EP2158767A1

EP2158767A1 - Method for describing and multiplexing objects for 3d still image service based on dmb, and apparatus and decoding apparatus and method thereof

Info

Publication number: EP2158767A1
Application number: EP08765953A
Authority: EP
Inventors: Kug-Jin Yun; Hyun Lee; Namho Hur; Jin-Woong Kim; Soo-In Lee
Original assignee: Electronics and Telecommunications Research Institute ETRI
Current assignee: Electronics and Telecommunications Research Institute ETRI
Priority date: 2007-05-29
Filing date: 2008-05-28
Publication date: 2010-03-03
Also published as: KR100826519B1; EP2158767A4; WO2008147103A1

Abstract

Provided is an object description and multiplexing method which provides an object descriptor of a new structure and a multiplexing method for a 3D still image service based on DMB, such as 3D still image advertisement service, and provides 3D a user with still image service through interaction with the user at a specific time or specific video scene while maintaining compatibility with conventional DMB services, and a decoding apparatus and method using the object description and multiplexing method. The method for describing an object to provide a 3D still image service based on DMB, which includes: deciding a broadcasting type of a still image service to be broadcasted between two-dimensional broadcasting and 3D broadcasting based on a program information descriptor in a program map table; and describing reference still image and additional still image that are transmitted separately for the 3D still image service with relation to each other.

Description

Description METHOD FOR DESCRIBING AND MULTIPLEXING OBJECTS

FOR 3D STILL IMAGE SERVICE BASED ON DMB, AND APPARATUS AND DECODING APPARATUS AND METHOD

THEREOF Technical Field

[1] The present invention relates to an object description and multiplexing method for three-dimensional (3D) still image service based on Digital Multimedia Broadcasting (DMB) and a decoding apparatus and method using the same; and, more particularly, to an object description and multiplexing method which provides an object descriptor of a new structure and a multiplexing method for a 3D still image service based on DMB, such as 3D still image advertisement service, and provides 3D a user with a still image service through interaction with the user at a specific time or specific video scene while maintaining compatibility with conventional DMB services, and a decoding apparatus and method using the object description and multiplexing method.

[2] This work was supported by the IT R&D program of MIC/IITA [2005-S-403-02,

"Development of Super-intelligent Multimedia Anytime- anywhere Realistic TV(SmarTV) Technology"]. Background Art

[3] A technology providing three-dimensional (3D) still image service based on Digital

Multimedia Broadcasting (DMB) is disclosed in Korean Patent Publication No. 2006-0013818, entitled "3D DMB System for Supplying a Realistic 3D AV Service to a User with Maintaining Compatibility with a Conventional DMB System by Processing a Stereoscopic 3D Moving Picture and a Sound through the Conventional DMB System", published on February 14, 2006. The technology is not more than independently coding left/right moving pictures and providing a Moving Picture Experts Group (MPEG) 4 system structure to support the left/right moving pictures to video channel for a 3D moving picture broadcasting service.

[4] In other words, there is no technology that can provide still image service in three- dimensional based on DMB.

[5] However, service industries such as 3D stereoscopic advertisement service require a technology to provide 3D still image at a specific display in the middle of moving picture such as video broadcasting. To provide such 3D still image, it is required to develop a method for discriminating between 3D broadcasting program from conventional broadcasting program, which is two-dimensional program, provide a 3D still image service through interaction with users, and develop a multiplexing scheme and MPEG 2 and MPEG 4 systems of new structures to support the 3D still image service. Disclosure of Invention

Technical Problem

[6] An embodiment of the present invention is directed to providing an object description and multiplexing method which provides an object descriptor of a new structure and a multiplexing method for a 3D still image service based on Digital Multimedia Broadcasting (DMB), such as 3D still image advertisement service, and provides a user with 3D still image service through interaction with the user at a specific time or specific video scene while maintaining compatibility with conventional DMB services, and a decoding apparatus and method using the object description and multiplexing method.

[7] Other objects and advantages of the present invention can be understood by the following description, and become apparent with reference to the embodiments of the present invention. Also, it is obvious to those skilled in the art of the present invention that the objects and advantages of the present invention can be realized by the means as claimed and combinations thereof. Technical Solution

[8] In accordance with an aspect of the present invention, there is provided a method for describing an object to provide a three-dimensional (3D) still image service based on Digital Multimedia Broadcasting (DMB), which includes: deciding a broadcasting type of a still image service to be broadcasted between two-dimensional (2D) broadcasting and 3D broadcasting based on a program information descriptor (Programlnfo_descriptor) in a program map table (PMT); and describing reference still image and additional still image that are transmitted separately for the 3D still image service with relation to each other.

[9] In accordance with another aspect of the present invention, there is provided a method for describing an object to provide a 3D still image service based on DMB, which includes: deciding a broadcasting type of a still image service to be broadcasted between 2D broadcasting and 3D broadcasting based on a program information descriptor (Programlnfo_descriptor); and setting up 3D still image to be serviced as independent stream by using one object descriptor.

[10] In accordance with another aspect of the present invention, there is provided a multiplexing method for a 3D still image service based on DMB, which includes: receiving elementary streams for broadcasting programs; checking whether a broadcasting type of a still image service related to a broadcasting program to be broadcasted is 2D broadcasting or 3D broadcasting; and selecting elementary streams related to the broadcasting program whose broadcasting type is confirmed among the inputted elementary streams and multiplexing the selected elementary streams based on a corresponding multiplexing priority order.

[11] In accordance with another aspect of the present invention, there is provided a decoding apparatus for a 3D still image service based on DMB, which includes: a still image decoder for individually recognizing and decoding reference still image stream and additional still image stream to thereby produce reference still image and additional still image; and a 3D format converter for generating a 3D still image by combining the reference still image and the additional still image that are obtained in the still image decoder, and setting up a restoration form of the 3D still image over a background display.

[12] In accordance with another aspect of the present invention, there is provided a decoding apparatus for a 3D still image service based on DMB, which includes: a still image decoder for recognizing and decoding 3D still image stream through a corresponding object descriptor to thereby produce a 3D still image; and a 3D format converter for setting up a restoration form of the 3D still image outputted from the still image decoder over a background display.

[13] In accordance with another aspect of the present invention, there is provided a method for providing a 3D still image service in a DMB terminal, which includes: checking a broadcasting type of the still image service based on a program information descriptor; when the still image service is a 3D broadcasting service, generating a 3D still image by using reference still image stream and additional still image stream, and displaying the generated 3D still image over a background display; and when the still image service is a 2D broadcasting service, restoring a 2D still image from 2D still image stream and displaying the 2D still image over the background display.

[14] In accordance with another aspect of the present invention, there is provided a method for providing a 3D still image service in a DMB terminal, which includes: checking a broadcasting type of the still image service based on a program information descriptor; when the still image service is a 3D broadcasting service, recognizing and decoding 3D still image stream through a corresponding object descriptor (OD), and restoring the generated 3D still image over a background display; and when the still image service is a 2D broadcasting service, restoring a 2D still image from 2D still image stream and displaying the 2D still image over the background display.

Advantageous Effects

[15] The technology of the present invention described above can provide a user with a three-dimensional (3D) still image through interaction with the user at a specific time and specific video scene, while maintaining compatibility with conventional Digital Multimedia Broadcasting (DMB) services.

[16] Particularly, the technology of the present invention can maximize an advertisement effect by providing a 3D stereoscopic image advertisement service through interaction with a user based on DMB.

[17] Furthermore, the technology of the present invention provides a multiplexing scheme and Moving Picture Experts Group (MPEG) 2 and MPEG 4 system structures that can support both conventional two-dimensional (2D) program and 3D broadcasting program when 2D and 3D programs are arbitrarily serviced. Brief Description of the Drawings

[18] Fig. 1 shows a Program Map Table (PMT) used for conventional DMB services.

[19] Fig. 2 shows how to discriminate between two-dimensional (2D) broadcasting service and three-dimensional (3D) broadcasting service based on a PMT in accordance with an embodiment of the present invention.

[20] Fig. 3 illustrates a multiplexing scheme for providing 3D still image service based on

Digital Multimedia Broadcasting (DMB) in accordance with an embodiment of the present invention.

[21] Figs. 4 and 5 show structures of Moving Picture Experts Group (MPEG) 4 object descriptor (OD) used to describe audio stream, video stream, and still image stream in conventional DMB services.

[22] Figs. 6 and 7 describe a method for representing left/right still image stream by using one object descriptor to provide a 3D still image service in accordance with an embodiment of the present invention.

[23] Figs. 8 and 9 describe a method for representing left/right still image stream by using an object descriptor and an additional descriptor to provide a 3D still image service in accordance with an embodiment of the present invention.

[24] Fig. 10 shows a DMB terminal for providing a DMB-based 3D still image service in accordance with an embodiment of the present invention. Best Mode for Carrying Out the Invention

[25] The advantages, features and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter. When it is considered that detailed description on a related art may obscure a point of the present invention, the description will not be provided herein. Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[26] Fig. 1 shows a Program Map Table (PMT) used for conventional DMB services.

Program Specific Information (PSI) is provided to show a structure of a program and it is composed of Program Association Table (PAT), PMT, Network Information Table (NIT), and Conditional Access Table (CAT). The present invention will be described mainly focusing on the PAT and PMT herein.

[27] Since PAT includes a program number which indicates what programs the transport stream (TS) is formed of and an PMT_PID value corresponding thereto, a system decoder starts providing a program service with the PAT information.

[28] To have a look at the PMT structure shown in Fig. 1, a first descriptor 101 includes a

Moving Picture Experts Group (MPEG) 4 Initial Object Descriptor (IOD). Also, a second descriptor 102 includes Sync Layer (SL) descriptor about media stream and elementary stream (ES) ID.

[29] The initial object descriptor is information that should be transmitted foremost to form a scene, and it describes profile and level of each medium and includes elementary stream IDs of an object descriptor and a Binary Format for Scene (BIFS). An object descriptor is a set of elementary stream descriptors that describe information on each of the media data forming a scene. The object descriptor provides a connection between elementary stream of each media datum and BIFS. Also, BIFS stream shows spatial and temporal position and act of video and audio objects that for a scene.

[30] In short, PMT provides a structure of media data elementary stream that actually forms a program by including the initial object descriptor, which should be transmitted foremost to form a scene, and the PID and descriptors of the media data elementary stream. However, since the PMT structure provided in conventional Digital Multimedia Broadcasting (DMB) services assumes only two-dimensional (2D) broadcasting services, it is required to develop a PMT structure that is suitable for three-dimensional (3D) stereoscopic broadcasting services in future.

[31] Fig. 2 shows how to discriminate between 2D broadcasting service and 3D broadcasting service based on a PMT in accordance with an embodiment of the present invention. The drawing shows a structure of a descriptor for discriminating between 2D still image broadcasting service and 3D still image broadcasting service according to the PMT structure used in the DMB service.

[32] According to the present invention, a DMB -based 3D broadcasting reception terminal recognizes the type of serviced broadcasting through the content defined in Fig. 2.

[33] According to the present invention, a program information descriptor

("Programlnfo_descriptor") 20 in the PMT indicates the broadcasting type of a still image service which is actually broadcasted, that is, it indicates whether it is 2D broadcasting or 3D broadcasting. The "Programlnfo_descriptor" 20 includes "De- scriptor_tag" 201, "Descriptor_length" 202, and "Service format" 203.

[34] The "Programlnfo_descriptor" 20 is disposed right next to an initial object descriptor that comes next to "Program_info_length" in the PMT. When the "Descriptor_tag" 201 is set at "user private" and a receiving part is a conventional 2D DMB terminal, the receiving part cannot analyze it and ignores it. By doing so, the technology of the present invention can keep compatibility with the conventional 2D broadcasting. Herein, the position of the "Programlnfo_descriptor" 20 does not have to be the position right next to the initial object descriptor that comes next to the "Program_info_length" as long as the "Programlnfo_descriptor" 20 comes next to the " Progr am_inf o_length " .

[35] Meanwhile, the "Descriptor_length" 202 indicates the length of a descriptor, and the

"Service format" 203 indicates in the "Programlnfo_descriptor" 20 whether broadcasting is 2D broadcasting or 3D broadcasting and it may be extended diversely.

[36] Fig. 3 illustrates a multiplexing scheme for providing DMB-based 3D still image service in accordance with an embodiment of the present invention. It describes a multiplexing scheme for a case where broadcasting programs related to 2D still image broadcasting service and broadcasting programs related to 3D still image broadcasting service are arbitrarily mingled and provided. In other words, Fig. 3 describes a multiplexing scheme for providing both broadcasting programs related to 2D still image broadcasting service and broadcasting programs related to 3D still image broadcasting service.

[37] A multiplexer of a DMB transmission system receives video elementary stream 301, reference still image elementary stream 302, additional still image elementary stream 303, audio elementary stream 304, and PSI 305, checks the broadcasting type of the still image service (that is, whether it is 2D broadcasting or 3D broadcasting), selects elementary stream related to the broadcasting program according to the broadcasting type, and executes multiplexing as shown in "310" or "320" of Fig. 3. Herein, the broadcasting type can be detected based on broadcasting type information inputted from an operator.

[38] To be specific, in case of 2D broadcasting 310, the multiplexer 30 decides a multiplexing priority order as PSI 305 — > audio elementary stream 304 — > video elementary stream 301 — > reference still image elementary stream (left image) 302 J . In case of 3D broadcasting 320, the multiplexer 30 decides a multiplexing priority order as ^PSI 305 — > audio elementary stream 304 — > video elementary stream 301 — > reference still image elementary stream (left image) 302 — > additional still image elementary stream (right image) 303 J . Then, the multiplexer 30 executes multiplexing according to a transmission period.

[39] Herein, a case where a left image is reference still image has been described as an example but it is also possible to set a right image as a reference still image and a left image as an additional still image. This is true in the following description, too.

[40] Figs. 4 and 5 show structures of MPEG-4 object descriptor used to describe audio stream, video stream, and still image stream in conventional DMB services.

[41] In general DMB, only one object is defined for audio and moving picture video and there may be a plurality of objects for still image which shows information on a specific object and specific scene. In other words, the object descriptors of DMB include one object descriptor for each of audio and video and a plurality of object descriptors for additional data such as still image stream.

[42] Audio stream, moving picture video stream, and still image stream are described using their object descriptors 41, 42, and 43 and elementary stream descriptors 411, 421 and 431, respectively. To be specific, in case of moving picture video stream, "Ob- jectTypeIndication=0x21(AVC)" 412 and "StreamType=0x04(visual stream)" 413 are set up. In case of audio stream, "ObjectTypeIndication=0x40(BSAC)" 422 and "StreamType=0x05 (audio stream)" 423 are set up.

[43] Still image stream is set up with "ObjectTypeIndication=0x6C(jpg)" 432 and

"StreamType=0x04(visual stream)" 433, and the "ObjectTypelndication" may be different according to codec applied thereto. Herein, still image signifies an image that is not treated with a digital video codec standard such as Advanced Video Coding (AVC), and visual still image includes visual images of diverse formats, such as Joint Photographic Experts Group (JPG), Portable Network Graphics (PNG), Graphics Interchange Format (GIF), and Multiple Network Graphics (MNG).

[44] Meanwhile, the object descriptor identification (0D_ID) has a unique value for each of the audio stream, the video stream, and still image stream. For example, the audio stream has a value of 10; the video stream, 20; and the still image stream, 30. The value is the same as the position information of each node, e.g., Uniform Resource Locator (URL) value, described in BIFS. In short, BIFS includes an "AudioSource" node, a "Movie Texture" node, and an "ImageTexture" node to represent the audio stream, the moving picture video stream, and still image stream, and the nodes are related to the respective object descriptor IDs (0D_ID).

[45] The present invention provides an MPEG-4 object descriptor structure for 3D stereoscopic image advertisement while maintaining compatibility with conventional DMB by using the "ImageTexture" node and the related object descriptor structure for representing still image stream in the conventional MPEG-4 Object Descriptor/BIFS basic structure, which is used in DMB services. This will be described by referring to Figs. 6 to 9.

[46] Figs. 6 and 7 describe a method for representing left/right still image stream by using one object descriptor to provide a 3D still image service in accordance with an embodiment of the present invention. The drawings show how to represent left/right still image stream outputted to a codec in a master-and-slave relationship by using one object descriptor. [47] Referring to Figs. 6 and 7, two elementary stream descriptors (ESDs) 511 and 512 for the left/right still image streams are defined under one object descriptor 51, and the two elementary stream descriptors 511 and 512 has a master and slave relationship. Herein, the master and slave relationship can be represented using "StreamDepen- danceFlag" and "dependsOn_ES_ID" of an MPEG-4 elementary stream descriptor.

[48] 'Reference still image (left image)' 51 is independent stream, and it is represented using "ImageTexture" node which is used to represent still image stream in a conventional DMB service. That is, the "Reference still image (left image)" 51 is set as "ObjectTypeIndication=0x6C(jpg), StreamType=0x04(visual stream)"

[49] Meanwhile, 'additional still image (right image)' 512 is dependent stream, and it is set as "ObjectTypeIndication=0xC0(user private), StreamType=0x04(visual stream) StreamDependanceFlag=l, DependsOn_ES_ID=30 preference still image ES_ID)" under an object descriptor for 'reference still image (left image)'. In short, the values of "ObjectTypelndication" and "StreamType" for additional still image (right image) are set the same as the reference still image (left image).

[50] When a broadcast transmitting part transmits broadcast representing still image in the above-described method, a conventional 2D DMB terminal cannot recognize the "ObjectTypelndication" information for additional still image stream, and after all the additional still image stream is abandoned. In other words, the conventional DMB terminal recognizes only reference still image stream and thus provides only 2D sill image service.

[51] The present invention described above has the same structure as an object descriptor used to represent one still image object in the conventional DMB service as it recognizes 3D object as one object and includes one 0D_ID within BIFS. Therefore, the present invention is advantageous in that it can apply the conventional method to reference still image without any change.

[52] The DMB terminal of the present invention that can service left/right still image stream in accordance with an embodiment of the present invention shown in Fig. 7 can receive and decode reference still image stream and additional still image stream, which are included in one object descriptor in an independent/dependent form.

[53] As illustrated in Figs. 6 and 7, the present invention which represents the 'additional still image (right image)' 512 as dependent stream on the 'reference still image (left image)' 51 makes a user enjoy a specific scene or a specific object in three-dimensional. Also, when still image streams are formed as a slide show, the present invention can be applied as a 3D stereoscopic advertisement on a video channel.

[54] Figs. 8 and 9 describe a method for representing left/right still image stream by using an object descriptor and an additional descriptor to provide a 3D still image service in accordance with an embodiment of the present invention. The drawings show a method of representing reference image stream (left still image stream) outputted to a codec by using one object descriptor and additional still image stream (right still image stream) by using an additional descriptor, which is independent from the object descriptor.

[55] The reference still image (left image) stream is independent stream and it is set as

"ObjectTypeIndication=0x6C(jpg), StreamType=0x04(visual stream)" under one object descriptor 61 by using "ImageTexture" node for representing still image stream in a DMB service. In short, reference still image (left image) stream is represented using one object descriptor 61.

[56] Meanwhile, additional still image (right image) stream is additional stream for representing a 3D scene, and it is represented using a separate additional descriptor (AD) 62. In short, additional still image (right image) stream is represented using "ObjectDe- pendanceFlag" and "DependsOn_OD_ID" of the additional descriptor 62.

[57] To be specific, the additional still image (right image) stream is set as "Object-

TypeIndication=0x6C(jpg), StreamType=0x04(visual stream) ODDependanceFlag=l, dependsOn_OD_ID=30(reference still image 0D_ID" under one additional descriptor for the 3D still image service. Herein, the values of "ObjectTypelndication" and "StreamType" are set the same as the reference still image (left image).

[58] Also, the transmitting part sets additional descriptor tag (AD_Descriptor Tag) as

"User private" in the present invention. Then, the conventional DMB terminal, which is the receiving part, cannot recognize the additional descriptor for the additional still image (right image) stream and after all, the additional still image (right image) stream is abandoned. However, the conventional DMB terminal can restore reference still image stream described wit one 0D_ID within BIFS. Therefore, the present invention can maintain compatibility with conventional DMB specification.

[59] Figs. 6 to 9 describe the method of describing an object for the reference still image and additional still image in such a manner that the receiving part generates a 3D still image. According to another embodiment of the present invention, it is possible for the transmitting part to set pre-generated 3D still image (which is a 3D still image produced by combining a reference still image and an additional still image) as independent stream by using one object descriptor. Herein, the 3D still image is not compatible with conventional DMB terminals and it can be provided only as a sort of premium service which is available only in the DMB terminals for a 3D still image service. This is possible by setting "ObjectTypeIndication=user private" under one object descriptor.

[60] Fig. 10 shows a DMB terminal for providing a DMB-based 3D still image service in accordance with an embodiment of the present invention. The drawing shows a DMB terminal for providing a BIFS-based 3D still image service by using the structure of object descriptor illustrated in Figs. 6 to 9. Hereinafter, a 3D still image service providing method executed in a DMB terminal will be described.

[61] The DMB terminal of the present invention includes a decoder 71 and a restoration processor 72. As shown in Fig. 7, the decoder 71 includes a video decoder 711, a still image decoder 712, and a 3D format converter 713.

[62] The video decoder 711 recognizes and decodes the video elementary stream (which is moving picture elementary stream) through the object descriptor for the video. The moving picture over which a still image is to be restored, which is a background, is moving picture transmitted through a broadcasting network generally, but the present invention is not limited to it according to embodiments. The background may be moving picture acquired through diverse acquisition channels, such as a recording medium (e.g., CD), a wireless internet, and a broadcasting network of another channel and restored.

[63] The still image decoder 712 separately recognizes and decodes reference still image elementary stream and additional still image elementary stream by using "one object descriptor" (see Figs. 6 and 7) or "one object descriptor and one additional descriptor" (see Figs. 8 and 9) according to an embodiment.

[64] The 3D format converter 713 provides serviced still images in 2D or 3D according to a restoration mode, which is a 2D restoration mode or a 3D restoration mode, inputted from a user. This will be described in detail hereafter. Herein, it is assumed that the restoration mode is a mode indicating whether a still image is 2D or 3D.

[65] First, when the restoration mode is a 3D restoration mode, the 3D format converter

713 generates a 3D still image by using the left/right still images decoded in the still image decoder 712 and sets up a restoration form, such as restoration position of the 3D still image and display size, of the 3D still image when the 3D still image is represented (which means restored) on the display of the 2D/3D moving picture obtained from decoding in the video decoder 711 (see 723 to 725).

[66] Herein, the 3D format converter 713 generates a 3D still image by interleaving the left/right still images according to an applied 3D display method. In other words, any one between the reference still image and additional still image decoded in the still image decoder 712 is converted into an image having only odd- line data, and the other is converted into an image having only even-line data. Then, the odd-line data are interleaved with the even-line data to thereby generate the 3D still image. The method of generating one 3D still image by using left/right still images includes diverse conventional 3D video generating methods.

[67] The moving picture to be a background, which is a background display, on which a

3D still image (for example, an advertisement image) is to be represented may be 2D moving picture or 3D moving picture. To be specific, the 3D format converter 713 may magnify 2D moving picture which is decoded in a video decoder into a size supported by a display device and use the magnified 2D moving picture (see 722) or the 3D format converter 713 may take the original 2D moving picture as a left image, create a right image by copying the left image, and interleave the left image with the right image to thereby generate a 3D moving picture (see 723).

[68] The 3D format converter 713 sets up the restoration form of a 3D still image as follows. That is, the 3D format converter 713 represents a 3D still image over a moving picture by positioning the 3D still image at a specific part (see 723 and 724) or the entire display (see 725) of the 2D moving picture.

[69] Meanwhile, the restoration processor 72 restores moving picture and 2D or 3D still image outputted from the 3D format converter 713. The types of restoration are diverse (see 721 to 725). In short, the restoration processor 72 uses diverse methods such as overlapping a still image over a background moving picture.

[70] When the restoration mode inputted from a user is 2D restoration mode, the 3D format converter 713 disregards additional still image and outputs only reference still image to the restoration processor 72 without any format conversion. Then, the restoration processor 72 restores a 2D still image, which is the reference still image, over the moving picture (see 721 and 722). In this case, too, the 3D format converter 713 sets up the 'restoration form' upon receipt of a user's request to restore the reference still image, which is left image, on the specific part (see 721) or the entire display (see 722) of the 2D or 3D moving picture. The 3D format converter can also create 3D moving picture from the 2D moving picture and outputs the created 3D moving picture to the restoration processor 72, thereby representing the 2D reference still image over 3D moving picture.

[71] Although the transmitting part defines the still image service as 3D broadcasting service and accordingly both reference still image and additional still image are transmitted together, if the user selects the 2D restoration mode in the DMB terminal, the 2D still image service is provided to the user.

[72] Meanwhile, when the transmitting part does not transmit both reference still image and additional still image but transmits '3D still image' itself, the still image decoder 712 of the DMB terminal of the present invention recognizes and decodes 3D still image stream through the object descriptor. Then, the 3D format converter 713 combines the reference still image with additional still image to thereby set up the restoration form of 3D still image over the background of moving picture, instead of generating 3D still image, which is described above.

[73] It is possible to check whether the still image service that the DMB terminal of Fig. 7 receives from the transmitting part is 2D broadcasting or 3D broadcasting according to an embodiment, which is not illustrated in Fig. 7. Herein, the broadcasting type is checked out based on a program information descriptor (Programlnfo_descriptor) in the PMT. If the broadcasting type is 3D broadcasting, the DMB terminal restores 2D or 3D still image according to the restoration mode of the user as described above. If the broadcasting type is 2D broadcasting, the DMB terminal recognizes and decodes still image stream through a corresponding object descriptor and restores the decoded still image over moving picture.

[74] As described above, the method of the present invention can be realized as a program and stored in a computer-readable recording medium, such as CD-ROM, RAM, ROM, floppy disks, hard disks, magneto-optical disks and so forth. Since this process is widely known to those skilled in the art to which the present invention pertains, further description will not be provided herein.

[75] The present application contains subject matter related to Korean Patent Application

No. 2007-0052158, filed in the Korean Intellectual Property Office on May 29, 2007, the entire contents of which is incorporated herein by reference.

[76] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

Claims

[1] A method for describing an object to provide a three-dimensional (3D) still image service based on Digital Multimedia Broadcasting (DMB), comprising: deciding a broadcasting type of a still image service to be broadcasted between two-dimensional (2D) broadcasting and 3D broadcasting based on a program information descriptor (Programlnfo_descriptor) in a Program Map Table (PMT); and describing reference still image and additional still image that are transmitted separately for the 3D still image service with relation to each other.

[2] The method of claim 1, wherein the reference still image and the additional still image are described using one object descriptor (OD), and the reference still image is set up to be independent stream while the additional still image is set up to be dependent stream.

[3] The method of claim 2, wherein elementary stream descriptor (ESD) for the reference still image and the elementary stream descriptor for the additional still image are formed in a master-and-slave relationship by using the same object descriptor.

[4] The method of claim 1, wherein the reference still image is set up to be independent stream by using one object descriptor, and the additional still image is set up to be independent stream by using an additional descriptor related to the object descriptor.

[5] The method of claim 4, wherein the additional descriptor of the additional still image is set up to be subordinate to the object descriptor of the reference still image.

[6] The method of claim 1, wherein the broadcasting type is set up using the program information descriptor in a PMT.

[7] A method for describing an object to provide a three-dimensional (3D) still image service based on Digital Multimedia Broadcasting (DMB), comprising: deciding a broadcasting type of a still image service to be broadcasted between two-dimensional (2D) broadcasting and 3D broadcasting based on a program information descriptor (Programlnfo_descriptor); and setting up 3D still image to be serviced as independent stream by using one object descriptor.

[8] The method of claim 7, wherein the broadcasting type is set up using the program information descriptor in a Program Map Table (PMT).

[9] A multiplexing method for a three-dimensional (3D) still image service based on

Digital Multimedia Broadcasting (DMB), comprising: receiving elementary streams for broadcasting programs; checking whether a broadcasting type of a still image service related to a broadcasting program to be broadcasted is two-dimensional (2D) broadcasting or 3D broadcasting; and selecting elementary streams related to the broadcasting program whose broadcasting type is confirmed among the inputted elementary streams and multiplexing the selected elementary streams based on a corresponding multiplexing priority order.

[10] The multiplexing method of claim 9, wherein the priority order is Program

Specific Information (PSI) sequentially followed by audio stream, video stream, and reference still image for a 2D broadcasting program, whereas the priority order is PSI sequentially followed by audio stream, video stream, reference still image, and additional still image stream for a 3D broadcasting program.

[11] A decoding apparatus for a three-dimensional (3D) still image service based on

Digital Multimedia Broadcasting (DMB), comprising: a still image decoder for individually recognizing and decoding reference still image stream and additional still image stream to thereby produce reference still image and additional still image; and a 3D format converter for generating a 3D still image by combining the reference still image and the additional still image that are obtained in the still image decoder, and setting up a restoration form of the 3D still image over a background display.

[12] The decoding apparatus of claim 11, wherein the still image decoder individually recognizes and decodes the reference still image stream and the additional still image stream through one object descriptor.

[13] The decoding apparatus of claim 11, wherein the still image decoder recognizes the reference still image stream through an object descriptor and the additional still image stream through a separate additional object descriptor, and individually decodes the reference still image stream and the additional still image stream.

[14] The decoding apparatus of claim 11, wherein when a 2D still image restoration mode is selected by a user, the 3D format converter does not generate a 3D still image and transmits the reference still image obtained in the still image decoder to a restoration processor after setting up a restoration form of the reference still image according to a request from a user.

[15] The decoding apparatus of claim 11, wherein the 3D format converter sets up a restoration position and size of the 3D still image to be restored over a background display.

[16] A decoding apparatus for a three-dimensional (3D) still image service based on

Digital Multimedia Broadcasting (DMB), comprising: a still image decoder for recognizing and decoding 3D still image stream through a corresponding object descriptor (OD) to thereby produce a 3D still image; and a 3D format converter for setting up a restoration form of the 3D still image outputted from the still image decoder over a background display.

[17] The decoding apparatus of claim 16, wherein the 3D format converter sets up a restoration position and size of the 3D still image to be restored over a background display.

[18] A method for providing a three-dimensional (3D) still image service in a Digital

Multimedia Broadcasting (DMB) terminal, comprising: checking a broadcasting type of the still image service based on a program information descriptor; when the still image service is a 3D broadcasting service, generating a 3D still image by using reference still image stream and additional still image stream, and displaying the generated 3D still image over a background display; and when the still image service is a 2D broadcasting service, restoring a 2D still image from 2D still image stream and displaying the 2D still image over the background display.

[19] The method of claim 18, wherein said generating a 3D still image by using reference still image stream and additional still image stream, and restoring the generated 3D still image over a background display includes: recognizing and individually decoding the reference still image stream and the additional still image stream through one object descriptor (OD) to thereby produce reference still image and additional still image; generating the 3D still image by combining the reference still image and the additional still image that are obtained from the decoding; and displaying the generated 3D still image over the background display.

[20] The method of claim 18, wherein in said generating a 3D still image by using reference still image stream and additional still image stream, and restoring the generated 3D still image over a background display includes: recognizing the reference still image stream through an object descriptor and the additional still image stream through an additional descriptor (AD), and individually decoding the reference still image stream and the additional still image stream to thereby produce reference still image and additional still image; generating the 3D still image by combining the reference still image and the additional still image obtained from the decoding; and displaying the generated 3D still image over a background display.

[21] The method of claim 18, wherein the program information descriptor is set up in a Program Map Table (PMT).

[22] A method for providing a three-dimensional (3D) still image service in a Digital

Multimedia Broadcasting (DMB) terminal, comprising: checking a broadcasting type of the still image service based on a program information descriptor; when the still image service is a 3D broadcasting service, recognizing and decoding 3D still image stream through a corresponding object descriptor (OD), and restoring the generated 3D still image over a background display; and when the still image service is a 2D broadcasting service, restoring a 2D still image from 2D still image stream and displaying the 2D still image over the background display.

[23] The method of claim 22, wherein the program information descriptor is set up in a Program Map Table (PMT).