circular
cylinder 200 with the second plane 222, a portion sandwiched
between the left side 212 and the right side 214 is matched with
the bottom side 218 of the target area 210.
[0214] Suppose that the intersection point of the center axis 202
of the circular cylinder 200 with the first plane 221 is a first
center O1, and the intersection point of the center axis 202 of the
circular cylinder 200 with the second plane 222 is a second center
O2.
[0215] The degree of freedom of the circular cylinder 200 relative
to the projector 1 can be expressed by six degrees of freedom in
total, i.e., coordinates O1 (x1, y1, z1) of the first center O1 and
coordinates O2 (x2, y2, z2) of the second center O2.
[0216] It is noted that since the change in a radius R of the
circular cylinder is the same as expansion or contraction of the
entire coordinate system including the projector 1 and the circular
cylinder 200, the radius R of the circular cylinder is set to one,
and is not included in the degree of freedom.
[0217] FIG. 4 is a diagram of the first plane 221.
[0218] As depicted in FIG. 4, a rotation angle to the top end 214-1
of the right side 214 from a given reference line 226 is set to
.theta.1, and a rotation angle to the top end 212-1 of the left
side 212 from the reference line 226 is set to .theta.2.
[0219] As described above, the left side 212 and the right side 214
on the circular cylinder 200 can be expressed by two degrees of
freedom.
[0220] Here, suppose that an angle expressing a portion onto which
an image expressed by (.theta.2-.theta.1) is projected is referred
to as a projection angle .theta..
[0221] FIG. 5 is a diagram of a projection range on a plane where
the z coordinate of an image that the projector 1 projects is
one.
[0222] The projection range is expressed in a rectangle, so that
the projection range can be expressed by four degrees of freedom in
total, i.e., upper left coordinates D1 (x3, y3, 1) and lower right
coordinates D2 (x4, y4, 1), for example.
[0223] As described above, in the case where an image is projected
onto the circular cylinder 200 as if a sheet with a rectangular
image depicted thereon is attached to the circular cylinder 200,
and the right and left sides of this image are adjusted to be
parallel to the center axis 202 of the circular cylinder 200, the
degree of freedom of the projection state is 12 degrees in
total.
[0224] In the projection state adjustment operation in which the
projection of an image onto the circular cylinder 200 is adjusted
as described above, the projector 1 according to the embodiment
provides the projection state adjustment operation in which the
user can intuitively adjust projection with a fewer number of
manipulations and can accurately adjust the projection state.
[0225] As described above, since the degrees of freedom of
projection onto the circular cylinder are 12 degrees, it is
necessary to acquire 12 parameters in adjusting the projection
state in order to accurately adjust the projection state.
[0226] Exemplary parameters for use in adjusting the projection
state of the projector 1 according to the embodiment and exemplary
adjustment charts for use in adjusting the projection state will be
described with reference to FIGS. 6 to 9.
[0227] Adjustment charts for use in adjusting the projection state
according to the embodiment are those as depicted in FIGS. 6 to
9.
[0228] All of these adjustment charts include the outer frame of
the image area 101 expressing an image on the projection area
100.
[0229] Moreover, for easy understanding, the adjustment charts
include grid lines provided within the outer frame.
[0230] The grid lines are provided in such a way that intervals are
provided equally on an image to be projected.
[0231] In the embodiment, adjustment markers, described later,
included in the adjustment charts are adjusted so as to be matched
with the corresponding locations on the target area 210, which is
the area onto which the image described with reference to FIG. 2 is
projected, and thus the projection state is adjusted.
[0232] FIG. 6 is a diagram of a first adjustment chart 110.
[0233] The first adjustment chart 110 includes a first corner
marker 112 expressing the upper left corner of the image area 101,
a second corner marker 114 expressing the lower left corner of the
image area 101, a third corner marker 116 expressing the lower
right corner of the image area 101, and a fourth corner marker 118
expressing the upper right corner of the image area 101.
[0234] The projector 1 performs geometric transformation on the
first adjustment chart 110 in such a way that the first corner
marker 112, the second corner marker 114, the third corner marker
116, and the fourth corner marker 118 are each moved to the top,
bottom, left, and right in response to user manipulations.
[0235] Since the first corner marker 112, the second corner marker
114, the third corner marker 116, and the fourth corner marker 118
each have two degrees of freedom, the first adjustment chart 110
has eight degrees of freedom in total.
[0236] That is, eight degrees of freedom out of the forgoing 12
degrees of freedom are defined using the first adjustment chart
110.
[0237] FIG. 7 is a diagram of a second adjustment chart 120.
[0238] The second adjustment chart 120 includes a median marker 122
expressing a line connecting the middle point of the projected
image on the top side of the image area 101 to the middle point of
the projected image on the bottom side of the image area 101.
[0239] The projector 1 performs geometric transformation on the
second adjustment chart 120 in such a way that the median marker
122 is moved to the left and right in response to user
manipulations.
[0240] Since the median marker 122 has one degree of freedom, the
second adjustment chart 120 has one degree of freedom.
[0241] That is, one degree of freedom out of the foregoing 12
degrees of freedom is defined using the second adjustment chart
120.
[0242] FIG. 8 is a diagram of a third adjustment chart 130.
[0243] The third adjustment chart 130 includes a top side marker
132 expressing the middle point of the projected image on the top
side of the image area 101 and a bottom side marker 134 expressing
the middle point of the projected image on the bottom side of the
image area 101.
[0244] The projector 1 performs geometric transformation on the
third adjustment chart 130 in such a way that the top side marker
132 and the bottom side marker 134 are moved vertically in response
to user manipulations.
[0245] Since the top side marker 132 and the bottom side marker 134
each have one degree of freedom, the third adjustment chart 130 has
two degrees of freedom in total.
[0246] That is, two degrees of freedom out of the foregoing 12
degrees of freedom are defined using the third adjustment chart
130.
[0247] FIG. 9 is a diagram of a fourth adjustment chart 140.
[0248] The fourth adjustment chart 140 includes a one-fourth line
marker 142 that is a line between the left side of the image area
and the median indicated by the foregoing median marker 122, and a
three-fourths line marker 144 that is a line between the right side
of the image area and the foregoing median.
[0249] The projector 1 performs geometric transformation on the
fourth adjustment chart 140 in such a way that the one-fourth line
marker 142 and the three-fourths line marker 144 are moved to the
left and right in response to user manipulations.
[0250] Here, the one-fourth line marker 142 and the three-fourths
line marker 144 are configured to move symmetrically (to change the
width) with the foregoing median being the center axis.
[0251] That is, since the one-fourth line marker 142 and the
three-fourths line marker 144 have one degree of freedom, the
fourth adjustment chart 140 has one degree of freedom.
[0252] That is, one degree of freedom out of the foregoing 12
degrees of freedom is defined using the fourth adjustment chart
140.
[0253] As described above, in the embodiment, the first adjustment
chart 110, the second adjustment chart 120, the third adjustment
chart 130, and the fourth adjustment chart 140 define the 12
degrees of freedom.
[0254] As a result, the projector 1 can calculate a transform
function for geometric transformation necessary to accurately match
the image area 101 and the target area 210 using parameters input
with the adjustment charts.
[0255] As described above, for example, the median marker 122
functions as a first reference line.
[0256] For example, the one-fourth line marker 142 and the
three-fourths line marker 144 function as second reference
lines.
[0257] Next, a projection state adjustment process in the projector
1 according to the embodiment will be described with reference to a
flowchart depicted in FIG. 10.
[0258] The projection state adjustment process is started by a
user's instruction when the projector 1 is oriented toward the
circular cylinder 200, for example.
[0259] In Step S101, the projection adjustment unit 40 performs a
first adjustment chart process of adjusting the positions of four
corners of the image area.
[0260] The first adjustment chart process will be described with
reference to a flowchart depicted in FIG. 11.
[0261] In Step S201, the projection adjustment unit 40 projects the
first adjustment chart 110.
[0262] That is, the projection adjustment unit 40 generates the
first adjustment chart 110, and causes the projection processing
unit 14 to project the first adjustment chart 110.
[0263] In Step S202, the projection adjustment unit 40 highlights
the first corner marker 112 at the upper left on the first
adjustment chart 110.
[0264] That is, the projection adjustment unit 40 generates the
first adjustment chart 110 on which the first corner marker 112 is
highlighted more than the other corner markers by changing the
color or size of the first corner marker 112, for example, and
outputs the first adjustment chart 110 to the image conversion unit
13.
[0265] The image conversion unit 13 applies image conversion to the
first adjustment chart 110, and outputs the converted first
adjustment chart 110 to the projection processing unit 14.
[0266] The projection processing unit 14 projects the first
adjustment chart 110, which has undergone the image conversion and
has been input from the image conversion unit 13.
[0267] In Step S203, the projection adjustment unit 40 performs an
adjustment process on the first corner marker 112.
[0268] The adjustment process will be described with reference to
FIG. 12.
[0269] In Step S301, the projection adjustment unit 40 projects the
adjustment chart.
[0270] In the adjustment process on the first corner marker 112,
the projection adjustment unit 40 projects the first adjustment
chart 110 on which the first corner marker 112 is highlighted.
[0271] In the projection, the user performs adjustment
manipulations using the arrow key, for example.
[0272] For example, in the adjustment process on the first corner
marker 112, the user inputs an instruction to move the first corner
marker 112 to the top, bottom, left, and right using the arrow key
in such a way that the position of the first corner marker 112 is
matched with the top end 212-1 of the left side 212 of the target
area 210.
[0273] In Step S302, the projection adjustment unit 40 determines
whether the user has performed adjustment manipulations.
[0274] When the projection adjustment unit 40 determines that
adjustment manipulations have been made, the process goes to Step
S303.
[0275] In Step S303, the projection adjustment unit 40 causes the
image conversion unit 13 to apply image conversion.
[0276] In the image conversion, the projection adjustment unit 40
determines conversion parameters based on user adjustment
manipulations, and calculates a transform function for geometric
transformation on the projected image based on the conversion
parameters.
[0277] The projection adjustment unit 40 outputs the calculated
transform function to the image conversion unit 13.
[0278] The image conversion unit 13 performs arithmetic operations
on geometric transformation for the projected image based on the
transform function acquired from the projection adjustment unit
40.
[0279] After that, the process returns to Step S301.
[0280] For example, in the adjustment process on the first corner
marker 112, the projection adjustment unit 40 determines conversion
parameters for moving the projection position of the first corner
marker 112 in the direction corresponding to the pressed arrow
key.
[0281] The projection adjustment unit 40 calculates a transform
function to deform the first adjustment chart 110 based on the
present transform function and the determined conversion
parameters.
[0282] The user manipulates the arrow key in such a way that the
position of the first corner marker 112 is matched with the top end
212-1 of the left side 212 of the target area 210 while seeing the
first adjustment chart 110 projected onto the circular cylinder
200.
[0283] The projection adjustment unit 40 outputs the calculated
transform function to the image conversion unit 13.
[0284] The image conversion unit 13 performs arithmetic operations
on geometric transformation for the first adjustment chart 110
based on the transform function acquired from the projection
adjustment unit 40.
[0285] In Step S301, the first adjustment chart 110 subjected to
geometric transformation is projected.
[0286] In Step S302, when the projection adjustment unit 40
determines that adjustment manipulations have not been made, the
process goes to Step S304.
[0287] In Step S304, the projection adjustment unit 40 determines
whether the user has input OK indicating the completion of the
adjustment process.
[0288] When the projection adjustment unit 40 determines that the
user has not input OK, the process returns to Step S301, and the
present projection is maintained.
[0289] On the other hand, when the projection adjustment unit 40
determines that the user has input OK, the process goes to Step
S305.
[0290] For example, in the adjustment process on the first corner
marker 112, when the position of the first corner marker 112 is
matched with the top end 212-1 of the left side 212 of the target
area 210, the user presses the OK button.
[0291] As described above, the conversion parameters on geometric
transformation for the adjustment chart are sequentially acquired
in response to user adjustment manipulations until the user presses
the OK button, and a transform function is calculated from the
conversion parameters.
[0292] Moreover, geometric transformation is applied to the
adjustment chart using the calculated transform function, and the
adjustment chart subjected to the geometric transformation is
projected.
[0293] In Step S305, the projection adjustment unit 40 stores the
conversion parameters on the geometric transformation process in
the previous Step S303 in the parameter storage unit 43, and
records the transform function in the transform function storage
unit 45.
[0294] After the recording, the adjustment process is ended, and
the process returns to the first adjustment chart process.
[0295] Referring again to FIG. 11, the description is continued on
the first adjustment chart process.
[0296] After the adjustment process in Step S203, the process goes
to Step S204.
[0297] In Step S204, the projection adjustment unit 40 ends
highlighting the first corner marker 112, and highlights the second
corner marker 114 at the lower left.
[0298] That is, the projection adjustment unit 40 generates the
first adjustment chart 110 on which the second corner marker 114 is
highlighted, and outputs the first adjustment chart 110 to the
projection processing unit 14 through the image conversion unit 13
for projecting the first adjustment chart 110.
[0299] In Step S205, the projection adjustment unit 40 performs an
adjustment process on the second corner marker 114.
[0300] The adjustment process is similar to the case of the first
corner marker 112.
[0301] That is, the user manipulates the arrow key in such a way
that the second corner marker 114 is matched with the lower end
212-2 of the left side 212 of the target area 210.
[0302] The projection adjustment unit 40 calculates a transform
function for geometric transformation to deform the first
adjustment chart 110 in such a way that the projection position of
the second corner marker 114 is moved to the top, bottom, left, and
right in response to pressing of the arrow key.
[0303] The image conversion unit 13 performs geometric
transformation on the first adjustment chart 110 based on the
calculated transform function.
[0304] When the position of the second corner marker 114 is matched
with the lower end 212-2 of the left side 212 of the target area
210, the user presses the OK button.
[0305] The conversion parameters and the transform function at this
time are recorded, and then the adjustment process is ended.
[0306] In Step S206, the projection adjustment unit 40 ends
highlighting the second corner marker 114, and highlights the third
corner marker 116 at the lower right.
[0307] In Step S207, the projection adjustment unit 40 performs an
adjustment process on the third corner marker 116.
[0308] The adjustment process is similar to the case of the first
corner marker 112.
[0309] That is, the user manipulates the arrow key in such a way
that the third corner marker 116 is matched with the lower end
214-2 of the right side 214 of the target area 210.
[0310] The projection adjustment unit 40 calculates a transform
function for geometric transformation to deform the first
adjustment chart 110 in such a way that the projection position of
the third corner marker 116 is moved to the top, bottom, left, and
right in response to pressing of the arrow key.
[0311] The image conversion unit 13 performs geometric
transformation on the first adjustment chart 110 based on the
calculated transform function.
[0312] When the position of the third corner marker 116 is matched
with the lower end 214-2 of the right side 214 of the target area
210, the user presses the OK button.
[0313] The conversion parameters and the transform function at this
time are recorded, and then the adjustment process is ended.
[0314] In Step S208, the projection adjustment unit 40 ends
highlighting the third corner marker 116, and highlights the fourth
corner marker 118 at the upper right.
[0315] In Step S209, the projection adjustment unit 40 performs an
adjustment process on the fourth corner marker 118.
[0316] The adjustment process is similar to the case of the first
corner marker 112.
[0317] That is, the user manipulates the arrow key in such a way
that the fourth corner marker 118 is matched with the top end 214-1
of the right side 214 of the target area 210.
[0318] The projection adjustment unit 40 calculates a transform
function for geometric transformation to deform the first
adjustment chart 110 in such a way that the projection position of
the fourth corner marker 118 is moved to the top, bottom, left, and
right in response to pressing of the arrow key.
[0319] The image conversion unit 13 performs geometric
transformation on the first adjustment chart 110 based on the
calculated transform function.
[0320] When the position of the fourth corner marker 118 is matched
with the top end 214-1 of the right side 214 of the target area
210, the user presses the OK button.
[0321] The conversion parameters and the transform function at this
time are recorded, and then the adjustment process is ended.
[0322] As described above, the first adjustment chart process is
ended, and the process returns to the projection state adjustment
process.
[0323] For example, suppose that the first adjustment chart 110 is
first projected as depicted in FIG. 13.
[0324] Here, on the chart depicted in FIG. 13, for simplicity, the
number of grids within the outer frame is half the number of grids
on the chart depicted in FIG. 6 vertically and horizontally.
[0325] Moreover, the markers are not displayed on the chart.
[0326] In FIG. 13, broken lines indicate the target area 210.
[0327] These also apply in FIGS. 14, 16, 18, and 20 below.
[0328] According to the first adjustment chart process described
above, the first adjustment chart 110 projected as depicted in FIG.
13 is turned into the state in which the positions of four corners
are matched with the positions of four corners of the target area
210 as depicted in FIG. 14.
[0329] Referring again to FIG. 10, the description is
continued.
[0330] After the first adjustment chart process, in Step S102, the
projection adjustment unit 40 performs a second adjustment chart
process.
[0331] An exemplary second adjustment chart process will be
described with reference to FIG. 15.
[0332] Although the second adjustment chart process is different in
the adjustment chart and the markers for use, the second adjustment
chart process is basically similar to the first adjustment chart
process.
[0333] In Step S401, the projection adjustment unit 40 projects the
second adjustment chart 120 including the median marker 122.
[0334] In Step S402, the projection adjustment unit 40 performs an
adjustment process on the median marker 122.
[0335] The user manipulates the left and right keys of the arrow
key in such a way that the median marker 122 is positioned in the
middle between the left side 212 and the right side 214 of the
target area 210.
[0336] The projection adjustment unit 40 calculates a transform
function for geometric transformation to deform the second
adjustment chart 120 in such a way that the projection position of
the median marker 122 is moved to the left and right in response to
pressing of the left and right keys.
[0337] The image conversion unit 13 performs geometric
transformation on the second adjustment chart 120 based on the
calculated transform function.
[0338] When the position of the median marker 122 is positioned in
the middle between the left side 212 and the right side 214, the
user presses the OK button.
[0339] The conversion parameters and the transform function at this
time are recorded, and then the adjustment process is ended.
[0340] For example, according to the second adjustment chart
process, the adjustment chart projected as depicted in FIG. 14 is
turned as depicted in FIG. 16.
[0341] That is, the center in the lateral direction of the second
adjustment chart 120, which is the projected image, is matched with
the center of the target area 210 in the lateral direction.
[0342] Referring again to FIG. 10, the description is
continued.
[0343] After the second adjustment chart process, in Step S103, the
projection adjustment unit 40 performs a third adjustment chart
process.
[0344] An exemplary third adjustment chart process will be
described with reference to FIG. 17.
[0345] Although the third adjustment chart process is different in
the adjustment chart and the markers for use, the third adjustment
chart process is basically similar to the first adjustment chart
process.
[0346] In Step S501, the projection adjustment unit 40 projects the
third adjustment chart 130.
[0347] In Step S502, the projection adjustment unit 40 highlights
the top side marker 132 on the third adjustment chart 130.
[0348] In Step S503, the projection adjustment unit 40 performs an
adjustment process on the top side marker 132.
[0349] The user manipulates the up and down keys of the arrow key
in such a way that the top side marker 132 is at the same height as
the middle point of the top side 216 of the target area 210, that
is, the top side marker 132 is matched with the middle point of the
top side 216.
[0350] The projection adjustment unit 40 calculates a transform
function for geometric transformation to deform the third
adjustment chart 130 in such a way that the projection position of
the top side marker 132 is moved vertically in response to pressing
of the up and down keys.
[0351] The image conversion unit 13 performs geometric
transformation on the third adjustment chart 130 based on the
calculated transform function.
[0352] When the position of the top side marker 132 is at the same
height as the middle point of the top side 216 of the target area
210, the user presses the OK button.
[0353] The conversion parameters and the transform function at this
time are recorded, and then the adjustment process is ended.
[0354] In Step S504, the projection adjustment unit 40 highlights
the bottom side marker 134 on the third adjustment chart 130.
[0355] In Step S505, the projection adjustment unit 40 performs an
adjustment process on the bottom side marker 134.
[0356] The user manipulates the up and down keys of the arrow key
in such a way that the bottom side marker 134 is at the same height
as the bottom side 218 of the target area 210, that is, the bottom
side marker 134 is matched with the middle point of the bottom side
218.
[0357] The projection adjustment unit 40 calculates a transform
function for geometric transformation to deform the third
adjustment chart 130 in such a way that the projection position of
the bottom side marker 134 is moved vertically in response to
pressing of the up and down keys.
[0358] The image conversion unit 13 performs geometric
transformation on the third adjustment chart 130 based on the
calculated transform function.
[0359] When the position of the bottom side marker 134 is at the
same height as the middle point of the bottom side 218 of the
target area 210, the user presses the OK button.
[0360] The conversion parameters and the transform function at this
time are recorded, and then the adjustment process is ended.
[0361] As described above, the third adjustment chart process is
ended, and the process returns to the projection state adjustment
process.
[0362] For example, according to the third adjustment chart
process, the adjustment chart projected as in FIG. 16 is turned as
depicted in FIG. 18.
[0363] It is noted that the order of performing the second
adjustment chart process and the third adjustment chart process can
be changed.
[0364] Moreover, the user may finely adjust the adjustment chart
while repeating the second adjustment chart process and the third
adjustment chart process.
[0365] Adjustment using the second adjustment chart process and the
third adjustment chart process is performed to match four corners
of the target area 210 and four corners of the image area 101,
which are on the outer frame of the adjustment chart.
[0366] Additionally, the middle point (the top side marker 132) of
the top side of the image area 101 is matched with the middle point
of the top side 216 of the target area 210, and the middle point
(the bottom side marker 134) of the bottom side of the image area
101 is matched with the middle point of the bottom side 218 of the
target area 210.
[0367] It is noted that in some cases, the top side of the image
area 101 is not completely matched with the top side 216 of the
target area 210 and the bottom side of the image area 101 is not
completely matched with the bottom side 218 of the target area 210
even though the second adjustment chart process and the third
adjustment chart process are performed.
[0368] Referring again to FIG. 10, the description is
continued.
[0369] After the third adjustment chart process, in Step S104, the
projection adjustment unit 40 performs a fourth adjustment chart
process.
[0370] An exemplary fourth adjustment chart process will be
described with reference to FIG. 19.
[0371] Although the fourth adjustment chart process is different in
the adjustment chart and the markers for use, the fourth adjustment
chart process is basically similar to the first adjustment chart
process.
[0372] In Step S601, the projection adjustment unit 40 projects the
fourth adjustment chart 140 including the one-fourth line marker
142 and the three-fourths line marker 144.
[0373] In Step S602, the projection adjustment unit 40 performs an
adjustment process on the one-fourth line marker 142 and the
three-fourths line marker 144.
[0374] The user manipulates the left and right keys of the arrow
key in such a way that the one-fourth line marker 142 is positioned
in the middle between the left side 212 of the target area 210 and
the median adjusted in the third adjustment chart process and the
three-fourths line marker 144 is positioned in the middle between
the right side 214 of the target area 210 and the median.
[0375] The projection adjustment unit 40 calculates a transform
function for geometric transformation to deform the fourth
adjustment chart 140 in such a way that the projection positions of
the one-fourth line marker 142 and the three-fourths line marker
144 are moved to the left and right in response to pressing of the
left and right keys.
[0376] The image conversion unit 13 performs geometric
transformation on the fourth adjustment chart 140 based on the
calculated transform function.
[0377] Here, the one-fourth line marker 142 and the three-fourths
line marker 144 are moved together symmetrically with respect to
the median.
[0378] When the positions of the one-fourth line marker 142 and the
three-fourths line marker 144 are at desired positions, the user
presses the OK button.
[0379] The conversion parameters and the transform function at this
time are recorded, and then the adjustment process is ended.
[0380] For example, according to the foregoing fourth adjustment
chart process, the adjustment chart projected as in FIG. 18 is
turned as depicted in FIG. 20.
[0381] That is, the image area 101, which is the outer frame of the
fourth adjustment chart 140 and the projected image, is completely
matched with the outer frame of the target area 210, and images to
be projected at even intervals, for example, in the image area are
projected at even intervals.
[0382] That is, the images are projected as if a sheet with a
rectangular image depicted thereon is attached to the circular
cylinder.
[0383] Referring again to FIG. 10, the description is
continued.
[0384] After the fourth adjustment chart process, in Step S105, the
projection adjustment unit 40 outputs a transform function finally
calculated based on 12 conversion parameters obtained as a result
of the first to fourth adjustment chart processes.
[0385] The transform function is used for geometric transformation
at the image conversion unit 13 in image projection until the
transform function is canceled.
[0386] The transform function is stored in the transform function
storage unit 45 in association with the adjustment date and the
setting name.
[0387] As described above, the projection state adjustment process
is ended.
[0388] The transform function recorded in the transform function
storage unit 45 is read by the transform function reading unit 46
any time and output to the image conversion unit 13 for use in
image conversion at the image conversion unit 13.
[0389] Therefore, for example, the positional relationship between
the projector 1 frequently used and the circular cylinder 200 is
adjusted once for the projection state. When the transform function
is once found, the projection state adjustment process may not be
performed for second time and later.
[0390] At this time, the transform function reading unit 46 reads
the transform function stored in the transform function storage
unit 45, and the projector 1 can immediately project images
correctly onto a desired area.
[0391] Next, geometric transformation performed in the adjustment
process will be described with reference to FIGS. 21A to 21D.
[0392] It can be considered that geometric transformation performed
in the embodiment is divided into two image conversion
processes.
[0393] As depicted in FIG. 21A, let us consider geometric
transformation in the case where the projector 1 projects an image
onto the target area 210 on the circular cylinder 200.
[0394] As indicated by a two-dot chain line in FIG. 21A, suppose
that a plane passing through the right side and the left side of
the target area 210 is referred to as a cut plane 250.
[0395] Moreover, suppose that a plane perpendicular to the
projection direction of the projector 1 is referred to as a
projection plane 170.
[0396] Generally, as depicted in FIG. 21A, the cut plane 250 and
the projection plane 170 are not parallel to each other.
[0397] On the other hand, as depicted in FIG. 21B, in the case
where the cut plane 250 and the projection plane 170 are parallel
to each other, geometric transformation from the projection plane
170 to the target area 210 is relatively easily performed.
[0398] Therefore, in the embodiment, in the case where the cut
plane 250 and the projection plane 170 are not parallel to each
other, let us consider an intermediate plane 180 parallel to the
cut plane 250, as depicted in FIG. 21C.
[0399] Geometric transformation from the intermediate plane 180 to
the target area 210 is a first transformation.
[0400] For example, suppose that four variables for the center (Ox,
Oy, Oz) of the circular cylinder 200 and the projection angle
.theta. expressing the width of the target area are variables
expressing the circular cylinder 200. The variables can be
determined from the move parameter of the median marker 122 in the
lateral direction, the move parameter of the top side marker 132 in
the vertical direction, the move parameter of the bottom side
marker 134 in the vertical direction, and a half value of the value
of the projection angle .theta. expressing the width of the target
area indicated by the one-fourth line marker 142 and the
three-fourths line marker 144.
[0401] Moreover, as depicted in FIG. 21D, conversion from the
projection plane 170 to the intermediate plane 180 is a second
transformation.
[0402] This second transformation is rotation projection
transformation from a plane to a plane generally known.
[0403] The transformation formula of the rotation projection
transformation can be determined from the coordinates of four
corners of the image area 101 determined using the first adjustment
chart 110.
[0404] In the embodiment, geometric transformation from the
projection plane 170 to the target area 210 as depicted in FIG. 22
is performed by two transformations, i.e., the first transformation
and the second transformation described above.
[0405] Here, the parameters of the first transformation can be
obtained by the second adjustment chart process using the second
adjustment chart 120, the third adjustment chart process using the
third adjustment chart 130, and the fourth adjustment chart process
using the fourth adjustment chart 140.
[0406] Furthermore, the parameters of the second transformation can
be obtained by the first adjustment chart process using the first
adjustment chart 110.
[0407] As described above, for example, the cut plane 250
corresponds to a third plane, and the first transformation
corresponds to circular cylinder geometric transformation between
the target area and the plane parallel to the third plane.
[0408] According to the projection state adjustment process of the
embodiment, 12 variables can be found by mathematically completely
solving the 12 variables based on inputs made by adjustment
manipulations using the first to fourth adjustment charts, so that
the transformation formula of accurate geometric transformation
necessary for projection can be determined.
[0409] Moreover, 12 parameters input to solve the 12 variables
include the positions of four corners of the image area 101, the
positions of the top side and the bottom side in the vertical
direction, the position of the median in the lateral direction, and
the interval between the one-fourth line and the three-fourths
line.
[0410] These parameters can be grasped by the user much more
intuitively than the case where the user directly inputs the
positional relationship between the projector 1 and the circular
cylinder 200, the projection angle .theta. expressing the target
area, and so on, for example.
[0411] Therefore, according to the embodiment, the user can
intuitively perform manipulations in adjusting the projection
state.
[0412] Moreover, the fact that the adjustment chart is updated in
real time in response to the user input also facilitates
manipulates by intuition.
[0413] Furthermore, since it is only necessary to input a minimum
necessary amount of parameters, i.e., the 12 parameters, the number
of manipulations for adjustment is small for the user.
[0414] According to the embodiment, therefore, the user can
intuitively, easily, and accurately adjust the projection
state.
[0415] In addition, geometric transformation is determined in such
a way that the transformation process is separated into the first
transformation and the second transformation as in the embodiment,
so that the amount of arithmetic operations is reduced.
[0416] This is effective for high-speed processing. In the
embodiment, the combination of the first adjustment chart 110
corresponding to the first transformation and the second adjustment
chart 120, the third adjustment chart 130, and the fourth
adjustment chart 140 corresponding to the second transformation is
used to easily separate geometric transformation into the first
transformation and the second transformation.
[0417] It is noted that in the embodiment, for example, the first
to fourth adjustment chart processes are performed sequentially.
However, the first to fourth adjustment chart processes may be
appropriately returned or skipped depending on the user's
instruction.
[0418] Moreover, the order of procedures in each process, such as
the first adjustment chart process, can be similarly changed.
[0419] In the embodiment, the description has been made in which
the user inputs all of unknown 12 parameters.
[0420] However, the projection adjustment unit 40 can acquire
values related to a part of parameters even though the user does
not always input these parameters.
[0421] For example, the projection adjustment unit 40 can acquire
the angle of view of the projection lens 20 from a sensor provided
on the projection lens 20 or from a control unit controlling the
projection lens 20.
[0422] Furthermore, the projection adjustment unit 40 can acquire
the posture of the projector 1, for example, from the foregoing
posture sensor 29.
[0423] The projection adjustment unit 40 may acquire the diameter
of the circular cylinder 200 input to the operation unit 28 by the
user or acquire the positional relationship between the optical
axis of the projector 1 and the circular cylinder 200.
[0424] Even though some of the 12 parameters are not input, all the
12 degrees of freedom are calculated and an accurate transform
function can be acquired, as long as the values of the parameters
are acquired.
[0425] That is, user manipulations necessary for adjustment can be
reduced.
[0426] As described above, for example, the portion where the angle
of view of the projection lens 20 is acquired and the posture
sensor 29 function as a condition acquiring unit to acquire the
positional relationship between the projection unit and the target
area, but the portion and the posture sensor 29 are not necessarily
included in the configuration.
[0427] For example, arithmetic operations for bilaterally
symmetrical parameters can be reduced in the conversion parameters
acquired using the first to fourth adjustment charts, as long as it
is apparent that the projector 1 is disposed directly opposite to
the circular cylinder 200.
[0428] In this case, for example, the corner markers on the first
adjustment chart may be moved in bilateral symmetry, and adjustment
to be made by the third adjustment chart becomes unnecessary.
[0429] Moreover, adjustment to be made by the fourth adjustment
chart becomes unnecessary as long as the projection angle .theta.
is apparent.
[0430] In the embodiment, an example has been described in which an
image is projected onto the right circular cylinder. However, the
case where an image is projected onto an oblique circular cylinder
is also similar to the description above, as long as the left and
right sides of the target area are parallel to the axis of the
oblique circular cylinder.
[0431] Furthermore, in the embodiment, the conditions are given
that the right and left sides of the target area 210 are parallel
to the axis of the circular cylinder 200. However, for example, as
depicted in FIG. 23, the target area 210 may be rotated with
respect to the axis of the circular cylinder.
[0432] In this case, there are 13 conversion parameters.
[0433] In this case, for example, a chart can be used, as a fifth
adjustment chart, to adjust this rotation angle.
[0434] Although the number of conversion parameters is increased, a
variety of projection is made possible.
[0435] In addition, in the embodiment, an example has been
described in which an image is projected onto the protruding curved
surface of a circular cylinder.
[0436] However, as depicted in FIG. 24, also the case where an
image is projected onto a recessed curved surface 300 forming a
part of a circumferential surface can be operated similarly to the
foregoing embodiment, not limited to the protruding curved
surface.
[0437] In the projection, it is not necessary to change the
settings of the projector 1.
[0438] That is, the user can adjust the projection state by
completely the same manipulates without regard to whether the
cylinder is circular or recessed.
[0439] Moreover, in the embodiment, an example has been shown in
which an image is projected onto a curved surface. However, the
projection adjustment unit 40 can also be used for adjusting the
projection state in the case where an image is projected onto a
plane (which corresponds to a circular cylinder surface with an
infinite radius).
[0440] In this case, the first adjustment chart process alone may
be performed in which the first adjustment chart 110 is used to
match four corners of the image area and four corners of the target
area, and it is not necessary to perform the second to fourth
adjustment chart processes.
[0441] That is, the second transformation alone may be performed
between the foregoing first transformation and second
transformation.
[0442] In adjustment using the adjustment chart, a position guide
mark may be displayed near the center of the adjustment chart in
such a way that the user can clearly recognize which point the user
is currently adjusting or the user can recognize the direction of a
peripheral part of the adjustment chart even in the case where the
peripheral part is out of the circular cylinder and not
projected.
[0443] For example, as depicted in FIG. 25, when the first corner
marker 112 on the first adjustment chart 110 is being adjusted, the
first adjustment chart 110 may include the position guide mark 113
near the center of the first adjustment chart 110.
[0444] Similarly, for example, as depicted in FIG. 26, when the top
side marker 132 on the third adjustment chart 130 is being
adjusted, the third adjustment chart 130 may include a position
guide mark 133 near the center of the third adjustment chart
130.
[0445] Moreover, intervals to update the values of the parameters
by user manipulations may be linearly changed in response to the
number of pressing the arrow key or the time to press the arrow
key, for example, or may be changed in a different way.
[0446] For example, intervals can be changed for a shorter time or
a longer time according to parameter values or user's
instructions.
[0447] The present invention is not limited to the embodiments as
they are, and can be embodied in the implementation stage by
deforming the components within a range that does not depart from
its spirit.
[0448] Moreover, various embodiments of the invention can be formed
by an appropriate combination of a plurality of the components
disclosed in the embodiments.
[0449] For example, even if some components are deleted from all
the components illustrated in the embodiments, if the problem
stated in the related art, the problem being attempted to be solved
by the embodiments of the invention, can be solved and, if the
effects of the embodiments of the invention can be obtained, the
configuration where the components have been deleted can be
extracted as an embodiment of the invention.
[0450] Furthermore, the components over the different embodiments
may be combined as appropriate.
* * * * *