U.S. patent application number 14/319910 was filed with the patent office on 2017-01-12 for broadcast receiver and 3d subtitle data processing method thereof.
The applicant listed for this patent is LG ELECTRONICS INC.. Invention is credited to Ho Taek HONG, Jin Pil KIM, Jong Yeul SUH.
Application Number | 20170013244 14/319910 |
Document ID | / |
Family ID | 51686522 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170013244 |
Kind Code |
A9 |
SUH; Jong Yeul ; et
al. |
January 12, 2017 |
BROADCAST RECEIVER AND 3D SUBTITLE DATA PROCESSING METHOD
THEREOF
Abstract
A broadcast receiver and a 3D subtitle data processing method
thereof are disclosed. A method for processing three dimensional
(3D) subtitle data includes receiving, by a receiver, a broadcast
signal including 3D subtitle data, extracting, by an extracting
unit, subtitle display information for a base view and extended
subtitle display information for an extended view from the 3D
subtitle data, and controlling, by a controller, a 3D subtitle
display using the subtitle display information for the base view
and the extended subtitle display information for the extended
view.
Inventors: |
SUH; Jong Yeul; (Seoul,
KR) ; KIM; Jin Pil; (Seoul, KR) ; HONG; Ho
Taek; (Seoul, KR) |
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Applicant: |
Name |
City |
State |
Country |
Type |
LG ELECTRONICS INC. |
Seoul |
|
KR |
|
|
Prior
Publication: |
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Document Identifier |
Publication Date |
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US 20140307051 A1 |
October 16, 2014 |
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Family ID: |
51686522 |
Appl. No.: |
14/319910 |
Filed: |
June 30, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13201320 |
Aug 12, 2011 |
8803948 |
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PCT/KR2009/007109 |
Dec 1, 2009 |
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14319910 |
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61152234 |
Feb 12, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N 21/4345 20130101;
H04N 21/2362 20130101; H04N 21/4314 20130101; H04N 21/816 20130101;
H04N 21/4884 20130101; H04N 13/194 20180501; H04N 13/156 20180501;
H04N 13/183 20180501; H04N 13/161 20180501 |
International
Class: |
H04N 13/00 20060101
H04N013/00 |
Claims
1-10. (canceled)
11. A method of processing a digital broadcast signal for a
3-dimensional (3D) content, the method comprising: encoding video
data for the 3D content into a stream, the video data comprising a
left picture for a left view and a right picture for a right view
for a 3D data; generating signaling information for the video data,
wherein the signaling information includes subtitling descriptor
including subtitling type information, wherein the subtitling type
information indicates an existence of a subtitle for the 3D
content; generating packet data including subtitle segment for
subtitling of the 3D content; transmitting the broadcast signal
including the video data, the packet data and the signaling
information, wherein the subtitle segment includes a segment type
identifying the subtitle segment, a page identifier indicating a
page on which the subtitle is displayed, region information
identifying at least one region within the page, object part
horizontal position indicating a horizontal position of the top
left pixel of an object part in the at least one region and
disparity information indicating a difference between horizontal
positions of subtitles representing a same point in space in the
right and left view of the 3D data for the page.
12. The method of claim 11, wherein the subtitle includes at least
one of displayed image, text data, graphic data and logo.
13. The method of claim 11, wherein the subtitle segment further
includes region size information specifying a horizontal width of
the at least one region which is expressed in pixels.
14. The method of claim 11, wherein the subtitle segment further
includes region disparity information indicating difference between
horizontal positions of regions identified by the region
information.
15. The method of claim 11, wherein the subtitle segment further
includes object part information identifying at least one object
part of the subtitle within the at least one region and object part
disparity information indicates difference between horizontal
positions of object parts identified by the object part
information.
16. An apparatus for receiving a digital broadcast signal for a
3-dimensional (3D) content, the method comprising: a receiving unit
configured to receive a broadcast signal including video data for
the 3D content, the video data comprising a left picture for a left
view and a right picture for a right view for a 3D data; an
extracting unit configured to extract signaling information for the
video data and packet data including subtitle segment for
subtitling of the 3D content, wherein the signaling information
includes subtitling descriptor including subtitling type
information, wherein the subtitling type information indicates an
existence of a subtitle for the 3D content; and a controller
configured to control a display of subtitle in the 3D data for the
3D content based on the subtitling type information and the
subtitle segment, wherein the subtitle segment includes a segment
type identifying the subtitle segment, a page identifier indicating
a page on which the subtitle is displayed, region information
identifying at least one region within the page, object part
horizontal position indicating a horizontal position of the top
left pixel of an object part in the at least one region and
disparity information indicating a difference between horizontal
positions of subtitles representing a same point in space in the
right and left view of the 3D data for the page.
17. The method of claim 16, wherein the subtitle includes at least
one of displayed image, text data, graphic data and logo.
18. The method of claim 16, wherein the subtitle segment further
includes region size information specifying a horizontal width of
the at least one region which is expressed in pixels.
19. The method of claim 16, wherein the subtitle segment further
includes region disparity information indicating difference between
horizontal positions of regions identified by the region
information.
20. The method of claim 16, wherein the subtitle segment further
includes object part disparity information indicates difference
between horizontal positions of object parts identified by the
object part information.
Description
TECHNICAL FIELD
[0001] The present invention relates to a broadcast receiver and a
three dimensional (3D) subtitle data processing method thereof, and
more particularly to a broadcast receiver for receiving 3D subtitle
data and processing the received 3D subtitle data in consideration
of either a display condition of a 3D video display device or an
effect intended by transmission of subtitle data, and a method for
processing the 3D subtitle data.
BACKGROUND ART
[0002] Generally, a three dimensional (3D) image (or a stereoscopic
image) provides a user's eyes with a stereoscopic effect using the
stereoscopic visual principle. A human being feels both near and
far through a binocular parallax caused by a distance between their
eyes spaced apart from each other by about 65 mm, such that the 3D
image enables both right and left eyes to respectively view
associated planar images, resulting in the stereoscopic effect and
the perspective effect.
[0003] The above-mentioned 3D image display method may be
classified into a stereoscopic scheme, a volumetric scheme, a
holographic scheme, etc. In case of using the stereoscopic scheme,
the 3D image display method provides a left view image to be viewed
by the left eye and a right view image to be viewed by the right
eye, such that the user's left eye views the left view image and
the user's right eye views the right view image through either
polarization glasses or a display device, resulting in recognition
of the 3D image effect.
DISCLOSURE OF INVENTION
Technical Problem
[0004] Accordingly, the present invention is directed to a
broadcast receiver and a 3D subtitle data processing method thereof
that substantially obviate one or more problems due to limitations
and disadvantages of the related art.
[0005] An object of the present invention is to provide a broadcast
receiver for receiving 3D subtitle data under a 3D broadcast
environment, processing the received 3D subtitle data in
consideration of a display condition of a 3D video display device
and a 3D effect intended by a content manufacturer, displaying the
processed 3D subtitle data, and thus providing a user with more
effective and convenient broadcast environments, and 3D subtitle
data processing method for use in the broadcast receiver.
Solution to Problem
[0006] The object of the present invention can be achieved by
providing a method for processing three dimensional (3D) subtitle
data, the method including receiving, by a receiver, a broadcast
signal including 3D subtitle data, extracting, byan extracting
unit, subtitle display information for a base view and extended
subtitle display information for an extended view from the 3D
subtitle data, and controlling, by a controller, a 3D subtitle
display using the subtitle display information for the base view
and the extended subtitle display information for the extended
view.
[0007] In another aspect of the present invention, provided herein
is a broadcast receiver including a receiver for receiving a
broadcast signal including 3D subtitle data, an extracting unit for
extracting subtitle display information for a base view and
extended subtitle display information for an extended view from the
3D subtitle data, and a controller for controlling a 3D subtitle
display using the subtitle display information for the base view
and the extended subtitle display information for the extended
view.
Advantageous Effects of Invention
[0008] According to embodiments of the present invention, the
broadcast receiver can process subtitle data according to a 3D
effect of received 3D subtitle data, and display the processed
subtitle data.
[0009] In addition, according to embodiments of the present
invention, a 3D subtitle data processing method maintains
compatibility with a 2D legacy broadcast receiver, and at the same
time displays subtitle data having a 3D effect through a broadcast
receiver capable of displaying 3D video data.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The accompanying drawings, which are included to provide a
further understanding of the invention, illustrate embodiments of
the invention and together with the description serve to explain
the principle of the invention.
[0011] In the drawings:
[0012] FIG. 1 shows a syntax structure of an extended Display
Definition Segment (DDS) acting as extended subtitle display
information according to one embodiment of the present
invention.
[0013] FIG. 2 shows a syntax structure of an extended Page
Composition Segment (PCS) acting as extended subtitle display
information according to one embodiment of the present
invention.
[0014] FIG. 3 shows a syntax structure of an extended Region
Composition Segment (RCS) acting as extended subtitle display
information.
[0015] FIG. 4 shows a syntax structure of an extended Object Data
Segment (ODS) acting as extended subtitle display information
according to one embodiment of the present invention.
[0016] FIG. 5 is a flowchart illustrating a method for receiving
and processing 3D subtitle data according to one embodiment of the
present invention.
[0017] FIG. 6 is a block diagram illustrating a broadcast receiver
for receiving and processing 3D subtitle data according to one
embodiment of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0018] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. The detailed description,
which will be given below with reference to the accompanying
drawings, is intended to explain exemplary embodiments of the
present invention, rather than to show the only embodiments that
can be implemented according to the present invention.
[0019] Prior to describing the present invention, it should be
noted that most terms disclosed in the present invention are
defined in consideration of functions of the present invention and
correspond to general terms well known in the art, and can be
differently determined according to intention of those skilled in
the art, usual practices, or introduction of new technologies. In
some cases, a few terms have been selected by the applicant as
necessary and will hereinafter be disclosed in the following
description of the present invention. Therefore, it is preferable
that the terms defined by the applicant be understood on the basis
of their meanings in the present invention.
[0020] The 3D image display method includes a stereoscopic imaging
scheme in which two view points are considered and a multi-view
imaging scheme in which three or more view points are considered.
In contrast, a single view image scheme shown in the related art
may also be referred to as a monoscopic image scheme.
[0021] The stereoscopic imaging scheme is designed to use one pair
of right and left view images acquired when a left-side camera and
a right-side camera spaced apart from each other by a predetermined
distance capture the same target object. The multi-view imaging
scheme uses three or more images captured by three or more cameras
spaced apart by a predetermined distance or angle. Although the
following description discloses embodiments of the present
invention using the stereoscopic imaging scheme as an example, the
inventive concept of the present invention may also be applied to
the multi-view imaging scheme.
[0022] A stereoscopic image or multi-view image may be compressed
and coded according to a variety of methods including a Moving
Picture Experts Group (MPEG) scheme, and transmitted to a
destination.
[0023] For example, a stereoscopic image or a multi-view image may
be compressed and coded according to the H.264/Advanced Video
Coding (AVC) scheme, and transmitted. In this case, the reception
system may decode a received image in reverse order of the
H.264/AVC coding scheme, such that it is able to obtain the 3D
image.
[0024] In addition, one of a left view image and a right view image
of a stereoscopic image or one of multiple-view images may be
assigned to an image of a base layer, and the remaining one may be
assigned to an image of an extended layer. The base layer image may
be encoded using the same method as the monoscopic imaging method.
In association with the extended layer image, only information of
the relationship between the base layer image and the extended
layer image may be encoded and transmitted. As an exemplary
compression coding scheme for the base layer image, a JPEG, an
MPEG-2, an MPEG-4, or a H.264/AVC scheme may be used. For
convenience of description, the H.264/AVC scheme may be exemplarily
used in one embodiment of the present invention. In one embodiment
of the present invention, the compression coding scheme for an
image of an upper or higher layer may be set to the
H.264/Multi-view Video Coding (MVC) scheme.
[0025] When the MVC scheme is additionally applied to the AVC
scheme or the right/left image sequences are coded using only the
AVC scheme so as to implement the stereoscopic display, one point
to be duly considered when broadcasting corresponding 3D content
data is compatibility with the 2D broadcast receiver of the related
art. For the related broadcast receiver incapable of supporting the
3D image display, if one of right and left view images is encoded
and transmitted according to a backward compatible method, the 2D
broadcast receiver recognizes and outputs only the corresponding
signal, such that it may be possible for a user to view the
corresponding content data through the related device. In the
following description, a base layer image of a time point where
content data is transferred for a legacy broadcast receiver may be
referred to as base view video data (or a base video), and an
extended layer image transferred for displaying a 3D image may be
referred to as extended view video data (or an extended video).
[0026] In the case of transferring the base view video data and the
extended view video data as described above, a legacy 2D broadcast
receiver receives the base video data so that it can display a 2D
image, and a 3D broadcast receiver receives base view video data
and extended view video data so that it can display a 3D image.
However, unexpected problems may occur in a method for displaying
subtitle data.
[0027] A Digital Video Broadcasting (DVB) system will hereinafter
be used as an example of a system for transmitting, receiving, and
processing subtitle data.
[0028] The term `Subtitle` in the following description may include
not only a subtitle but also displayed image, text data, graphic
image, logo, etc which are additionally displayed to basic video
data.
[0029] The DVB broadcast system transmits subtitle data as a
variety of information of a subtitle. At this time, the subtitle
data may include not only subtitle display information including
configuration, size, position, etc. needed for displaying a
subtitle, but also information of a display color of a subtitle.
The subtitle display information includes display definition
information associated with a display window structure needed for
displaying a subtitle, page composition information, region
composition information, object data information, and the like.
From the viewpoint of a syntax structure for data transmission,
display definition information may be referred to as a display
definition segment, page composition information may be referred to
as a page composition segment, region composition information may
be referred to as a region composition segment, and object data
information may be referred to as an object data segment.
[0030] A related DVB broadcast signal provides only basic subtitle
display information. Accordingly, when a 3D broadcast receiver
desires to display the basic subtitle display information, the
basic subtitle display information may be represented by a 2D
broadcast signal or may not be displayed. Therefore, it is
necessary to transmit information capable of allowing even the
subtitle display information to be displayed in a 3D format, and a
broadcast receiver capable of displaying subtitle data in a 3D
format using the above-mentioned information and a data processing
method thereof are needed.
[0031] In the case of displaying a stereoscopic image, left view
video data and right view video data are horizontally shifted by a
predetermined distance so as to implement a 3D effect, and then
displayed. At this time, a variety of representation values (such
as a shifted distance) capable of indicating the 3D effect may be
used. In accordance with the embodiment of the present invention, a
disparity value will hereinafter be used as such a representation
value of the 3D effect.
[0032] The 3D effect may be acquired from the process in visual
perception leading to the sensation of depth from two slightly
different projections of the world onto the retinas of the eyes.
The difference in the two retinal images may be called horizontal
disparity, retinal disparity, or binocular disparity. Hereinafter,
for convenience of description and better understanding of the
present invention, the difference between the two retinal images
will only be referred to as `disparity`.
[0033] For example, in the case of transmitting 3D video data,
respective scenes of the 3D video data may have different 3D
effects. In this case, disparity values for corresponding scenes
are transmitted to a broadcast receiver, so that the broadcast
receiver controls and displays the 3D effect using the disparity
values. Although other representation values (for example, a depth
value, a pixel interval, a screen size, etc.) instead of the above
disparity values may be used to display the 3D effect, it should be
noted that the embodiments of the present invention will
exemplarily use the disparity value for convenience of description
and better understanding of the present invention.
[0034] In the case of transmitting subtitle data using the related
DVB transmission scheme, the 3D broadcast receiver receives base
view video data and extended view video data and displays the
received base view video data and the received extended view video
data as 3D video data. However, the subtitle data has no
information for a 3D display, such that it has a disadvantage in
that it must display 3D video data as a 2D format. In this case,
the subtitle can be displayed only as base view video data or an
extended view video data, and a user views the subtitle in a 2D
format in a different way from a 3D image, so that the user may
experience dizziness and feel fatigue of eyes.
[0035] Accordingly, it is necessary to transmit both 3D video data
and information of a 3D effect to the related subtitle data. In
this way, the 3D effect information may be inserted into the
related subtitle display information or it is possible to transmit
additional subtitle display information.
[0036] In accordance with a method for transmitting additional
subtitle data, the stereoscopic image requires two viewpoint video
data (i.e., left view video data and right view video data) to
display the 3D effect, so that related subtitle display information
may be used as subtitle display information of one viewpoint, and
subtitle display information of another viewpoint may be
additionally transmitted. For example, the related subtitle display
information may be set to a subtitle for displaying data at a base
view, and subtitle display information of a subtitle to be
displayed at an extended view may be additionally transmitted. In
accordance with the above-mentioned method, when two subtitle
display information is transmitted and at the same time 3D effect
information is inserted into one or two subtitle display
information and the inserted result is transmitted, a 3D receiver
can display subtitle data having the 3D effect in the same manner
as in a method for displaying stereoscopic video data.
[0037] A method for transmitting the additional subtitle display
information may be advantageous to a method in which related
subtitle display information is modified and transmitted. In other
words, the related 2D broadcast receiver is designed to process and
display only related subtitle display information without
processing additional subtitle display information undefined in the
related subtitle display information, such that the above method
for transmitting additional subtitle display information can be
easily compatible with the related 2D receiver.
[0038] Therefore, the following embodiment of the present invention
will disclose a method for transmitting subtitle data by
constructing not only related subtitle display information but also
other subtitle display information for a 3D display. The
above-mentioned additional subtitle display information may also be
referred to as extended subtitle display information.
[0039] FIG. 1 shows a syntax structure of an extended Display
Definition Segment (DDS) acting as extended subtitle display
information according to one embodiment of the present
invention.
[0040] The DDS includes display width information and display
height information of a TV image in which a DVB subtitle is
rendered. In other words, the DDS indicates a display size of a
video image including a subtitle stream to be displayed. In one
embodiment of the present invention, an extended DDS (DDS EXT)
shown in FIG. 1 is transmitted, so that a receiver can control an
output of a subtitle at an extended view.
[0041] Individual fields of the extended DDS shown in FIG. 1 are as
follows.
[0042] A `dds_version_number` field may indicate aversion of the
extended DDS.
[0043] A `display_window_flag` field may indicate whether a
subtitle display set associated with the extended DDS is intended
to be rendered in a window within the display size defined by
`display_width` and `display_height` fieldsor to be rendered
directly within the display size defined by `display_width` and
`display_height` fields.
[0044] A `display_width` field may indicate a maximum horizontal
width in pixels of a display assumed by a subtitling stream
associated with the extended DDS.
[0045] A `display_height` field may indicate a maximum vertical
height in lines of a display in lines of a display assumed by a
subtitling stream associated with the extended DDS.
[0046] A `display_window_horizontal_position_minimum` field may
indicate a left-hand most pixel of a subtitle display set with
reference to a left-hand most pixel of a display.
[0047] A `display_window_horizontal_position_maximum` field may
indicate a right-hand most pixel of a subtitle display set with
reference to a left-hand most pixel of a display.
[0048] A `display_window_vertical_position_minimum` field may
indicate an upper most line of a subtitle display set with
reference to a top line of a display.
[0049] A `display_window_vertical_position_maximum` field may
indicate a bottom line of a subtitle display set with reference to
a top line of a display.
[0050] The above-mentioned fields may be pre-contained in the DDS,
and then be transmitted. In this case, information of the same or
duplicated fields having been transmitted in the DDS is omitted and
as such only the following information may be transmitted.
[0051] A `page_id` field 1020 may indicate an identifier (ID) of a
page on which a subtitle is displayed. In case of a `page_id`
value, the subtitle will be displayed on the same page at a base
view and an extended view, so that the `page_id` value may be
identical to a `page_id` value of a DDS corresponding to the base
view, and then be transmitted.
[0052] A `segment_type` field 1010 may have a value different from
a related DDS value (e.g., 0.times.14), and must have a specific
value (e.g., 0.times.44) capable of identifying an extended
DDS.
[0053] A `target_view_position` field 1030 may indicate a view
position to which the extended DDS is applied. In other words, the
`target_view_position` field 1030 indicates viewpoint information
for displaying a stereoscopic subtitle. For example, if the
subtitle display of a corresponding extended DDS is applied to a
left image, the `target_view_position` field 1030 may be set to a
value of `0`. If the subtitle display of a corresponding extended
DDS is applied to a right image, the `target_view_position` field
1030 may be set to a value of `1`.
[0054] A `minimum_disparity_value` field 1040 may indicate a
minimum value of a disparity capable of being represented by a left
image and a right image. The lower the disparity value of the
`minimum_disparity_value` field 1040 (i.e., the closer the
disparity value of the `minimum_disparity_value` field 1040 is to a
negative value), the image forming position gradually moves to the
front of the screen.
[0055] A `maximum_disparity_value` field 1050 may indicate a
maximum value of a disparity value capable of being represented by
a left image and a right image. The higher the disparity value of
the `maximum_disparity_value` field 1050 (i.e., the closer the
disparity value of the `maximum_disparity_value` field 1050 is to a
positive value), the image forming position gradually moves to the
interior of the screen.
[0056] The extended DDS may define the range of a disparity value
capable of being allocated when a subtitle is displayed through the
`minimum_disparity_value` field 1040 and the
`maximum_disparity_value` field 1050.
[0057] As described above, in association with the DDS, the
extended DDS includes not only viewpoint allocation information for
individual subtitles, but also 3D effect information (i.e.,
disparity values), such that a receiver can display a subtitle
having the 3D effect.
[0058] FIG. 2 shows a syntax structure of an extended Page
Composition Segment (PCS) acting as extended subtitle display
information according to one embodiment of the present
invention.
[0059] Referring to FIG. 2, the PCS includes information of
constituent components of a displayed subtitle. The PCS may include
usage- and positioning- information of at least one region
constructing the displayed page. In accordance with one embodiment
of the present invention, the extended PCS (PCS_EXT) shown in FIG.
2 is transmitted, such that the receiver can control an output of a
subtitle at an extended view.
[0060] Individual fields of the extended PCS shown in FIG. 2 are as
follows.
[0061] A `page_id` field may indicate an identifier (ID) of a page
on which a subtitle is displayed. In case of a `page_id` value, the
subtitle will be displayed on the same page at a base view and an
extended view, so that the `page_id` value may be identical to a
`page_id` value of a DDS corresponding to the base view, and then
be transmitted.
[0062] A `page_time_out` field may indicate a period, expressed in
seconds, after which a page instance is no longer valid and
consequently shall be erased from the screen, should it not have
been redefined before that.
[0063] A `page_version_number` field may indicate a version of the
extended PCS.
[0064] A `page_state` field may indicate a status of a subtitling
page instance described in the extended PCS.
[0065] A `region_id` field may indicate a unique identification of
a region within a page. The `region_id` field may display a
subtitle in the same region at the base view and the extended view,
such that it is identical to a `region_id` value of a PCS
corresponding to the base view and then transmitted.
[0066] A `region_horizontal_address` field indicates a horizontal
address of a top left pixel of this region. The left-most pixel of
the active pixels has a horizontal address of zero, and the pixel
address increases from left to right.
[0067] A `region vertical address` field may indicate a vertical
address of a top line of this region. The top line of the frame is
a line of zero, and the line address increases by one within the
frame from top to bottom.
[0068] A `target_view_position` field 2010 may indicate a view
position at which the extended PCS is applied. That is, the
`target_view_position` field 2010 may indicate viewpoint
information for displaying a stereoscopic subtitle. For example, if
a subtitle display of a corresponding extended PCS is applied to a
left image, the `target_view_position` field 2010 may be set to a
value of `0`. If a subtitle display of a corresponding extended PCS
is applied to a right image, the `target_view_position` field 2010
may be set to a value of `1`.
[0069] A `region_disparity_value` field 2020 may indicate a
disparity between a first region applied to the left image and a
second region applied to the right image. The
`region_disparity_value` field 2020 may indicate a horizontal
displacement of other view on the basis of a target view. In the
case of transmitting a value of `region_disparity_value` field
2020, a `region_horizontal_address` field and a
`region_vertical_address` field may be redundant, so that the
redundant fields may be omitted as necessary.
[0070] For example, it is assumed that the `target_view_position`
field of the extended PCS has a value of 1, the
`region_disparity_value` field has a value of 20, and the
`region_horizontal_address` field has a value of N. In this case, a
subtitle for the extended PCS is displayed as a right image, and a
subtitle for the PCS is displayed as a left image. In this case,
the horizontal position of the subtitle displayed on the left image
is `N`, the horizontal position of the subtitle displayed on the
right image is `N -20`, so that a binocular parallax is generated
in response to a difference in horizontal positions between the
left image and the right image, resulting in the occurrence of a 3D
effect.
[0071] FIG. 3 shows a syntax structure of an extended Region
Composition Segment (RCS) acting as extended subtitle display
information.
[0072] The RCS includes a list of displayed objects and position
information of the objects. In accordance with one embodiment of
the present invention, the extended RCS (RCS EXT) shown in FIG. 3
is transmitted, so that the receiver can control an output of a
subtitle at the extended view.
[0073] Individual fields of the extended RCS shown in FIG. 3 are as
follows.
[0074] A `region_id field` may identify a region for which
information is contained in this
[0075] RCS EXT.
[0076] A `region_version_number` field may indicate a version of
this region.
[0077] If a `region_fill_flag` field is set to a value of `1`, the
`region_fill_flag` field means signals indicating that the region
is to be filled with the background color defined in the `region
n-bit pixel code` fields in this segment.
[0078] A `region_width` field may specify a horizontal length of
this region, and is expressed in number of pixels.
[0079] A `region_height` field may specify a vertical length of the
region, and is expressed in number of pixels.
[0080] A `region_level_of_compatability` field may indicate a
minimum type of Color Look Up Table (CLUT) that is necessary in the
decoder to decode this region.
[0081] A `region_depth` field may identify an intended pixel depth
for this region.
[0082] A `CLUT_id` field may identify a family of CLUTs applied to
this region.
[0083] A `region_n(8,4 and 2)-bit pixel code` field may specify the
entry of the applied n-bit CLUT as background color for the region
when the `region_fill_flag` field is set.
[0084] A `processed_length` field is the number of bytes from the
field(s) within a while-loop that has been processed by the
decoder.
[0085] An `object_id` field may identify an object shown in the
region.
[0086] An `object_type` field may identify a type of object.
[0087] An `object_provider_flag` field may indicate how this object
is provided.
[0088] An `object_horizontal_position` field may specify a
horizontal position of the top left pixel of this object, and is
expressed in number of horizontal pixels, relative to a left hand
edge of the associated region.
[0089] An `object_vertical_position` field may specify a vertical
position of the top left pixel of this object, and is expressed in
number of lines, relative to the top of the associated region.
[0090] A `foreground_pixel_code` field may specify the entry in the
applied CLUT that has been selected as the foreground color of the
character(s).
[0091] A `background_pixel_code` field may specify the entry in the
applied CLUT that has been selected as the background color of the
character(s).
[0092] A `target_view_position` field 3010 may indicate a view
position at which the extended RCS is applied. That is, the
target_view_position' field 3010 may indicate viewpoint information
for displaying a stereoscopic subtitle. For example, if the
subtitle display of a corresponding extended RCS is applied to a
left image, the `target_view_position` field 3010 may be set to a
value of `0`. If a subtitle display of a corresponding extended RCS
is applied to a right image, the `target_view_position` field 3010
may be set to a value of `1`.
[0093] An `object_disparity_value` field 3020 may indicate a
disparity between a first object applied to a left image and a
second object applied to a right image. A value of the
`object_disparity_value` field 3020 may indicate a horizontal
displacement of other view on the basis of a target view.
[0094] FIG. 4 shows a syntax structure of an extended Object Data
Segment (ODS) acting as extended subtitle display information
according to one embodiment of the present invention.
[0095] The ODS may include data of a plurality of displayed
objects. In one embodiment of the present invention, an extended
ODS (ODS EXT) shown in FIG. 4 is transmitted, so that a receiver
can control an output of a subtitle at an extended view.
[0096] In case of the ODS, if a disparity field is added in units
of each object contained in the region of the extended RCS, a
disparity can be adjusted in units of each object using the
disparity field, so that different 3D effects can be assigned to
each objects contained in the region. Therefore, the ODS for a base
view can be applied even to a process for displaying a subtitle at
an extended view without any change. At this time, an identifier
(ID) identical to that of the ODS used in the base view may be
established in the extended RCS, and then transmitted.
Alternatively, the broadcast receiver may copy or read a received
ODS, such that it may control a subtitle display for the extended
view. However, different objects may be used at respective
viewpoints. At this time, the extended ODS may transmit data of an
additional object. In the embodiment of the present invention, the
ODS used for displaying a subtitle for the extended view may be
referred to as an extended ODS. In this case, the term `extended
ODS` may include the above-mentioned examples in the following
description.
[0097] Individual fields of the extended ODS are as follows.
[0098] An `object_id` field may identify within the page an object
for which data is contained in this `ODS_EXT` field.
[0099] An `object_version_number` may indicate a version of this
segment data.
[0100] An `object_coding_method` may specify a method used for
coding the object.
[0101] When a `non_modifying_colour_flag` field is set to a value
of 1, this `non_modifying_colour_flag` field indicates that the
CLUT entry value `1` is a non-modifying color.
[0102] A `top_field_data_block_length` field may specify the number
of bytes contained in the `pixel-data_sub-blocks` field for the top
field.
[0103] A `bottom_field_data_block_length` field may specify the
number of bytes contained in the `data_sub-block` field for the
bottom field.
[0104] A `processed_length` field may indicate the number of bytes
from the field(s) within a while-loop that has been processed by
the decoder.
[0105] An `stuff_bits` field may indicate eight stuffing bits that
shall be coded as `0000 0000`.
[0106] A `number_of_codes` field may specify the number of
character codes in the string.
[0107] A `character_code` field may specify a character through its
index number in the character table identified in the
`subtitle_descriptor` field.
[0108] Configuration of subtitle display information for displaying
a stereoscopic subtitle in accordance with one embodiment of the
present invention and a method for processing the subtitle display
information will hereinafter be described.
[0109] The configuration and process of a Display Definition
Segment (DDS) and a Page Composition Segment (PCS) for displaying a
stereoscopic subtitle according to one embodiment of the present
invention will hereinafter be described.
[0110] In order to allow a receiver to display a stereoscopic
subtitle, the receiver must receive subtitle information of two
views, i.e., one subtitle information for a base view and the other
subtitle information for an extended view. A transmission system
can transmit a DDS and a PCS for the base view and the extended DDS
and the extended PCS for the extended view.
[0111] In this case, in the case where a value incapable of being
recognized by a related 2D broadcast receiver is established in a
segment type of each of the extended DDS and the extended PCS, and
is then transmitted, the related 2D broadcast receiver discards the
extended DDS and the extended PCS, and controls a subtitle display
using the DDS and the PCS. The 3D broadcast receiver controls a
subtitle display for the base view using the DDS and the PCS, and
controls a subtitle display for the extended view using the
extended DDS and the extended PCS, so that it can display a
subtitle having the 3D effect.
[0112] Next, the configuration and process of a Region Composition
Segment (RCS) for displaying a stereoscopic display according to
another embodiment of the present invention will hereinafter be
described.
[0113] The RCS may include information about a list of displayed
objects and information about positions of the objects in the
region. In the case of transmitting the extended PCS, a segment
type value incapable of being analyzed by the related 2D broadcast
receiver may be established in the extended RCS corresponding to a
region identifier (ID) contained in the extended PCS so as to
prevent operations of the related 2D broadcast receiver from being
affected, and the established segment type value is then
transmitted. In the case of transmitting the extended RCS in
accordance with one embodiment of the present invention, the
segment type value may be set to `0.times.41`. In this case, the
extended RCS may have the same structure as in the related RCS. In
this embodiment of the present invention, the extended RCS may
correspond to a structure acquired when the `target_view_position`
field 3010 and the `object_disparity_value` field 3020 are deleted
from the table structure shown in FIG. 3.
[0114] In addition, region composition information for the extended
view may be transmitted using the RCS (i.e., segment
type=0.times.11) instead of using the extended RCS. In this case,
the region ID of this RCS is unavailable in the received PCS, so
that the related 2D broadcast receiver can discard the above
RCS.
[0115] The configuration and process of an Object Data Segment
(ODS) for displaying a stereoscopic subtitle according to another
embodiment of the present invention will hereinafter be described
in detail.
[0116] The RCS or the extended RCS includes object information for
constructing the region, and detailed information of a
corresponding object may be contained in the ODS and then be
transmitted. In this case, in order to prevent operations of the
related 2D broadcast receiver from being affected, the extended ODS
for describing a subtitle object for the extended view may be
transmitted. The extended ODS has the same structure as in the
related ODS, and may be assigned another segment type value (e.g.,
0.times.43) different from that of the related ODS and then be
transmitted.
[0117] In addition, object information for the extended view may be
transmitted using the related ODS instead of using the extended
ODS. In this case, the object ID of the received ODS is
unavailable, so that the related 2D broadcast receiver can discard
the above ODS.
[0118] In accordance with one embodiment of the present invention,
a variety of combinations may be constructed according to
configurations of the above-mentioned `DDS_EXT`, `PCS_EXT`
`RCS_EXT` (or `RCS`), and `ODS_EXT` (or `ODS`) and methods for
transmitting these segments. That is, the `DDS_EXT`, `PCS_EXT`,
`RCS_EXT`, and `ODS_EXT` are not constructed to have the same 3D
effect, and are constructed to have different 3D effects. For
example, different disparity values may be assigned to the
`DDS_EXT`, `PCS_EXT`, `RCS_EXT`, and `ODS_EXT`. As a result, a
variety of 3D subtitle combinations which have different 3D effects
according to pages, regions, and objects of individual subtitles
can be displayed.
[0119] FIG. 5 is a flowchart illustrating a method for receiving
and processing 3D subtitle data according to one embodiment of the
present invention.
[0120] Referring to FIG. 5, the broadcast receiver receives a DVB
broadcast stream, and extracts subtitle data from the received
broadcast stream at step S5010. In more detail, the broadcast
receiver parses a Program Map Table (PMT) from the DVB broadcast
stream, obtains a PID value of a stream having a stream type
(stream type=0.times.06), and receives a Packet Elementary Stream
(PES) corresponding to a DVB subtitle. In this case, the broadcast
receiver can obtain basic information of a subtitle from the PMT.
In accordance with one embodiment of the present invention, the
broadcast receiver determines whether current data is a 3D subtitle
by referring to a `subtitling type` field of a
`subtitling_descriptor` field contained in the PMT, so that it can
inform a user of information about the availability or
non-availability of a 3D subtitle. The broadcast receiver reads a
PES packet, which has a value `0.times.20` of a `data_identifier`
field and a value `0.times.00` of a `subtitle stream id` value, so
that it can extract subtitle data using the read PES packet.
[0121] The broadcast receiver performs section-filtering of the
extracted subtitle data at step S5020. The broadcast receiver
performs filtering of detailed information contained in subtitle
data, and outputs the filtered information to a corresponding
buffer. In this case, the subtitle data may be classified as
follows according to values of the `segment type` field.
[0122] 0.times.10 Page Composition Segment (PCS) for Base View
[0123] 0.times.11 Region Composition Segment (RCS) for Base
View
[0124] 0.times.12 CLUT definition segment for both Base View and
Extended View
[0125] 0.times.13 Object Data Segment (ODS) for Base View
[0126] 0.times.14 Display Definition Segment (DDS) for Base
View
[0127] 0.times.40 extended Page Composition Segment (PCS EXT) for
Extended View
[0128] 0.times.41 extended Region Composition Segment (RCS EXT) for
Extended View
[0129] 0.times.43 extended Object Data Segment (ODS EXT) for
Extended View
[0130] 0.times.44 extended Display Definition Segment (DDS EXT) for
Extended View
[0131] The broadcast receiver decodes subtitle display information
for a base view from the classified DDS, PCS, RCS, and ODS at step
S5030. The broadcast receiver decodes the DDS, the PCS, the RCS,
and the DDS, so that it can obtain size information of a subtitle
to be displayed, position information of the subtitle, object
configuration information, object's unique information, and the
like. Information needed for the broadcast receiver to display a
subtitle at a base view may also be called subtitle control
information.
[0132] The broadcast receiver decodes the ODS, and parses a Color
Look Up Table (CLUT), so that it determines subtitle display color
information at a base view at step S5040. The broadcast receiver
decodes `pixel-data_sub-block` data contained in the ODS, so that
it can acquire a pseudo-color value of a subtitle to be displayed
on a base view graphic plane. The broadcast receiver parses the
CLUT, so that it can convert the pseudo-color value into
information of a color to be actually displayed.
[0133] The broadcast receiver decodes extended subtitle display
information for the extended view from the extended DDS, the
extended PCS, the extended RCS (or RCS), and the extended ODS (or
ODS) at step S5050. The broadcast receiver decodes the extended
DDS, the extended PCS, the extended RCS, and the extended ODS (or
ODS), so that it can recognize size information of a subtitle to be
displayed, position information of the subtitle, object
configuration information, object's unique information, and the
like. Information needed for the broadcast receiver to display a
subtitle at the extended view may also be referred to as extended
subtitle control information as necessary.
[0134] The broadcast receiver decodes the extended ODS (or an ODS),
and parses a CLUT, so that it determines subtitle display color
information at a extended view at step S5060. The broadcast
receiver decodes `pixel-data_sub-block` data contained in the
extended ODS (or an ODS), so that it can acquire a pseudo-color
value of a subtitle to be displayed on the extended view graphic
plane. The broadcast receiver parses the CLUT, so that it can
convert the pseudo-color value into information of a color to be
actually displayed.
[0135] In a 3D display, a color of a left view subtitle may be
equal to a color of a right view subtitle. In this case, the
broadcast receiver may determine only once the color information of
a subtitle to be displayed, and may use subtitle color information
of other viewpoint by reading the determined color information. In
this case, step S5060 may herein be omitted or a process for
copying or reading the color information that has been determined
at step S5040 may be carried out.
[0136] The broadcast receiver controls a subtitle for the base view
and a subtitle for the extended view according to individual
subtitle control information, and outputs the controlled subtitles
at step S5070. The broadcast receiver outputs the base view
subtitle along with base view video data according to subtitle
control information and outputs the extended view subtitle along
with extended view video data according to extended subtitle
control information, so that it can display a 3D subtitle.
[0137] In the above-mentioned steps, the step for processing
subtitle display information for a base view subtitle and the other
step for processing extended subtitle display information of an
extended view subtitle need not always be carried out in the above
order. If necessary, subtitle display information for the extended
view may be first carried out, or subtitle display information for
the base view and subtitle display information for the extended
view may be simultaneously carried out.
[0138] FIG. 6 is a block diagram illustrating a broadcast receiver
for receiving and processing 3D subtitle data according to one
embodiment of the present invention.
[0139] Referring to FIG. 6, the broadcast receiver includes a
demultiplexer (denoted by
[0140] `MPEG2 TS Demux (PID filter)`) 6010, a section filter 6020,
an Extended View (EV) subtitle decoder 6030, a Base View (BV)
subtitle decoder 6040, a composition buffer 6050, a CLUT processor
(denoted by `CLUT`) 6060, an EV pixel buffer 6070, a BV pixel
buffer 6080, and a 3D graphics controller 6090.
[0141] Constituent components of the broadcast receiver shown in
FIG. 6 will hereinafter be described in detail. In more detail, the
broadcast receiver shown in FIG. 6 is designed to receive and
process the 3D subtitle data shown in FIG. 5. The same or
duplicated parts as those of FIG. 5 will be briefly descried.
[0142] In the broadcast receiver, a receiving unit (not shown)
receives a Moving Picture Expert Group 2 Transport Stream (MPEG2
TS) including subtitle data, and the demultiplexer 6010 performs
filtering of the received MPEG2 TS using a PID corresponding to
subtitle data so that it extracts and outputs subtitle data.
[0143] The section filter 6020 performs section-filtering of
subtitle data, so that it outputs PCS, PCS EXT, RCS, RCS EXT, DDS,
DDS EXT, ODS, ODS EXT, and Color Look Up Table Definition Segment
(CLUTDS) data.
[0144] In the following description, the demultiplexer 600 for
extracting subtitle data from the received broadcast signal and the
section filter 6020 for extracting and outputting display
information and CLUTDS of a subtitle may be contained in one
extraction unit as necessary.
[0145] In this case, PCS, RCS, DDS, ODS, PCS_EXT, RCS_EXT, DDS_EXT,
and ODS_EXT may be buffered in the composition buffer 6050, and the
buffered results may be applied to the 3D graphics controller 6090.
In addition, PCS, RCS, DDS, and ODS may be applied to the BV
subtitle decoder 6040, and PCS_EXT, RCS_EXT, DDS_EXT, and ODS_EXT
may be applied to the EV subtitle decoder 6030.
[0146] The CLUT processor 6060 processes the CLUTDS, so that it
outputs display color information to the BV pixel buffer 6080 and
the EV pixel buffer 6070.
[0147] The BV subtitle decoder 6040 decodes PCS, RCS, DDS, and ODS,
so that it decodes subtitle data for the base view and subtitle
display information for the base view and outputs the decoded
subtitle data and the decoded subtitle display information to the
BV pixel buffer 6080. The EV subtitle decoder 6030 decodes PCS_EXT,
RCS_EXT, DDS_EXT, and ODS_EXT, so that it decodes subtitle data for
the extended view and subtitle display information for the extended
view and outputs the decoded subtitle data and the decoded subtitle
display information to the EV pixel buffer 6070.
[0148] The 3D graphic controller 6090 receives PCS, RCS, DDS, ODS,
PCS_EXT, RCS_EXT, DDS_EXT, and ODS_EXT from the composition buffer
6050, and receives subtitle display information for the base view,
ODS and color information for the base view from the BV pixel
buffer 6080. The 3D graphics controller 6090 receives subtitle
display information for the extended view, ODS_EXT and color
information for the extended view from the EV pixel buffer 6070.
The 3D graphics controller 6090 reads the received information, so
that it controls subtitles of respective viewpoints and outputs the
controlled subtitles.
[0149] In accordance with another embodiment of the present
invention, the BV subtitle decoder 6040 decodes the ODS and the EV
subtitle decoder 6030 decode the ODS_EXT, so that the BV subtitle
decoder 6040 and the EV subtitle decoder 6030 acquire information
of a displayed subtitle object. The 3D graphics controller 6090
receives coordinates-, size-, and configuration- information (for
example, PCS, RCS, DDS, PCS_EXT, RCS_EXT, and DDS_EXT) of a
displayed subtitle object, so that it may control the 3D subtitle
display using the received information.
[0150] The method disclosed in the present invention may be
implemented in the form of program commands executable by a variety
of computer means, and recorded on a computer-readable recording
medium. The computer-readable recording medium may include program
commands, data files, data structures, etc. individually or in
combination. The program commands recorded on the medium may be
ones specially designed and configured for the present invention or
ones known and available to those skilled in computer software.
Examples of the computer-readable recording medium include magnetic
media such as a hard disk, a floppy disk and a magnetic tape,
optical media such as a compact disc read only memory (CD-ROM) and
a digital versatile disc (DVD), magneto-optical media such as a
floptical disk, and hardware devices specially configured to store
and execute program commands, such as a ROM, a random access memory
(RAM) and a flash memory. Examples of the program commands include
high-level language codes that may be executed by a computer using
an interpreter, etc., as well as machine language codes such as
those produced by a compiler. The above-stated hardware devices may
be configured to operate as one or more software modules to perform
the operation of the present invention, and vice versa.
[0151] Although the present invention has been described in
conjunction with the limited embodiments and drawings, the present
invention is not limited thereto. Those skilled in the art will
appreciate that various modifications, additions and substitutions
are possible from this description. Therefore, the scope of the
present invention should not be limited to the description of the
exemplary embodiments and should be determined by the appended
claims and their equivalents.
MODE FOR THE INVENTION
[0152] Various embodiments have been described in the best mode for
carrying out the invention.
INDUSTRIAL APPLICABILITY
[0153] As apparent from the above description, embodiments of the
present invention may be wholly or partially applied to a digital
broadcasting system.
[0154] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the invention. Thus,
it is intended that the present invention cover the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *