USRE39367E

Method for encoding and decoding moving picture signals

Claim Score by NHIP

Abstract

A method for encoding and decoding digital moving picture signals which can decode subframes appropriately in relation to time if a part of a bit stream is missing or an error occurs in the bit stream, and can suppress degradation of a reproduced picture if decoding of a subframe including a picture in motion in relation to time becomes unfeasible. In the method for encoding and decoding digital moving picture signals of this invention, information for one frame is encoded correspondingly to a spatial hierarchy of a frame, subframes and blocks. A subframe time position number and a subframe space number are attached to an identifier of each of the subframe, thereby resuming appropriate decoding of the subframes immediately after a trouble if an error occurs. The subframe identifiers are placed at a certain interval in the bit stream so as to give a smaller size to a subframe including a block which is in motion and difficult to be encoded, thereby suppressing degradation of a reproduced picture if decoding of the subframe becomes unfeasible.

Term

Term ended

Expired 31 January 2016, 10.6 years ago.

21 claims: 9 independent, 12 dependent

1
A method for encoding digital motion picture signals of a frame, comprising the steps of:dividing said frame into plural blocks each including N×M pixels;forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;setting an identifier to said subframe to identify said subframe;and specifying a frame to which said subframe belongs by adding to said identifier time position information to said identifier representing an order of displaying said subframe;encoding said time position information along with said subframe, and multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream.
2
Broadest claimClaim Score 79, broad(NHIP)A method for encoding digital motion picture signals of a frame, comprising the steps of:dividing said frame into plural blocks each including N×M pixels;forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;and varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame.
3
A method for encoding digital motion picture signals of a frame, comprising the steps of:dividing said frame into plural blocks each including N×M pixels. forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;setting an identifier to said subframe to identify said subframe;specifying a frame to which said subframe belongs by adding to said identifier time position information representing an order of displaying said subframe;encoding said time position information along with said subframe, and multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream;and varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame.
6
A method for encoding and decoding digital motion picture signals of a frame, comprising the steps of:dividing said frame into plural blocks each including N×M pixels;forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;setting an identifier to said subframe to identify said subframe;specifying a frame to which said subframe belongs by adding to said identifier time position information representing an order of displaying said subframe;encoding said time position information along with said subframe;multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream;and decoding each of said subframes appropriately in relation to time by decoding and using said time position information to form said frame of said digital moving picture signals.
7
A method for encoding and decoding digital motion picture signals of a frame, comprising the steps of:dividing said frame into plural blocks each including N×M pixels;forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame;and decoding each of said subframes to form said frame of said digital moving picture signal.
8
A method for encoding and decoding digital motion picture signals of a frame, comprising the steps of:dividing said frame into plural blocks each including N×M pixels;forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded, setting an identifier to said subframe to identify said subframe;specifying a frame to which said subframe belongs by adding to said identifier time position information representing an order of displaying said subframe;encoding said time position information along with said subframe;multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream;varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame;and decoding said subframe appropriately in relation to time by decoding and using said time position information to form said frame of said digital moving picture signal.
17
A method for encoding digital motion picture signals of a frame, comprising:dividing said frame into plural blocks each including N×M pixels;forming a subframe composed of at least one of said blocks, said subframe being a unit to be encoded;setting an identifier to said subframe to identify said subframe;specifying a frame to which said subframe belongs by adding time position information to said identifier, the time position information representing an order of displaying said subframe;specifying a spatial position of said subframe within said frame by adding spatial position information to said identifier, the spatial position information representing said spatial position of said subframe within said frame;encoding said time position information and said spatial position information along with said subframe, and multiplexing said encoded time position information, said encoded spatial position information and a bit stream of said encoded subframe to transmit said encoded spatial position information, said encoded time position information and said bit stream.
18
A method for encoding and decoding digital motion picture signals of a frame, said method comprising:dividing said frame into plural blocks each including N×M pixels;forming a subframe composed of at least one of said blocks, said subframe being a unit to be encoded;setting an identifier to said subframe to identify said sub - frame;specifying a frame to which said subframe belongs by adding time position information to said identifier, the time position information representing an order of displaying said subframe;specifying a spatial position of said subframe within said frame by adding spatial position information to said identifier, the spatial position information representing said spatial position of said subframe within said frame;encoding said time position information and said spatial position information along with said subframe;multiplexing said encoded time position information, said encoded spatial position information and said encoded subframe to transmit said encoded spatial position information, said encoded time position information and said encoded subframe as an encoded bitstream;receiving said encoded bitstream;detecting said identifier to extract said encoded time position information and said encoded spatial position information from said encoded bitstream;decoding said extracted encoded time position information to obtain decoded time position information;decoding said extracted encoded spatial position information to obtain decoded spatial position information;and decoding said encoded subframe to form said frame according to said decoded spatial position information and said decoded time position information.
19
A method for decoding an encoded bitstream, said method comprising:( a ) receiving said encoded bitstream containing an identifier, an encoded subframe obtained by encoding a subframe composed of at least one of said blocks, and an encoded spatial position information representing a spatial position of said subframe within a frame composed of a plurality of subframes and an encoded time position information representing an order of displaying said subframe, wherein said identifier is set to said encoded subframe to identify said subframe, said encoded time position information is added to said identifier by specifying a frame to which said subframe belongs, and said encoded spatial position information is added to said identifier by specifying a spatial position of said subframe within said frame;( b ) detecting said identifier to extract said encoded spatial position information and said encoded time position information from said encoded bitstream;( c ) decoding said extracted encoded time position information to obtain decoded time position information;( d ) decoding said extracted encoded spatial position information to obtain decoded spatial position information;and ( e ) decoding said encoded subframe to form said frame according to said decoded spatial position information and said decoded time position information.

Independent claims9

87 paragraphs in 4 sections, as filed

0001This application is a continuation of Reissue Application Ser. No. 09/925,423, filed Aug. 10, 2001.

0002Notice: more than one reissue application has been filed for the reissue of U.S. Pat. No. 5,937,095. The reissue applications are the present reissue application Ser. No. 10/662,949 filed on Sep. 16, 2003, and related reissue application Ser. Nos., 11/108,884 filed on Apr. 19, 2005, 11/108,883 filed on Apr. 19, 2005 and 11/108,885 filed on Apr. 19, 2005, and the original reissue application Ser. No. 09/925,423, filed Aug. 10, 2001, now U.S. Pat. No. Re. 38,726. The present reissue application and the related reissue applications are all continuation applications of application Ser. No. 09/925,423.

BACKGROUND OF THE INVENTION

0003(1) Field of the Invention

0004The present invention relates to a method for encoding and decoding digital moving picture signals for use in TV phones, TV conferences and the like.

0005(2) Description of the Prior Art

0006In a general method for encoding digital moving picture signals, a frame of inputted moving picture is divided into plural blocks each composed of N×M pixels, and processes of motion detection, prediction, orthogonal transform, quantization, variable length coding, etc. are conducted on each block.

0007In a general method for decoding digital motion picture signals, blocks each composed of N×M pixels are regenerated in a reverse procdyreprocedure, that is, processes of variable length decoding, reverse quantization, reverse orthogonal transform, motion compensation, etc.

0008The above general encoding method and decoding method for encoding and decoding digital moving picture signals enable removal of redundancy contained in moving picture signals, and efficient communication and storage of a moving picture with less information.

0009In the general encoding method and decoding method for encoding and decoding digital moving picture signals, the processes are conducted on each pixel block, as stated above. It is general that a set of pixel blocks forms a subframe and a set of subframes forms a frame, which are units processed in the general encoding and decoding method.

0010Hereinafter, encoding and decoding of each block, subframe and frame will be described by way of an example of a general encoding and decoding method for encoding and decoding digital moving picture signals with reference to ITU-T Recommendation H.261 (hereinafter, referred simply H.261) made on March, 1993.

0011H.261 defines an encoding method and a decoding method for encoding and decoding luminance signals and color difference signals, separately, of digital moving picture signals. However, description will be made of only the luminance signals, for the sake of convenience. Basically, the encoding method and decoding method for encoding and decoding the luminance signals are not different from those for the color difference signals.

0012As shown in <figref idref="DRAWINGS">FIG. 1</figref>, one frame 101 of digital moving picture signals is composed of 352×288 pixels according to H.261. The frame 101 is divided into twelve subframes 102 called GOBs (Group of Blocks) each composed of 176×48 pixels (hereinafter, the subframe in the description of the prior art will be referred a GOB). Further, the GOB 102 (subframe) is divided into thirty three blocks 103 called macro blocks each composed of 16×16 pixels.

0013The encoding method according to H.261 defines that encoded information for one frame is corresponded to a spatial hierarchical structure such as the frame 101, GOBs 102 and macro blocks 103 described above, as shown in FIG. 2.

0014In <figref idref="DRAWINGS">FIG. 2</figref>, a part enclosed in a rectangle shows encoded information, and the number of coding bits is shown under each of the rectangles. In <figref idref="DRAWINGS">FIG. 2</figref>, arrows show linkages of the encoded information. A series of encoded moving picture signal sequences as this is called a bit stream 104.

0015In the bit stream 104 according to H.261 shown in <figref idref="DRAWINGS">FIG. 2</figref>, a part including all encoded information for one macro block 103 is called a macro block layer 103S, a part including all encoded information for one GOB 102 is called a GOB layer 102S, and a part including all encoded information for one frame 101 is called a frame layer 101S.

0016Meanings of the encoded information in each of the layers shown in FIG 2 are given below:

0000Frame Layer 101S

0017PSC (20 bits): a frame identifier 105; a unique code by which an encoding method can be always identified, expressed as “0000 0000 0000 0000 0001”;

0018TR (5 bits): a frame number 106; indicating a time position in which this frame 101 should be displayed;

0019PTYPE (6 bits): frame type information 107; various information about the frame 101;

0020PEI (1 bit): extension data insertion information 108; a flag representing presence of following PSPARE 109;

0021PSPARE (8 bits): extension data; GOB layer 102S (subframe)

0022GBSC (16 bits): a GOB identifier 110; a unique code by which a decoding method can be always identified, expressed as “0000 0000 0000 0000”;

0023GN (4 bits): a GOB number 111; indicating a spatial position of this GOB 102 within the frame 101;

0024GQUANT (5 bits): quantization characteristic information 112; indicating a quantization characteristic when a macro block 103 in the GOB 102 is encoded;

0025GEI (1 bit): extension data insertion information 113; a flag representing presence of following GSPARE 114;

0026GSPARE (8 bits): extension data 114.

0027Incidentally, the encoded information 115 of the macro block layer which is the lowest hierarchy in <figref idref="DRAWINGS">FIG. 2</figref> is generated in the encoding method of motion detection, prediction, orthogonal transform, quantization, variable length coding, etc., as described before, whose coding bit number is not fixed. The number of coding bits of the macro block layer 103S, in general, increases if a spatial level of pixels included in the macro block 103 changes largely or a time level of pixels included in the macro block 103 having the same spatial positions changes largely. Such macro block 103 is, hereinafter, referred a macro block 103 which is difficult to be encoded.

0028To the contrary, if a level of pixels included in the macro block 103 is steady in relation to space and time, the number of coding bits of the macro block layer 103S remarkably decreases, or sometimes becomes zero. Such macro block 103 is hereinafter referred a macro block 103 which is easy to be encoded.

0029In the decoding method according to H.261, the PSC 105 which is an identifier of the frame layer 101S is first found out from the bit stream 104. Incidentally, in a state where a decodable code has been successfully found out it is said that synchronization is established. When the PSC 105 is found out from the bit stream and synchronization of the frame layer 101S is established, it can be identified that the bit stream 104 until the next PSC 105 appears is encoded information for one frame. Further, a time position in which the frame 101 composed of 352×288 pixels obtained by decoding the bit stream 104 for that one frame can be obtained by examining the frame number 106 following the PSC 105.

0030After the establishment of the frame layer, a GBSC 110 that is an identifier of the GOB layer 102S is found out from the following bit stream 104 in the encoding method according to H.261. When synchronization of the GBSC layer is established, it can be identified that the bit stream 104 until the next GBSC 110 appears is encoded information for one GOB 102. Further, a spatial position of the GOB 102 composed of 176×48 pixels obtained by decoding the bit stream 104 for that one GOB 102 in a frame 101, in which the GOB 102 should be placed, can be obtained by examining a GN 111 which is a GOB number following the GBSC 110.

0031In the decoding method according to H.261, a bit stream 104 of a following macro block layer 103S is decoded after the establishment of the GOB layer 102s. The decoding method of the macro block layer 103S is a procedure to regenerate a macro block 103 composed of 16×16 pixels in processes of variable length decoding, reverse quantization, reverse orthogonal transform, motion compensation, etc., as described before. It should be here noted that the macro block layer 103S has no unique code by which a decoding method can be always identified dissimilarly to the PSC 105 or BGSC 110, and encoded information of each macro block is composed of undefined length bits of a variable length code.

0032As shown in <figref idref="DRAWINGS">FIG. 3</figref>, in the GOB (subframe) layer 102S, the encoded information from the first macro block 115, to the thirty third macro block 11533 is expressed as a series of variable length codes without a unique code. If decoding of the macro block encoded information is initiated from a point indicated by A in <figref idref="DRAWINGS">FIG. 3</figref>, and successively conducted in the order of the first, the second, . . . the nth, . . . the thirty third macro blocks, it is possible to regenerate all the macro blocks 103 in the GOB layer 102S. However, if the decoding of the macro block encoded information is initiated from a point indicated by B or C in <figref idref="DRAWINGS">FIG. 3</figref>, it is impossible to identify a point from which encoded information 115 of one macro block starts, which leads to a failure of establishing synchronization. In which case, the decoding and regenerating all macro blocks 103 become unfeasible until the next GBSC 110 appears. In other words, the GBSC 110 also represents a starting point of decoding the macro block layer 103S.

0033Finally, in the decoding method according to H.261, the GOB 102 which is a set of regenerated macro blocks 103 is placed in a spatial position within a frame 101 directed by GN 111, and the frame 100 which is a set of the regenerated GOBs 102 is placed in a time position directed by TR 106.

0034As above, it is possible to decode one frame 101 of digital moving picture correctly in relation to space and time according to H.261.

0035However, the above general method for encoding and decoding digital moving picture signals has a drawback that if a part of a bit stream 104lacksis lacking or an error occurs therein, it might be impossible to accurately decode all subframes (GOBs) 102 in relation to time until synchronization of the next frame layer 101S is established.

0036The reason of the above is that codes which can be identified at all times in the bit stream 104 are only the PSC 105 which is a frame identifier and the GBSC 110 which is a subframe identifier in the general decoding method. If a part of the bit stream 104 lacks or an error occurs therein, it is impossible to recover synchronization of the decoding until the next GBSC 110 appears so that the decoding becomes unfeasible. Even if the next GBSC 110 appears, the bit stream 104 of that subframe layer 102S cannot be correctly decoded in relation to time. This will be understood from FIG. 4.

0037<figref idref="DRAWINGS">FIG. 4</figref> shows an example where the fifth GOB 1025 in the nth frame 101n through the sixth GOB 1026 in the (n+1)th frame 101n−1101n+1cannot be decoded in relation to time due to lackslacking portions or errors of the bit stream 104 occurring in burst. In this example, not only the PSC 105 corresponding to the (n+1)th frame in relation to time but also the following TR 106 are missed or in error. It is therefore possible to correctly decode the GOB 1027 in relation to space by establishing synchronization from the GBSC 110 corresponding to the seventh GOB 1027 in the (n+1)th frame 101n+1 in relation to time and decoding the following GN 111, but impossible to specify whether this GOB 1027 positions in the nth frame or in the (n+1)th frame in relation to time.

0038In terms of decoding of the eighth GOB 1028 through the twelfth GOB 10212 in the (n+1)th frame in relation to time, it is impossible to specify whether these GOBs 102 position in the nth frame or in the (n+1)th frame in relation to time.

0039In consequence, if a part of the bit stream 104 is missedmissing or an error occurs therein, it becomes impossible to correctly decode all GOBs 102 in relation to time until synchronization of the next frame layer 1015 is established.

0040Further, the general method for encoding and decoding digital moving picture signals has another drawback that if the GOB 102 including a picture in motion in relation to time cannot be decoded, a picture quality of the reproduced picture is largely degraded.

0041This problem will be described in more detail with reference to FIG. 5. FIG 5 shows one frame including decoded signals of a moving picture, where a figure is moving in the center of the frame. In <figref idref="DRAWINGS">FIG. 5</figref>, a part moving in relation to time is indicated by slanting lines, and the remaining part is a background which is still in relation to time. A scene like this is general in TV conferences, TV telephones or the like.

0042Referring to <figref idref="DRAWINGS">FIG. 5</figref>, considering that any one of the first GOB 1021 through the fourth GOB 1024 cannot be decoded. The first through fourth GOBs 1021 through 1024 include a picture still in relation to time. If the second GOB 1022 cannot be decoded, for example, a skillful operation is conducted to substitute the second GOB 1022 of the present frame 101 with the second GOB 1022 of the preceding frame 101−1 in the decoding. With this operation, degradation of a picture quality in the second GOB 1022 of the present frame 101 may be hardly detected.

0043However, it is a problem if decoding on the fifth through twelfth GOBs 1025 through 10212 shown in <figref idref="DRAWINGS">FIG. 5</figref> cannot be decoded. The fifth through twelfth GOSsGOBs 1025 through 10212 include a picture moving in relation to time. This means, for example, that a picture in the ninth GOB 1029 of the preceding frame 101−1 is largely different from the ninth GOB 1029 of the present frame 101 in relation to time. If the decoding of the ninth GOB 1029 is unfeasible, degradation of the picture quality of the ninth GOB 1029 of the present frame 101 is obviously detected even if the skillful operation mentioned above is conducted in the decoding.

0044Accordingly, if decoding of GOB 102 including a picture moving in relation to time becomes unfeasible, a quality of a reproduced picture is largely degraded.

SUMMARY OF THE INVENTION

0045In the light of the above problems, an object of the present invention is to provide a method for encoding and decoding digital moving picture signals, which can appropriately decode subframes (GOBs) following a subframe in trouble in relation to time if a part of a bit stream is missing or an error occurs in the bit stream.

0046Another object of the present invention is to provide a method for encoding and decoding digital moving picture signals, which can suppress degradation of a reproduced picture to a small extent if decoding of a subframe (GOB) including a picture in motion in relation to time becomes unfeasible.

0047To accomplish the first object, the present invention is featured in that in the method for encoding and decoding digital moving picture signals of this invention, time position information representing an order of displaying a subframe is attached to an identifier of the subframe by which the subframe is identified.

0048According to the method for encoding and decoding digital moving picture signals of this invention, time position information representing an order of displaying a subframe is attached to an identifier used to identify the subframe and the identifier of the subframe is encoded. It is therefore possible to decode subframes following a subframe in trouble appropriately in relation to time if a part of bit streama bit stream is missing or an error occurs in the bit stream by using the time position information representing an order of displaying each of the subframes attached to an identifier used to identify the subframe.

0049To accomplish the second object, the present invention is featured in that in the method for encoding and decoding digital moving picture signals of this invention, the number of blocks included in a subframe is varied according to a sum of quantities of generated information of the blocks included in the subframe so that each of all the subframes included in the frame has an equal sum of quantities of the generated information of the blocks included in the subframe.

0050According to the method for encoding and decoding digital moving picture signals of this invention, the number of blocks included in a subframe is varied according to a sum of quantities of generated information of the blocks included in the subframe so that each of all the subframes included in the frame has an equal sum of quantities of the generated information of the blocks included in the subframe. In consequence, a spatial size of each subframe is not fixed. A subframe including a block having a large number of coding bits is in a smaller size, whereas a subframe including a block having a small number of coding bits is in a larger size. It is therefore possible to suppress degradation of a reproduced picture even if decoding of a subframe becomes unfeasible since a subframe including a block which includes a motion in relation to time and is difficult to be encoded is in a smaller size in relation to space.

BRIEF DESCRIPTION OF THE DRAWINGS

0051<figref idref="DRAWINGS">FIG. 1</figref> shows units to be encoded in a general encoding method for encoding moving picture signals;

0052<figref idref="DRAWINGS">FIG. 2</figref> shows a bit stream generated in the general encoding method for encoding moving picture signals;

0053<figref idref="DRAWINGS">FIG. 3</figref> shows a GOB layer in the bit stream in <figref idref="DRAWINGS">FIG. 2</figref> generated in the general encoding method for encoding moving picture signals;

0054<figref idref="DRAWINGS">FIG. 4</figref> illustrates an effect of a lack or an error of a part of a bit stream occurring in the general encoding and decoding method for encoding and decoding moving picture signals;

0055<figref idref="DRAWINGS">FIG. 5</figref> illustrates an effect of a lack or an error of a part of a bit stream occurring in the general encoding and decoding method for encoding and decoding moving picture signals;

0056<figref idref="DRAWINGS">FIG. 6</figref> shows a bit stream generated in a method for encoding digital moving picture signals according to first and second embodiments of this invention.

0057<figref idref="DRAWINGS">FIG. 7</figref> is a flowchart illustrating the method for decoding digital moving picture signals according to the first embodiment of this invention;

0058<figref idref="DRAWINGS">FIG. 8</figref> illustrates the method for encoding digital moving picture signals according to the second embodiment of this invention; and

0059<figref idref="DRAWINGS">FIG. 9</figref> shows a structure of subframes according to the second embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

0060Hereinafter, description will be made of embodiments according to the present invention referring to the drawings.

0061A method for encoding and decoding digital moving picture signals according to a first embodiment will be now described, which may correctly decode a subframe as a unit in relation to time even if a part of a bit stream is missing or an error occurs therein.

0062In the encoding method according to this embodiment, one frame of digital motion picture signals is composed of, for example, 352×288 pixels. The frame is divided into twelve subframes each composed of, for example, 176×48 pixels. Further, the subframe is divided into thirty three blocks 13 each composed of, for example, 16×16 pixels.

0063The encoding method according to this embodiment corresponds encoded information for one frame to a spatial hierarchical structure made up of a frame 11, subframes 12 and blocks 13 to generate a bit stream 14 as shown, for example, in FIG. 6.

0064Meanings of encoded information of each layer shown in <figref idref="DRAWINGS">FIG. 6</figref> are given below: Frame layer 11S

0065FSC (20 bits): a frame identifier 15; a unique code by which a decoding method can be always identified, expressed as “0000 0000 0000 0001 0000”;

0000Subframe Layer 12S

0066SFSC (16 bits): a subframe identifier 16; a unique code by which a decoding method can be always identified, expressed as “0000 0000 0000 0001”;

0067SFNT (5 bits): a subframe time number 17; indicating a time position in which this subframe 12 should be displayed;

0068SFNS (b 4 bits): a subframe space number 18; indicating a spatial position in which the subframe 12 should be displayed;

0069SFQUANT (5 bits): quantization characteristic information 19; representing a quantization characteristic when a block 13 in the subframe 12 is encoded.

0070Incidentally, encoded information 20 in the block layer 13S which is the lowest hierarchy in <figref idref="DRAWINGS">FIG. 6</figref> is generated in an encoding method of motion detection, prediction, orthogonal transform, quantization, variable length coding, etc., whose coding bit number are not fixed.

0071Now referring to <figref idref="DRAWINGS">FIG. 7</figref>, a decoding method according to this embodiment will be now described. First, an FSC 15 which is an identifier of a frame layer 11S is found out from a bit stream 14 to establish synchronization of the frame layer 11S.

0072After the establishment of synchronization of the frame layer 11S, an SFSC 16 which is an identifier of a subframe layer 12S is found out from the following bit stream 14 to establish synchronization of the subframe layer 12S. Then a subframe time number SFNT 17 and a subframe space number SFNS 18 following the SFSC 16 are examined. Next, a bit stream 14 of a block layer 13S is decoded. A method for decoding this block layer 13S is a procedure to regenerate the block in processes of, for example, variable length decoding, reverse quantization, reverse orthogonal transform, motion compensation, etc. Finally, the subframe 12 which is a set of the regenerated blocks 13 is placed in time and space positions instructed by the SFNT 17 and the SFNS 18. If synchronization of the decoding is lost due to a lack of a part of the bit stream 14 or an error therein, a seek for the SFSC 16 which is an identifier of the subframe layer 12S is started. A lack or an error ofof a portion of, or an error in, the bit stream 14 can be detected from, for example, that a decoded value exceeds a range specified in advance or an unexpected code word appears when the bit stream 14 is decoded. When the SFSC 16 is detected and synchronization of the subframe layer 12S is established, the SFNT 17 and the SFNS 18 are examined as stated above, the block layer 13S is decoded and regenerated, and the subframe 12 which is a set of the regenerated blocks 13 is placed in time and space positions instructed by the SFNT 17 and the SFNS 18.

0073According to the first embodiment of this invention, if a part of the bit stream 14lacksis lacking or an error occurs in the bit stream 14, synchronization of the decoding is lost and the decoding becomes unfeasible, but correct decoding becomes possible immediately after a subframe 12 in trouble.

0074As having been described the above first embodiment by way of an example, it is alternatively possible that the frame 11, the subframe 12 and the block are in different sizes and shapes. A bit length of each encoded information may be different from that of the above encoded information, or the frame layer 19 may be omitted, in addition.

0075According to a second embodiment of this invention, description will be now made of a method for encoding digital moving picture signals which can suppress degradation of a reproduced picture to a small extent if a subframe including a picture moving in relation to time cannot be decoded. Incidentally, it is possible here to employ a decoding method similar to that of the first embodiment.

0076In the encoding method of this embodiment, one frame 11 of digital moving picture signals is composed of, for example, 352×288 pixels. The frame 11 is divided into blocks each composed of 16×16 pixels. In other words, one frame 11 is composed of 22 blocks×18 block lines 21. The block line 21 corresponds to the subframe 12 mentioned above.

0077In the encoding method of this embodiment, each block 13′ is encoded from the uppermost block line 21, as shown in <figref idref="DRAWINGS">FIG. 8</figref>, to generate encoded information. The encoded information of each block 13′ is generated in an encoding method of, for example, motion detection, prediction, orthogonal transform, quantization, variable length coding, etc., the number of coding bits of which is not fixed. More specifically, the number of coding bits of a block 13′ which is difficult to be encoded is large, whereas the number of coding bits of a block 13′ which is easy to be encoded is small. In the encoding method of this embodiment, a set of blocks 13 or 13′ composes a subframe 12 (or a block line 21) which is a unit of encoding, but the number of blocks 13 or 13′ included in one subframe 12 or 12′ is not fixed.

0078A manner of generating a bit stream 14 in the encoding method of this embodiment and a structure of a subframe layer 12S will be now described with reference to FIG. 6. When one frame is encoded, an identifier of a frame layer is encoded, and an FSC 15 is placed in a bit stream 14. Next, the identifier of the subframe layer 12S, a time number and a space number of that subframe, and a quantization characteristic of that subframe are encoded together, and code words of an SFSC 16, an SFNT 17, an SFNS 18 and an SFQUANT 19 are placed in the bit stream 14. At the same time, block encoding bit number integrated value B-add is set to zero. Following that, a block 13 is encoded and encoded information of the block 13 composed of variable codes is placed in the bit stream 14. Concurrently, the coding bit number B of this block 13 is added to B-add. Namely, an equation, B-add=B-add+B, is computed. Similarly, blocks 13 are encoded successively, encoded information 20 of each block 13 is placed in the bit stream 14, and a calculation of B-add=B-add+B is repeated each time. If the B-add exceeds a subframe interval SFd when encoding of a certain block 12 is completed, an identifier of the subframe, a time number and a space number of that subframe and a quantization characteristic of that subframe are encoded, and code words of an SFSC 16, and SFNT 17, an SFNS and an SFQUANT 19 are placed in the bit stream 14. At the same time, a block coding bit integrated value B-add is set to zero. In other words, a new subframe layer 12S is started to be formed from that point.

0079The subframe interval SFd is set to, for example, 540 bits. Therefore, if one frame is encoded with, for example, 6400 bits in the encoding method of this embodiment, 12 subframes 12 exist in one frame since 6400/540=11.85.

0080In the encoding method according to this embodiment, the number of blocks 13 included in a subframe 12 is varied according to a quantity of generated information of the blocks included in one subframe, thereby varying a spatial size of the subframe 12, as stated above. More specifically, a subframe 12 including a block which is difficult to be encoded becomes small, whereas a subframe 12 including a block 13 which is easy to be encoded becomes large. <figref idref="DRAWINGS">FIG. 9</figref> shows an example of a structure of subframes formed in the encoding method of this embodiment.

0081According to th ethe second embodiment of this invention, a subframe 12 including a block 13 which contains a motion in relation to time, and is thus difficult to be coded is made smaller in relation to space. If such subframe 12 cannot be decoded, it is possible to suppress degradation of a quality of a reproduced picture to a small extent. In a region within a frame in which no motion in relation to time exists and degradation of the picture quality is hardly detected even if the decoding is unfeasible, a size of one subframe is large in relation to space, which allows a less volume of side information such as the subframe identifier SFSC 16, subframe number SFNT 16 and subframe number SFNT 17. This can prevent an encoding efficiency from being lowered.

0082As having been described the second embodiment by way of an example, it is alternatively possible that the frame 11, subframe 12 and the block 13 are in different sizes and shapes. It is also possible to employ values of a quantity of codes of one frame and a subframe interval SFD different from those employed in the above example.

0083As obvious from the above embodiments, this invention enables correct decoding of each subframe 12 an a unit in relation to time even if a part of the bit stream 14 is missing or an error occurs therein.

0084Further, according to this invention, it is possible to suppress degradation of a quality of the reproduced picture to a small extent if a subframe 13 including a block which is in motion in relation to time cannot be decoded.

0085Still further, in a region within a frame in which no motion in relation to time exists and degradation of a quality of the reproduced picture quality is hardly detected even if the decoding in unfeasible, side information of the region is allowed to be in a small volume so that it is possible to prevent an encoding efficiency from being lowered.

Contents4

Every citation, both ways

Citations
Document	Relation	Office	Cited during
EP0055049A1	Cites	European Patent Office (EPO)	Search report
GB2287603A	Cites	United Kingdom	Search report
US5023710A	Cites	United States of America	Search report
US5060285A	Cites	United States of America	Search report
US5107345A	Cites	United States of America	Search report
US5138447A	Cites	United States of America	Search report
US5144424A	Cites	United States of America	Search report
US5173952A	Cites	United States of America	Search report
US5203715A	Cites	United States of America	Search report
US5231384A	Cites	United States of America	Search report
US5287178A	Cites	United States of America	Search report
US5397095A	Cites	United States of America	Search report
US5557331A	Cites	United States of America	Applicant
JPH02272851A	Cites	Japan	Applicant
JPH07111651A	Cites	Japan	Applicant
JPH0715729A	Cites	Japan	Applicant
EP55049	Cites	European Patent Office (EPO)	Search report
GB2287603	Cites	United Kingdom	Search report
JP2272851	Cites	Japan	Third party observation
JP715729	Cites	Japan	Third party observation
JP7111651	Cites	Japan	Third party observation
"Codec for AFdiovisual Services AT nx384kbits/s" Cornite Consultatif International Telegraphique Telefonique Recommendation, vol. 3, No. iii.06, Nov. 14, 1998, pp. 120-128, XP000575342.	Non-patent	–	Search report
"Transmission of Non-Telephone Signals. Information Technology-Generic Coding of Moving Pictures and Associated Audio Information: Video" ITU-T Telecommunication Standarization Sector of ITU, Jul. 1995, pp. A/B, I-VIII, 1-201, XP000198491.	Non-patent	–	Search report
Line Transmission of Non-Telephone Signals, International Telecommunication Union, ITU-T Tecommendation H.261, Mar. 1993, pp. 1-25.	Non-patent	–	Search report
“Codec for AFdiovisual Services AT n×384kbits/s” Cornite Consultatif International Telegraphique Telefonique Recommendation, vol. 3, No. iii.06, Nov. 14, 1998, pp. 120-128, XP000575342.	Non-patent	–	Search report
“Transmission of Non-Telephone Signals. Information Technology-Generic Coding of Moving Pictures and Associated Audio Information: Video” ITU-T Telecommunication Standarization Sector of ITU, Jul. 1995, pp. A/B, I-VIII, 1-201, XP000198491.	Non-patent	–	Search report
Line Transmission of Non-Telephone Signals, International Telecommunication Union, ITU-T Tecommendation H.261, Mar. 1993, pp. 1-25.	Non-patent	–	Search report

27 members in 6 offices

This recordMember, by publication datePriority claim

Priority claims15

Priority claims
Document	Office	Kind	Date
1451495	Japan	A	1995-01-31
1451495	Japan	A	1995-01-31
7014514	Japan	–	1995-01-31
59456596	United States of America	A	1996-01-31
59456596	United States of America	A	1996-01-31
92542301	United States of America	A	2001-08-10
92542301	United States of America	A	2001-08-10
66294903	United States of America	A	2003-09-16
08594565	–	–	–
09925423	–	–	–
7014514	–	–	–
JP19950014514	–	–	–
US19960594565	–	–	–
US20010925423	–	–	–
US20030662949	–	–	–

Members27

Family members, oldest first
Document	Office	Kind
CA2168415A1	Canada	A1	1996-08-01
EP0725545A2	European Patent Office (EPO)	A2	1996-08-07
AU4331096A	Australia	A	1996-08-08
JPH08205155A	Japan	A	1996-08-09
AU2359097A	Australia	A	1997-08-14
AU681818B2	Australia	B2	1997-09-04
AU684697B2	Australia	B2	1997-12-18
EP0725545A3	European Patent Office (EPO)	A3	1999-01-27
US5937095A	United States of America	A	1999-08-10
CA2168415C	Canada	C	2000-07-18
EP1146747A2	European Patent Office (EPO)	A2	2001-10-17
EP1146747A3	European Patent Office (EPO)	A3	2002-03-13
EP1189453A1	European Patent Office (EPO)	A1	2002-03-20
EP0725545B1	European Patent Office (EPO)	B1	2002-05-02
DE69620932D1	Germany	D1	2002-06-06
DE69620932T2	Germany	T2	2002-11-07
JP3351645B2	Japan	B2	2002-12-03
USRE38726E	United States of America	E	2005-04-19
EP1146747B1	European Patent Office (EPO)	B1	2006-09-06
DE69636529D1	Germany	D1	2006-10-19
USRE39367EThis record	United States of America	E	2006-10-31
DE69636529T2	Germany	T2	2007-01-18
EP1991007A2	European Patent Office (EPO)	A2	2008-11-12
USRE40828E	United States of America	E	2009-07-07
USRE40829E	United States of America	E	2009-07-07
USRE41180E	United States of America	E	2010-03-30
EP1991007A3	European Patent Office (EPO)	A3	2011-09-14

49 transactions on the USPTO file

Allowed after 1 non-final rejection.

Non-final rejections: 1
Final rejections: 0
RCEs: 0
Appeals: 0

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	Event	Code
2006-10-31	Recordation of Patent Grant MailedPGM/	PGM/
2006-10-11	Issue Notification MailedAllowedWPIR	WPIR
2006-10-04	Receipt into PubsR1021	R1021
2006-09-28	Dispatch to FDCD1935	D1935
2006-09-20	Dispatch to FDCD1935	D1935
2006-08-29	Cleared by OIPE CSRL194	L194
2006-08-23	Dispatch to FDCD1935	D1935
2006-08-23	Application Is Considered Ready for IssuePILS	PILS
2006-08-15	Cleared by OIPE CSRL194	L194
2006-08-10	Mail Response to 312 Amendment (PTO-271)MN271	MN271
2006-08-07	Response to Amendment under Rule 312N271	N271
2006-07-24	Cleared by OIPE CSRL194	L194
2006-05-20	Cleared by OIPE CSRL194	L194
2006-05-10	Cleared by OIPE CSRL194	L194
2006-04-28	Amendment after Notice of Allowance (Rule 312)AllowedA.NA	A.NA
2006-03-23	Cleared by OIPE CSRL194	L194
2006-03-14	Supplemental Papers - Oath or DeclarationC600	C600
2006-02-13	Mail Examiner Interview Summary (PTOL - 413)MEXIN	MEXIN
2006-02-06	Examiner Interview Summary Record (PTOL - 413)EXIN	EXIN
2006-01-10	Supplemental Papers - Oath or DeclarationC600	C600
2005-11-04	Cleared by OIPE CSRL194	L194
2005-10-14	Issue Fee Payment VerifiedN084	N084
2005-10-14	Issue Fee Payment ReceivedIFEE	IFEE
2005-07-28	Workflow - File Sent to ContractorSENT	SENT
2005-07-19	Mail Notice of AllowanceAllowedMN/=.	MN/=.
2005-07-19	Mail Examiner's AmendmentMEX.A	MEX.A
2005-06-27	Notice of Allowance Data Verification CompletedAllowedN/=.	N/=.
2005-06-01	Correspondence Address ChangeC.ADB	C.ADB
2005-01-14	Case Docketed to Examiner in GAUDOCK	DOCK
2005-01-14	Examiner's Amendment CommunicationEX.A	EX.A
2004-12-20	IFW TSS Processing by Tech Center CompleteTSSCOMP	TSSCOMP
2004-12-19	Date Forwarded to ExaminerFWDX	FWDX
2004-11-16	Response after Non-Final ActionA...	A...
2004-09-16	Request for Foreign Priority (Priority Papers May Be Included)RQPR	RQPR
2004-08-16	Mail Non-Final RejectionNon-final rejectionMCTNF	MCTNF
2004-08-12	Non-Final RejectionNon-final rejectionCTNF	CTNF
2004-06-28	Case Docketed to Examiner in GAUDOCK	DOCK
2004-06-01	Application Is Now CompleteCOMP	COMP
2004-05-28	Application Dispatched from OIPEOIPE	OIPE
2004-03-29	Reference capture on IDSRCAP	RCAP
2004-03-29	Information Disclosure Statement (IDS) FiledM844	M844
2004-03-29	Information Disclosure Statement (IDS) FiledWIDS	WIDS
2004-03-29	Additional Application Filing FeesADDFLFEE	ADDFLFEE
2004-03-29	The identification of one or more legal entities other than the inventor(s), each such legal entityASGMT	ASGMT
2004-03-02	Notice of Reissue Published in Official GazetteNRE.	NRE.
2004-01-28	Notice Mailed--Application Incomplete--Filing Date AssignedINCD	INCD
2003-11-28	Cleared by OIPE CSRL194	L194
2003-10-27	IFW Scan & PACR Auto Security ReviewSCAN	SCAN
2003-09-16	Initial Exam Team nnIEXX	IEXX

1 legal event, as the office reported them to INPADOC

Events

Legal events, newest first
	Event	Code
2006-12-09	Fee payment procedurePAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITYFEPP	FEPP