U.S. patent application number 10/320661 was filed with the patent office on 2003-07-03 for electronic camera for producing quickview images.
This patent application is currently assigned to NIKON CORPORATION. Invention is credited to Kuroiwa, Toshihisa.
Application Number | 20030122952 10/320661 |
Document ID | / |
Family ID | 19189667 |
Filed Date | 2003-07-03 |
United States Patent
Application |
20030122952 |
Kind Code |
A1 |
Kuroiwa, Toshihisa |
July 3, 2003 |
Electronic camera for producing quickview images
Abstract
An electronic camera according to the present invention
includes: an image pickup part for picking up a subject image to
produce image data; a processing part for processing the image data
outputted from the image pickup part to produce a quickview image
for monitor display and also produce image data for record on a
recording medium; and a monitor part for displaying the quickview
image. The processing part commences displaying the quickview image
on the monitor part prior to the production of the image data for
record. This processing allows the display of the quickview image
to be commenced without waiting for completion of the production of
the image data for record. Therefore, it is possible to shorten the
time lag occurring at displaying the quickview image, thereby
improving the convenience of the electronic camera.
Inventors: |
Kuroiwa, Toshihisa;
(Miura-shi, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
NIKON CORPORATION
Tokyo
JP
|
Family ID: |
19189667 |
Appl. No.: |
10/320661 |
Filed: |
December 17, 2002 |
Current U.S.
Class: |
348/333.11 ;
348/222.1; 348/305; 348/333.05; 348/E5.047 |
Current CPC
Class: |
H04N 9/04551 20180801;
H04N 5/23293 20130101; H04N 1/2112 20130101; H04N 2101/00 20130101;
H04N 2201/0084 20130101; H04N 1/2137 20130101 |
Class at
Publication: |
348/333.11 ;
348/305; 348/222.1; 348/333.05 |
International
Class: |
H04N 005/222; H04N
005/228 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 2001 |
JP |
2001-400744 |
Claims
What is claimed is:
1. An electronic camera comprising: an image pickup part for
picking up a subject image to produce image data; a processing part
for processing said image data outputted from said image pickup
part to produce a quickview image and image data for record, the
quickview image being used for monitor display, the image data for
record being to be recorded on a recording medium; and a monitor
part for displaying said quickview image, wherein said processing
part commences displaying said quickview image on said monitor part
prior to a completion of production of said image data for
record.
2. The electronic camera according to claim 1, wherein said
processing part comprises: an image processing part for receiving
said image data outputted from said image pickup part to
image-process said image data and produce said image data for
record; and a quickview producing part for receiving said image
data outputted from said image pickup part to reduce the number of
pixels of said image data and to thereby produce said quickview
image, and for commencing displaying said quickview image on said
monitor part prior to the completion of production of said image
data for record.
3. The electronic camera according to claim 1, wherein said
processing part comprises: a buffer part for temporarily storing
said image data outputted from said image pickup part; a reducing
part for receiving said image data from one of said image pickup
part and said buffer part to reduce the number of pixels of said
image data and to thereby produce slimmed-down intermediate data;
and an image processing part for producing said quickview image
first by image-processing said intermediate data outputted from
said reducing part and for producing said image data for record
second by image-processing said image data temporarily stored in
said buffer part.
4. The electronic camera according to claim 1, further comprising:
an image compressing part for compressing said quickview image
first and said image data for record second to produce their
respective compressed data; and a recording part for recording the
compressed data of said quickview image first and the compressed
data of said produced image data for record second.
5. The electronic camera according to claim 3, wherein when said
image pickup part produces a plurality of sets of image data by
continuously picking up a subject image, said buffer part
sequentially and temporarily stores said plurality of sets of image
data outputted from said image pickup part, said image processing
part reads said image data temporarily stored in said buffer part
and produces said image data for record, and said reducing part
reduces the number of pixels of said image data for record to
produce said quickview images in sequence.
6. The electronic camera according to claim 5, further comprising
an image compressing part for compressing said quickview image and
said image data for record, wherein when said image pickup part
produces the plurality of sets of image data by continuously
picking up the subject image, said buffer part temporarily stores
said quickview images sequentially produced by said reducing part,
and said image compressing part receives said quickview images from
said buffer part to compress said quickview images.
7. The electronic camera according to claim 5, further comprising:
an image compressing part for sequentially compressing said image
data for record to produce compressed data thereof; and a recording
part for recording the compressed data of image data for record
sequentially produced by said image compressing part, wherein when
said image pickup part produces a plurality of sets of image data
by continuously picking up a subject image, said buffer part
temporarily stores the compressed data of said image data for
record sequentially produced by said image compressing part, and
said recording part receives the compressed data of said image data
for record from said buffer part and records the received
compressed data of said image data for record.
8. The electronic camera according to claim 1, wherein said
processing part reduces the number of pixels of said quickview
image to produce a thumbnail image for a display list.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The disclosure of the following priority application is
herein incorporated by reference: Japanese Patent Application
No.2001-400744, filed Dec. 28, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electronic camera that
internally processes image data obtained by picking up subject
images. More particularly, the present invention relates to an
electronic camera that produces image data for record to be
recorded on a recording medium and quickview images for monitor
display.
[0004] 2. Description of the Related Art
[0005] In conventional electronic cameras, the following procedures
are performed to process image data.
[0006] 1) Image Capture
[0007] An electronic camera reads image data from its internal
image sensor. The electronic camera implements signal processings
on the image data, such as A/D conversion, defective pixel
correction, optical black-level correction, gain adjustment, white
balance adjustment, tone correction and so on. The signal-processed
image data are stored in a buffer memory within the electronic
camera.
[0008] 2) Image Processing
[0009] The electronic camera implements image processings on the
signal-processed image data, such as color interpolation, color
coordinate transformation, color correction, special frequency
filtering and so on, and thereby produce image data for record.
[0010] 3) Production of Quickview
[0011] The electronic camera reduces the image size of the image
data for record to produce a quickview image.
[0012] 4) Production and Compression of Thumbnail
[0013] The electronic camera reduces the image size of the image
data for record to generate a thumbnail image for a display list.
The electronic camera compresses the thumbnail image by use of a
hardware or software processing.
[0014] 5) Image Compression
[0015] The electronic camera image-compresses the image data for
record by use of a hardware processing or the like.
[0016] 6) Recording
[0017] The electronic camera implements file recording of the
image-compressed resultants on a recording medium.
[0018] The inventor of the present invention recognizes the
following problems existent in the above-described processings.
[0019] (1) First Problem
[0020] In general, a user or operator of the electronic camera
displays a quickview image on its monitor screen after capturing a
subject image. He or she may use this quickview image on the
photo-taking spot to determine whether the captured result is good
or not. It is preferable that the user or operator can check the
quickview without delay at the time of photographing. It is,
therefore, desirable that the quickview image be produced as soon
as possible after the capturing of the subject image.
[0021] In the foregoing example of the prior art, however, the
image size of the image data for record has to be reduced for
generation of the quickview image. In such a case, quick generation
of the quickview image is difficult because there is a need for
waiting for a completion of generation of the image data for
record.
[0022] For the generation of image data for record, in general, it
is necessary to process full-sized image data. Additionally, in
order to improve the picture quality of the electronic camera,
those image processings have to be high-level, complicated
processings. This tends to elongate the time taken for the
processings on the image data for record, and the generation of the
quickview image delays accordingly.
[0023] For the reason above, the above-described example of the
prior art is disadvantageous in terms of availability that a time
lag is likely to occur from photographing to displaying the
quickview image, so that the user cannot check the captured image
smoothly.
[0024] (2) Second Problem
[0025] Reusing the quickview image during image reproduction can
shorten the time required for the image reproduction on the
monitor. To prepare for such reuse during image reproduction, it is
necessary, when the image data for record is recorded, to record
the quickview image together with the image data for record.
[0026] In the above-described example of the prior art, the
electronic camera must additionally compress and recode the
quickview image after completing the image compression of preceding
image data for record. This elongates the time required for
photographing by a time needed for performing the additional
processings accordingly. Consequently, disadvantages such as a
reduction in the speed of a continuous shooting are likely to
arise.
SUMMARY OF THE INVENTION
[0027] In view of solving the above-described problems, it is an
object of the present invention to decrease the time lag in
displaying the quickview image.
[0028] The present invention will be now described below.
[0029] (1) An electronic camera according to the present invention
includes: an image pickup part for picking up a subject image to
produce image data; a processing part for processing the image data
outputted from the image pickup part to produce a quickview image
and image data for record, the quickview image being used for
monitor display, the image data for record being to be recorded on
a recording medium; and a monitor part for displaying the quickview
image. The processing part commences displaying the quickview image
on the monitor part before the production of the image data for
record is completed.
[0030] In this processing, the display of the quickview image is
commenced before the image data for record is generated. Thus, the
quickview image can be quickly displayed without waiting for the
completion of production of the image data for record. As a result,
the time lag occurring at displaying the quickview image can be
reduced, so that the user can review the captured image
significantly smoothly.
[0031] (2) More preferably, the processing part of the electronic
camera according to the present invention includes an image
processing part and a quickview producing part. Upon receiving the
image data outputted from the image pickup part, the image
processing part image-processes the image data to produce the image
data for record. On the other hand, the quickview producing part,
upon receiving the image data outputted from the image pickup part,
reduces the number of the pixels of the image data to produce the
quickview image, and then commences the display of the quickview
image before the image data for record is produced.
[0032] In this processing, the quickview image is produced from the
output of the image pickup part. In such a case, the production
processing of the quickview image is almost irreverent of the image
processing of the image data for record. This lessens the time loss
occurring due to the processings on the image data for record,
thereby enabling quick production of the quickview image. As a
result, the time lag occurring at displaying the quickview image
can be reduced, so that the user can check the captured image
significantly smoothly.
[0033] (3) Also preferably, the processing part of the electronic
camera according to the present invention includes a buffer part, a
reducing part and an image processing part. The buffer part
temporarily stores the image data outputted from the image pickup
part. Upon receiving the image data from the image pickup part or
the buffer part, the reducing part reduces the number of the pixels
of the image data to produce slimmed-down intermediate data (which
will be referred to simply as "intermediate data" hereinafter). The
image processing part firstly image-processes the intermediate data
to produce the quickview image and thereafter image-processes the
image data temporarily stored in the buffer part to produce the
image data for record.
[0034] The slimmed-down intermediate data are produced first in
this processing. Next, the image processing part preferentially
image-processes the intermediate data, thereby producing the
quickview image. The intermediate image can be produced at a high
speed because it is produced by a relatively simple processing such
as reducing the pixel number. Moreover, the production of the
quickview image from the intermediate image can be completed at a
high speed because the number of the pixels of the intermediate
image to be processed is small. As a result, the time lag occurring
at displaying the quickview image can be decreased, so that the
user can review the captured image significantly smoothly.
[0035] Furthermore, since the reducing part produces the
intermediate image, the number of the pixels which the image
processing part processes for production of the quickview image is
small, resulting in substantially lessening the amount of the
processings by the image processing part. As a result, the image
processing part has a margin to perform other processings in
addition to the production processing of the quickview image. This
margin of the image processing part is efficiently utilized. By
utilizing this margin, the image processing part produces the image
data for record after producing the quickview image. This
eliminates the need to provide any independent image processing
parts dedicated to the quickview images and to the image data for
record, thereby simplifying the structure of the electronic
camera.
[0036] (4) More preferably, the electronic camera according to the
present invention further includes an image compressing part and a
recording part. The image compressing part first image-compresses
the quickview image and the image data for record next to produce
their respective compressed data. The recording part first records
the compressed data of the quickview image and the compressed data
of the image data for record next.
[0037] According to the processings described above, the quickview
image and image data for record are compressed and recorded in the
same order which is the quickview image first, the image data for
record second. In such a case, it is possible to complete the
compression and recording of a preceding quickview image to some
extent before the commencement of outputting the image data for
record, which can further shortens the total processing time.
[0038] (5) Also preferably, the electronic camera according to the
present invention changes the processings on the image data in the
following manner when the image pickup part continuously picks up
the subject image to produce a plurality of sets of image data.
That is, the buffer part temporarily stores the plurality of sets
of image data in order in which the sets of image data are
outputted from the image pickup part. The image processing part
reads the image data temporarily stored in the buffer part and
produces image data for record. Then, the reducing part reduces the
number of the pixels of the image data for record to produce
quickview images.
[0039] According to the processings described above, in order to
perform the continuous shooting, each set of image data for record
is produced with priority to a respective quickview image. Each
quickview image is produced by reducing the number of the pixels of
a respective set of image data for record. In such a case, every
time a set of image data for record is produced, the buffer part
can release the corresponding memory space. This increases the
usage efficiency of the buffer part, by which further increases the
number of the frames to be continuously shot at one time. In
addition, the memory capacity required for the buffer part may be
reduced.
[0040] In the above case, each quickview image is produced later
than its respective set of image data for record. During the
continuous shooting, however, the user scarcely checks the
quickview images so that the delay in producing the quickview
images causes no significant problems.
[0041] It should be noted that in order to perform the continuous
shooting, the production of the quickview images may be omitted, or
the quickview images may be compressed or recorded after the
continuous shooting. In such a case, it is possible to shorten the
time required to process the image data of each frame, which makes
it easier to increase the speed of the continuous shooting.
[0042] (6) More preferably, the electronic camera according to the
present invention further includes an image compressing part for
image-compressing the quickview images and the image data for
record. When the image pickup part continuously picks up the
subject image to produce the plurality of sets of image data, the
electronic camera implements the processings as follows. That is,
the buffer part temporarily stores the quickview images which are
sequentially produced by the reducing part. The image compressing
part receives the quickview images from the buffer part to
image-compress the quickview images.
[0043] According to the processings described above, the quickview
images, which are sequentially generated by the continuous
shooting, are temporarily stored in the buffer part. The image
compressing part receives the quickview images from the buffer part
to implement image compression thereon. Therefore, in a case where
the image compressing part alone performs most of data processings
such as in the continuous shooting mode, the quickview images may
be compressed at appropriate times (by utilizing, for example, free
times of the image compressing part).
[0044] The quickview images are relatively small in content, and
hence occupy small regions of the buffer part. The regions of the
buffer part are less occupied when compression is performed at
appropriate times than when a processing sequence where image data
for record are stored in the buffer is performed. This results in
easily securing extraneous regions of the buffer part for the
buffering in the continuous shooting mode, and in increasing the
possible number of frames to be continuously shot.
[0045] (7) Also preferably, the electronic camera according to the
present invention includes an image compressing part for
image-compressing the image data for record to produce compressed
data thereof and a recording part for recording the compressed data
of the image data for record. When the image pickup part
continuously picks up the subject image to produce a plurality of
sets of image data, the electronic camera implements processings as
follows. That is, the buffer part temporarily stores the compressed
data of the image data for record which are successively produced
by the image compressing part. The recording part receives the
compressed data of the image data for record from the buffer part
and records them.
[0046] According to the processings described above, during the
continuous shooting, the compressed data of the image data for
record are temporarily stored in the buffer part. Upon receiving
the compressed data of the image data for record from the buffer
part, the recording part records them. Therefore, in a case where
the image compressing part alone performs most of data processings
such as in the continuous shooting mode, the quickview images may
be compressed at appropriate times (by utilizing, for example, free
times of the recording part).
[0047] The regions of the buffer part are less occupied when
compression is performed at appropriate times than when a
processing sequence where not-yet-compressed image data for record
are stored in the buffer is performed. This results in easily
securing extraneous regions of the buffer part for the buffering in
the continuous shooting mode, and in increasing the possible number
of frames to be continuously shot.
[0048] (8) More preferably, the foregoing processing part of the
electronic camera according to the present invention further
reduces the number of the pixels of the quickview image to produce
a thumbnail image for a display list.
[0049] According to the processing described above, the pixels of
the quickview image are reduced in number to produce the thumbnail
image for the display list. In such a case, processing slimmed-down
quickview images realizes quick creation of so that the thumbnail
image.
[0050] It is particularly preferable that the image compression of
the thumbnail image be performed by using image compressing means
that is different from the image compressing part (for example, by
software compression using an internal microprocessor or the like).
This allows the image compression of the thumbnail image to be
implemented without interfering with the image compressions of the
image data for record and of the quickview image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] The nature, principle, and utility of the invention will
become more apparent from the following detailed description when
read in conjunction with the accompanying drawings in which like
parts are designated by identical reference numbers, in which:
[0052] FIG. 1 is a block diagram showing the structure of an
electronic camera 1 according to a first embodiment of the present
invention.
[0053] FIG. 2 is a timing chart showing operations of the
electronic camera 1.
[0054] FIG. 3 is a block diagram showing the structure of an
electronic camera 11 according to a second embodiment of the
present invention.
[0055] FIG. 4 is a diagram showing signal processing paths of the
electronic camera 11 in a single shooting mode.
[0056] FIG. 5 is a timing chart of the electronic camera 11 in the
single shooting mode.
[0057] FIG. 6 is a diagram showing signal processing paths of the
electronic camera 11 in a continuous shooting mode.
[0058] FIG. 7 is a timing chart of the electronic camera 11 in the
continuous shooting mode.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0059] Embodiments of the present invention will be described below
with reference to the drawings.
[0060] <FIRST EMBODIMENT>
[0061] FIG. 1 is a block diagram showing the structure of an
electronic camera 1 according to a first embodiment of the present
invention. The structure of the electronic camera 1 will be
described below with reference to FIG. 1.
[0062] The electronic camera 1 has lenses 2 mounted thereon, and
also has an image sensor 3 whose image plane is located in the
image space of the lenses 2. An output of the image sensor 3 is
supplied through an A/D converting part 4 to a signal processing
part 5, an output of which is supplied to an image processing part
6 and also supplied to a quickview producing part 7.
[0063] The image processing part 6 implements image processings on
the output supplied from the signal processing part 5 to produce
image data for record, which are then supplied to an image
compressing part 8.
[0064] On the other hand, the quickview producing part 7 produces a
quickview image based on the output supplied from the signal
processing part 5. The quickview image is supplied to the image
compressing part 8, and also supplied to a monitor display part 7a
and displayed thereon for monitoring. The quickview producing part
7 also produces a thumbnail image that is small in image size. The
thumbnail image is outputted to a thumbnail compressing part 9.
[0065] The image compressing part 8 image-compresses the quickview
image first and image data for record next to output their
respective compressed data to a recording part 10. Meanwhile, the
thumbnail compressing part 9 implements image compression of the
thumbnail image to output the compressed data thereof to the
recording part 10. The recording part 10 records these compressed
data onto a recording medium such as a memory card or the like.
[0066] [Relation between the Invention and the Present
Embodiment]
[0067] The relations between the invention and the present
embodiment will be described below. It, however, should be noted
that such correspondence is intended to show an example of
interpretation just for reference sake and is not intended to limit
the present invention.
[0068] The image pickup part recited in the Claims corresponds to
the image sensor 3, A/D converting part 4 and signal processing
part 5.
[0069] The processing part recited in the Claims corresponds to the
image processing part 6 and quickview producing part 7.
[0070] The monitor part recited in the Claims corresponds to the
monitor display part 7a.
[0071] The image processing part recited in the Claims corresponds
to the image processing part 6.
[0072] The quickview producing part recited in the Claims
corresponds to the quickview producing part 7.
[0073] The image compressing part recited in the Claims corresponds
to the image compressing part 8.
[0074] The recording part recited in the Claims corresponds to the
recording part 10.
[0075] [Explanation of Operations of the First Embodiment]
[0076] FIG. 2 is a timing chart showing operations of the
electronic camera 1.
[0077] The operations of the electronic camera 1 will be explained
below with reference to FIG. 2.
[0078] (1) Exposure
[0079] The lenses 2 focus a subject image onto the image plane of
the image sensor 3. The image plane of the image sensor 3 includes
a color filter array of a Bayer pattern or the like, which provides
optical color separation of the subject image. The image sensor 3
implements photoelectric conversion of the thus separated color
components (RGB or the like) pixel by pixel, and stores them as
signal charges.
[0080] (2) Scan/Read
[0081] The image sensor 3 stores the signal charges for a
predetermined exposure time period under a known electronic shutter
control or with a mechanical shutter. Thereafter, the image sensor
3 outputs an image signal in accordance with a driving pulse
supplied from a timing generator (not shown). The A/D converting
part 4 A/D converts the image signal in real time to output digital
image data.
[0082] (3) Signal Processing
[0083] The digital converted image data are inputted to the signal
processing part 5, which executes processings on the image data in
real time, such as defective pixel correction, optical black-level
correction, gain correction, white balance correction, gamma
correction and so on.
[0084] (4) Production of Image Data for Record
[0085] The image processing part 6 sequentially receives the
real-time-processed image data from the signal processing part 5,
and implements image processings on the image data, such as color
interpolation processing, color correction processing, filter
processing and so on, thereby producing image data for record. The
image data for record are temporarily stored in an image memory
(not shown) within the image processing part 6.
[0086] (5) Production of quickview Image and Production of
Thumbnail Image
[0087] The quickview producing part 7 sequentially receives the
real-time-processed image data from the signal processing part 5.
The quickview producing part 7 equally partitions the pixel pattern
of the image data in accordance with the numbers of the vertical
and horizontal pixels of a quickview image to be produced, thereby
providing pixel blocks that are equal in number to the pixels of
the quickview image. The quickview producing part 7 averages each
sort of color components in each of the pixel blocks to provide the
signal components of the quickview image. The monitor display part
7a displays the quickview image for monitoring. A user or operator
can quickly review the last picked-up or captured image by viewing
this monitor display.
[0088] It should be appreciated that a quickview image may be
produced by thinning out the image data.
[0089] The quickview producing part 7 thins out the pixels of the
produced quickview image, thereby further reducing the image size
to produce a thumbnail image for a display list.
[0090] The productions of the quickview and thumbnail images
described above are simple in operation and deal with small amounts
of data as compared with the foregoing production of the image data
for record. Therefore, the quickview and thumbnail images are
generated earlier than the image data for record. Consequently, the
earlier generated quickview image is outputted prior to the image
data for record.
[0091] It should be noted that the foregoing "Production of
quickview Image" and "Production of Thumbnail Image" are preferably
implemented in a pipeline fashion.
[0092] (6) Thumbnail Compression
[0093] The thumbnail compressing part 9 receives the thumbnail
image from the quickview producing part 7 and implements image
compression thereof. The small compressed data are temporality held
within the thumbnail compressing part 9 and outputted to the
recording part 10 at a time when the recording part 10 is ready for
recording.
[0094] (7) quickview Compression
[0095] The image compressing part 8 receives the quickview image
from the quickview producing part 7 and implements image
compression thereof.
[0096] (8) Recording of quickview Compressed Data
[0097] The recording part 10 receives the compressed data of the
quickview image from the image compressing part 8 and sequentially
records them.
[0098] (9) Compression of Image Data for Record
[0099] The image compressing part 8 receives, after completing the
image compression of the quickview image, the image data for record
from the image processing part 6, and implements image compression
thereof.
[0100] (10) Recording of Compressed Data of Thumbnail Images
[0101] The recording part 10 receives, after completing the
recording of the compressed data of the quickview images, the
compressed data of the thumbnail images from the thumbnail
compressing part 9, and records them in sequence.
[0102] (11) Recording of Compressed Data of Image Data for
Record
[0103] The recording part 10 receives, after completing the
recording of the compressed data of the thumbnail image, the
compressed data of the image data for record from the image
compressing part 8, and sequentially records them.
[0104] The series of operations explained above completes the
imaging procedure of the electronic camera 1.
[0105] [Advantages of the First Embodiment]
[0106] As described above, in the first embodiment, the outputting
of the quickview image is commenced prior to that of the image data
for record. Therefore, the quickview image can be quickly
displayed, so that the user can review the captured image quite
smoothly.
[0107] Particularly, in the first embodiment, the quickview
producing part 7 directly receives the image data from the signal
processing part 5 to produce the quickview image. This allows the
production of the quickview image to be commenced quickly without
waiting for a completion of the time-consuming processings
implemented by the image processing part 6. As a result, the time
lag occurring at displaying the quickview image can be
significantly reduced.
[0108] Besides, in the first embodiment, the production of the
quickview image and that of the image data for record are performed
in parallel. In this case, it is advantageous that the production
of the image data for record does not delay since the production of
the image data for record starts nearly at the same time as that of
the quickview image.
[0109] Additionally, in the first embodiment, the outputting of the
quickview image and that of the image data for record are commenced
in the order named. The image compressing part 8 implements image
compressions on them in this order. This allows the image
compression of the quickview image to advance to some degree in
parallel with the production of the image data for record, so that
the whole processing time can be efficiently shortened.
[0110] Furthermore, in the first embodiment, the compressed data of
the quickview image and that of the image data for record are
produced in the order named. The recording part 10 implements the
recordings of the compressed data in this order. This allows the
recording of the compressed data of the quickview image to advance
to some degree in parallel with the production of the image data
for record, so that the whole processing time can be efficiently
shortened.
[0111] Also, in the first embodiment, the quickview image is
processed to produce the thumbnail image. In this case, only the
slimmed-down quickview image needs to be processed, which enables
quick production of the thumbnail image through a simple
processing.
[0112] Next, another embodiment will be described below.
[0113] <Second Embodiment>
[0114] FIG. 3 is a block diagram showing the structure of an
electronic camera 11 according to a second embodiment. FIG. 3 shows
a control IC 99 surrounded with dashed lines. The signal processing
system of the electronic camera 11 is constituted of the control IC
99 and peripheral components.
[0115] The structure of the electronic camera 11 will be described
below in detail.
[0116] The electronic camera 11 has a lens 12 mounted thereon, and
also has an image sensor 13 whose image plane is located in the
image space of the lens 12. Image data outputted from the image
sensor 13 are supplied to an A/D converting part 14 to be
digitalized thereby. The digitalized image data are then inputted
to a signal processing engine 99a.
[0117] The signal processing engine 99a is constituted of
processing blocks a signal processing part 15, a thinning part 16,
an image processing part 17, a resolution converting part 18, an
image compressing part 19 and so on. These processing blocks 15
through 19 are connected with one another via direct signal paths
and via a picture bus 20.
[0118] A video controller 31, a video encoder 32 and so on are also
connected to the picture bus 20 via a FIFO 30. A video signal
outputted from the video encoder 32 is displayed on a liquid
crystal monitor 32a provided on the back surface of the electronic
camera 11.
[0119] The picture bus 20 is also connected to a system bus 24 and
to an external bus 25 via bus interfaces 21 and 22 that switch bus
connections. These bus interfaces 21 and 22 are controlled by a
microprocessor 50 that will be described later.
[0120] The external bus 25 is connected to external components: a
SDRAM (synchronous DRAM) 26, a ROM 27, an I/O device 28 and so on.
In order to produce a control signal for the SDRAM 26, an SDRAM
controller 26a is provided in the control IC 99. In order to
realize a DMA (direct memory access) transfer without intervention
of the microprocessor 50 that will be described later, a DMA
controller 26b is also provided in the control IC 99.
[0121] On the other hand, the system bus 24 is connected to a
serial port 41, a USB (Universal Serial Bus) 42 and a card
interface 43. Port terminals of the serial port 41 are extended to
the exterior to the control IC 99 and connected to an audio LSI 45,
a timing generator 44 that drives the image sensor 13, and so on. A
terminal of the USB 42 is also extended to the exterior to the
control IC 99 and may be connected to an external host computer 46
if necessary. The card interface 43 writes data into a memory card
47 for data storage.
[0122] The control IC 99 also incorporates the microprocessor 50
for system control. The microprocessor 50 is constituted of a data
cache 51, a RISC (Reduced Instruction Set Computer) core 52 that is
an instruction executing unit, and an instruction cache 53.
[0123] [Correspondence between the Invention and the Present
Embodiment]
[0124] The correspondence between the invention and the present
embodiment will be described below. It, however, should be noted
that such correspondence is intended to show an example of
interpretation just for reference sake and is not intended to limit
the present invention.
[0125] The image pickup part recited in the Claims corresponds to
the image sensor 13, A/D converting part 14 and signal processing
part 15.
[0126] The processing part recited in the Claims corresponds to the
thinning part 16, image processing part 17, resolution converting
part 18, image compressing part 19, video controller 31 and
microprocessor 50.
[0127] The monitor part recited in the Claims corresponds to the
liquid crystal monitor 32a.
[0128] The buffer part recited in the Claims corresponds to the
SDRAM 26.
[0129] The reducing part recited in the Claims corresponds to the
thinning part 16 and resolution converting part 18.
[0130] The image processing part recited in the Claims corresponds
to the image processing part 17.
[0131] The image compressing part recited in the Claims corresponds
to the image compressing part 19.
[0132] The recording part recited in the Claims corresponds to the
card interface 43 and microprocessor 50.
[0133] [Explanation of Operation of Single Shooting]
[0134] The electronic camera 11 described above has two shooting
modes: a single shooting mode and a continuous shooting mode. An
operation of the single shooting mode will be explained below
first.
[0135] FIG. 4 is a diagram showing signal processing paths of the
electronic camera 11 in the single shooting mode.
[0136] FIG. 5 is a timing chart of the electronic camera 11 in the
single shooting mode.
[0137] The operation of the single shooting mode will be now
explained below with reference to FIGS. 3 through 5.
[0138] (1) Exposure
[0139] The image plane of the image sensor 13 includes a color
filter array of a Bayer pattern or the like. The image sensor 13
performs, pixel by pixel, photoelectric conversion on
color-separated lights through the color filter array, and stores
them as signal charges.
[0140] (2) Scan/Read
[0141] The image sensor 13 stores the signal charges for a
predetermined exposure time period, and thereafter outputs an image
signal in accordance with a driving pulse supplied from the timing
generator 44. The A/D converting part 14 A/D converts the image
signal in real time to output digital image data.
[0142] (3) Signal Processing
[0143] The digital-converted image data are inputted to the signal
processing part 15, which performing processings on those image
data-in real time, such as defective pixel correction, optical
black-level (OB) correction, gain adjustment, white balance (WB)
adjustment, gamma correction and so on.
[0144] (4) Buffer Storage
[0145] The image data outputted in real time from the signal
processing part 15 are supplied to the thinning part 16, while they
are temporarily stored in the SDRAM 26 via the picture bus 20 and
external bus 25.
[0146] (5) Reduction
[0147] The thinning part 16 sequentially receives image data
outputted in real time by the signal processing part 15. The
thinning part 16 implements pixel number reduction (pixel thinning,
pixel averaging or the like) on the image data to produce
intermediate data in which the pixels have been reduced in
number.
[0148] In the view of performing consistent processing, it is
preferable that the intermediate data be subjected to a color
interpolation equivalent to the color interpolation of image data
for record that will be described later. Therefore, the thinning
part 16 of the present embodiment implements pixel number reduction
such that the color pattern of the image data and that of the
intermediate data will coincide with each other.
[0149] In a case where the image sensor 13 is of interlace system,
the image data of the first field are temporarily stored in the
SDRAM 26, and subsequently the image data of the second field are
outputted from the signal processing part 15. At this moment, the
thinning part 16 preferably implements pixel number reduction each
time a predetermined unit of data becomes available for the pixel
number reduction.
[0150] (6) Image Processing of Intermediate Data
[0151] The image processing part 17 sequentially receives the
intermediate data from the thinning part 16. The image processing
part 17 sequentially implements the color interpolation processing,
color correction processing and filter processing on the
intermediate data.
[0152] (7) Resolution Adjustment of quickview Image and Production
of Thumbnail Image
[0153] The resolution converting part 18 receives the intermediate
data image-processed by the image processing part 17. The
resolution converting part 18 implements resolution conversion of
the image-processed intermediate data to produce a quickview Image
that has been adjusted in image size in accordance with the monitor
resolution.
[0154] It should be noted that when the intermediate data and the
quickview Image are equal to each other in resolution, the
resolution conversion thereon is omitted.
[0155] The video controller 31 uses the SDRAM 26 or the like as a
video memory to cause the quickview Image to be monitor-displayed.
The user may view this monitor display to quickly review the last
captured image.
[0156] Furthermore, the resolution converting part 18 reduces the
number of the pixels of the produced quickview image to produce a
thumbnail image for a display list.
[0157] (8) Compression of Thumbnail
[0158] The microprocessor 50 receives the thumbnail image from the
resolution converting part 18 to implement compression of the
thumbnail image based on a software processing. The compressed data
of the thumbnail image are transferred to the SDRAM 26 to be
temporarily stored therein.
[0159] It should be appreciated that the microprocessor 50 may use
the SDRAM 26 as an input buffer to receive the thumbnail image. In
such a case, the microprocessor 50 may receive the thumbnail image
from the SDRAM 26 to implement the compression thereon
independently of the timing at which the thumbnail image is
produced by the resolution converting part 18. As a result, the
microprocessor 50 may efficiently implement the compression on the
thumbnail image, for example, during an interval between system
controls such as switch monitoring and the like.
[0160] (9) Compression of quickview
[0161] The image compressing part 19 receives the quickview Image
from the resolution converting part 18 to implement the image
compression thereof. The image compressing part 19 transfers the
compressed data of the quickview Image to the SDRAM 26, which
temporarily stores them therein.
[0162] It should be noted that the foregoing "Compression of
Thumbnail" and "Compression of quickview" are preferably
implemented in parallel.
[0163] (10) Recording of Compressed Data of quickview
[0164] The microprocessor 50 (or DMA controller 26b) derives the
compressed data of the quickview image from the SDRAM 26, and
transfers them to the card interface 43 to sequentially record them
in the memory card 47.
[0165] (11) Recording of Compressed Data of Thumbnail Image
[0166] After completing recording of the compressed data of the
quickview image, the microprocessor 50 (or DMA controller 26b)
derives the compressed data of the thumbnail image from the SDRAM
26, and transfers them to the card interface 43, which sequentially
records them in the memory card 47.
[0167] (12) Production of Image Data for Record
[0168] After completing the image processings on the intermediate
data, the image processing part 17 reads the image data
buffer-stored in the SDRAM 26. The image processing part 17 then
implements image processings on the image data, such as color
interpolation processing, color correction processing, filter
processing and so on, to produce the image data for record.
[0169] (13) Compression of Image Data for Record
[0170] After completing the image compression of the quickview
image, the image compressing part 19 receives the image data for
record from the image processing part 17 to implement image
compression thereof. The image compressing part 19 transfers the
compressed data of the image data for record to the SDRAM 26, which
temporarily stores them therein.
[0171] (14) Recording of Compressed Data of Image Data for
Record
[0172] The microprocessor 50 (or DMA controller 26b) derives the
compressed data of the image data for record from the SDRAM 26, and
transfers them to the card interface 43 to sequentially record them
in the memory card 47.
[0173] The series of operations explained above completes the
operation of the single shooting mode.
[0174] [Explanation of Operation of Continuous Shooting]
[0175] Next, an operation of the continuous shooting mode will be
explained below.
[0176] FIG. 6 is a diagram showing signal processing paths of the
electronic camera 11 in the continuous shooting mode.
[0177] FIG. 7 is a timing chart of the electronic camera 11 in the
continuous shooting mode.
[0178] The operation of the continuous shooting mode will be now
explained below with reference to FIGS. 3, 6 and 7.
[0179] (1) Exposure and Scan/Read
[0180] With its shutter release button (not shown) being pressed
on, the electronic camera 11 continuously exposes and scans/reads
the image sensor 13.
[0181] (2) Signal Processing
[0182] The signal processing part 15 implements processings in real
time on the data of the images continuously picked up, such as
defective pixel correction, optical black-level (OB) correction,
gain adjustment, white balance adjustment, gamma correction and so
on.
[0183] (3) Buffer Storage
[0184] The image data continuously outputted from the signal
processing part 15 are supplied through the picture bus 20 and
external bus 25 to the SDRAM 26 to be sequentially stored in
continuous shooting buffer regions of the SDRAM 26.
[0185] (4) Production of Image Data for Record
[0186] The image processing part 17 reads the image data from the
continuous shooting buffer regions of the SDRAM 26 in the
picking-up order. The image processing part 17 then implements
image processings on the image data, such as color interpolation
processing, color correction processing, filter processing and so
on, to produce the image data for record. It should be noted that
in order to increase the number of the frames to be continuously
shot at one time, the continuous shooting buffer regions from which
the image data have been read for those image processings are
immediately released and become usable as the latest continuous
shooting buffer regions.
[0187] It also should be noted that in a case where the image
sensor 13 is of interlace system, the image data of the first field
are temporarily stored in the SDRAM 26, and subsequently the image
data of the second field are outputted from the signal processing
part 15. At this moment, the image processing part 17 preferably
implements the above described image processings each time a
predetermined unit of data becomes available for those image
processings.
[0188] It also should be noted that in a case where the image
sensor 13 is of progressive system, it may receive the image data
directly from the signal processing part 15 as long as the image
processing part 17 has no delay in processings.
[0189] (5) Compression of Image Data for Record
[0190] The image compressing part 19 receives the image data for
record from the image processing part 17 to implement image
compression thereof. The image compressing part 19 transfers the
compressed data of the image data for record to the SDRAM 26, which
temporarily stores them therein.
[0191] (6) Recording of Compressed Data of Image Data for
Record
[0192] The microprocessor 50 (or DMA controller 26b) derives the
compressed data of the image data for record from the SDRAM 26, and
transfers them to the card interface 43 to sequentially record them
in the memory card 47.
[0193] (7) Production of quickview Image
[0194] The resolution converting part 18 receives the image data
for record from the image processing part 17, and implements
resolution conversion of the image data for record to produce a
quickview Image, which is then transferred to the SDRAM 26 and
temporarily stored in the processing buffer regions thereof.
[0195] (8) Production of Thumbnail Image
[0196] The thinning part 16 receives the quickview image from the
resolution converting part 18, and implements pixel number
reduction (pixel thinning, pixel averaging or the like) of the
quickview image to produce a thumbnail image for a display
list.
[0197] It should be noted that the foregoing "Production of
quickview Image" and "Production of Thumbnail Image" are preferably
implemented in a pipeline fashion.
[0198] (9) Compression of Thumbnail
[0199] The microprocessor 50 sequentially receives the thumbnail
image from the thinning part 16 to implement image compression
thereof based on a software processing. The microprocessor 50 (or
DMA controller 26b) transfers the compressed data of the thumbnail
image to the SDRAM 26, which temporarily stores them therein.
[0200] It should be appreciated that the microprocessor 50 may use
the SDRAM 26 as an input buffer to receive the thumbnail image. In
such a case, the microprocessor 50 may receive the thumbnail image
from the SDRAM 26 to implement the compression thereof,
independently of the timing at which the thumbnail image is
produced by the resolution converting part 18. As a result,
microprocessor 50 may efficiently implement the compression of the
thumbnail image, for example, during an interval between system
controls such as a switch monitoring and the like.
[0201] (10) Compression of quickview Image
[0202] The image compressing part 19, after completing the image
compression of the image data for record, reads the quickview Image
from the SDRAM 26 to implement the image compression thereof. The
image compressing part 19 transfers the compressed data of the
quickview Image to the SDRAM 26, which temporarily stores them
therein.
[0203] (11) Recording of Compressed Data of Thumbnail and quickview
Images
[0204] After completing the recording of the compressed data of the
image data for record, the microprocessor 50 (or DMA controller
26b) derives the compressed data of the thumbnail image from the
SDRAM 26, and transfers them to the card interface 43, which
records them in the memory card 47.
[0205] After completing the recording of the compressed data of the
thumbnail image, the microprocessor 50 (or DMA controller 26b)
derives the compressed data of the quickview image from the SDRAM
26, and transfers them to the card interface 43, which records them
in the memory card 47.
[0206] The series of operations explained above completes the
continuous shooting mode.
[0207] [Advantages of Second Embodiment]
[0208] As explained above, in the single shooting mode, the
outputting of the quickview image is commenced prior to that of the
image data for record. Therefore, the quickview image can be
quickly displayed, so that the user can review the captured image
quite smoothly.
[0209] Especially, when producing the quickview image, the
electronic camera 11 produces first the intermediate data where the
number of the pixels has been reduced. As a result, the electronic
camera 11 only needs to implement image processings on the
slimmed-down intermediate data so as to produce the quickview
image. Thus, the quickview image can be quickly completed.
[0210] Besides, in the single shooting mode, the quickview image
and the image data for record are generated at different timings
from each other. Therefore, using the single image processing part
17 the quickview image and image data for record are smoothly
image-processed. This eliminates the necessity for providing
separate image processing parts respectively dedicated to the
quickview image and the image data for record. As a result, the
structure of the electronic camera 11 is simplified.
[0211] Also, in the single shooting mode, the outputting of the
quickview image and that of the image data for record are commenced
in the order named. The image compressing part 19 implements image
compression on them in this order. Therefore, the quickview image
can be compressed to some degree in parallel with the production of
the image data for record. As a result, the whole processing time
can be efficiently shortened.
[0212] Furthermore, in the single shooting mode, the compressed
data of the quickview image and that of the image data for record
are produced in the order named. The card interface 43 records
their compressed data in this order. Therefore, while the image
data for record are being produced, the recording of the compressed
data of the quickview image can be advanced to some degree. As a
result, the whole processing time can be efficiently shortened.
[0213] On the other hand, in the continuous shooting mode, the
image data for record is preferentially generated, and the
quickview images are generated by processing the image data for
record. Thus, the image data for record are generated earlier,
whereby the continuous shooting buffer regions of the SDRAM 26 can
be released quickly one after another, resulting in increasing the
possible number of frames in the continuous shooting.
[0214] As described above, in the second embodiment, the operations
(6) through (11) indicated below are performed for each frame in
the continuous shooting.
[0215] (6) Recording of compressed data of image data for
record
[0216] (7) Production of quickview image
[0217] (8) Production of thumbnail image
[0218] (9) Compression of thumbnail
[0219] (10) Compression of quickview image
[0220] (11) Recording of compressed data of thumbnail and quickview
images
[0221] It, however, should be noted that all or a part of these
operations (6) through (11) may be implemented after the end of the
continuous shooting. In such a case, the time required for each
exposure in the continuous shooting mode can be shortened, so that
the speed of the continuous shooting can be significantly
increased.
[0222] Especially, performing the operations (6), (10) and (11)
after the continuous shooting can further increase the speed of the
continuous shooting because these operations are time-consuming.
(This is because the quickview images cannot be compressed during
compression of the image data for record so that these three
operations are likely to have to be sequential.) On the other hand,
since the operations (7), (8) and (9) can be implemented
concurrently with the compression of the image data for record,
performing these operations (7), (8) and (9) for each frame will
not significantly reduce the speed of the continuous shooting. In a
case where the control operation of the MPU 50 is slow, however, it
is preferable that the operation (9) be implemented after the
completion of the continuous shooting so as not to reduce the speed
of the continuous shooting.
[0223] In the second embodiment, the processing sequences are
different between the single and continuous shootings.
Consequently, the quickview image can be quickly displayed at the
time of the single shooting, while the speed of the continuous
shooting can be increased in the continuous shooting. However, the
present invention is not limited thereto. For example, the
above-described processing sequence of the continuous shooting mode
may be performed in the single shooting mode.
[0224] The invention is not limited to the above embodiments and
various modifications may be made without departing from the spirit
and scope of the invention. Any improvement may be made in part or
all of the components.
* * * * *