US20140169476A1 - Method and Device for Encoding a Sequence of Images and Method and Device for Decoding a Sequence of Image - Google Patents

Method and Device for Encoding a Sequence of Images and Method and Device for Decoding a Sequence of Image Download PDF

Info

Publication number
US20140169476A1
US20140169476A1 US14/123,941 US201214123941A US2014169476A1 US 20140169476 A1 US20140169476 A1 US 20140169476A1 US 201214123941 A US201214123941 A US 201214123941A US 2014169476 A1 US2014169476 A1 US 2014169476A1
Authority
US
United States
Prior art keywords
motion information
predictor
predictors
motion
information predictors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/123,941
Other languages
English (en)
Inventor
Guillaume Laroche
Patrice Onno
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Assigned to CANON KABUSHIKI KAISHA reassignment CANON KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LAROCHE, GUILLAUME, ONNO, PATRICE
Publication of US20140169476A1 publication Critical patent/US20140169476A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/105—Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
    • H04N19/00575—
    • H04N19/00684—
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
    • H04N19/174—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a slice, e.g. a line of blocks or a group of blocks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
    • H04N19/176—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a block, e.g. a macroblock
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/44—Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H04N19/51—Motion estimation or motion compensation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H04N19/51—Motion estimation or motion compensation
    • H04N19/513—Processing of motion vectors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H04N19/51—Motion estimation or motion compensation
    • H04N19/513—Processing of motion vectors
    • H04N19/517—Processing of motion vectors by encoding
    • H04N19/52—Processing of motion vectors by encoding by predictive encoding
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/65—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using error resilience
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/70—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals characterised by syntax aspects related to video coding, e.g. related to compression standards
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/85—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using pre-processing or post-processing specially adapted for video compression
    • H04N19/89—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using pre-processing or post-processing specially adapted for video compression involving methods or arrangements for detection of transmission errors at the decoder

Definitions

  • the present invention concerns a method and device for encoding a sequence of digital images and a method and device for decoding a corresponding bitstream.
  • the invention further relates to a method and device for deriving motion information of an image portion of an image predicted by motion prediction with respect to at least one reference image
  • the invention belongs to the field of digital signal processing, and in particular to the field of video compression using motion compensation to reduce spatial and temporal redundancies in video streams.
  • Video compression formats such as for example H.263, H.264, MPEG-1, MPEG-2, MPEG-4, SVC, use block-based discrete cosine transform (DCT) and motion compensation to remove spatial and temporal redundancies. They can be referred to as predictive video formats.
  • DCT discrete cosine transform
  • Each frame or image of the video signal is divided into slices which are encoded and can be decoded independently.
  • a slice is typically a rectangular portion of the frame, or more generally, a portion of a frame or an entire frame.
  • each slice is divided into macroblocks (MBs), and each macroblock is further divided into blocks, typically blocks of 8 ⁇ 8 pixels.
  • the encoded frames are of two types: temporal predicted frames (either predicted from one reference frame called P-frames or predicted from two reference frames called B-frames) and non temporal predicted frames (called Intra frames or I-frames).
  • Temporal prediction consists in finding in a reference frame, either a previous or a future frame of the video sequence, an image portion or reference area which is the closest to the block to encode. This step is known as motion estimation.
  • the block is predicted using the reference area (motion compensation)—the difference between the block to encode and the reference portion is encoded, along with an item of motion information relative to the motion vector which indicates the reference area to use for motion compensation.
  • motion vectors are encoded with respect to a median predictor computed from the motion vectors situated in a causal neighbourhood of the block to encode, for example from the blocks situated above and to the left of the block to encode. Only the difference, also called residual motion vector, between the median predictor and the current block motion vector is encoded.
  • Encoding using residual motion vectors saves some bitrate, but necessitates that the decoder performs the same computation of the motion vector predictor in order to decode the value of the motion vector of a block to decode.
  • the residual motion information comprises the residual motion vector, i.e. the difference between the actual motion vector of the block to encode and the selected motion vector predictor, and an item of information indicating the selected motion vector predictor, such as for example an encoded value of the index of the selected motion vector predictor.
  • HEVC High Efficiency Video Coding
  • the 3 spatial motion vector predictors are taken from the block situated to the left of the block to encode (V 3 ), the block situated above (V 2 ) and from one of the blocks situated at the respective corners of the block to encode, according to a predetermined rule of availability.
  • This motion vector predictor selection scheme is called Advanced Motion Vector Prediction (AMVP) which allows the selection of the best predictor from a given set.
  • AMVP Advanced Motion Vector Prediction
  • the set of motion vector predictors is reduced by eliminating the duplicate motion vectors, i.e. the motion vectors which have the same value.
  • V 1 and V 2 are equal, and V o and V 3 are also equal, so only two of them should be kept as motion vector prediction candidates, for example V o and V 1 . In this case, only one bit is necessary to indicate the index of the motion vector predictor to the decoder.
  • a further reduction of the set of motion vector predictors, based on the values of the predictors, is possible. Once the best motion vector predictor is selected and the motion vector residual is computed, it is possible to further eliminate from the prediction set the candidates which would have not been selected, knowing the motion vector residual and the cost optimization criterion of the encoder.
  • a sufficient reduction of the set of predictors leads to a gain in the signaling overhead, since the indication of the selected motion vector predictor can be encoded using fewer bits.
  • the set of candidates may even be reduced to 1, for example if all motion vector predictors are equal. In such a case it is not necessary to insert any information relative to the selected motion vector predictor in the bitstream since the decoder can infer the motion vector predictor value.
  • AMVP the optimal amount of spatial and temporal predictors can be evaluated.
  • a current implementation includes 2 spatial predictors and one temporal collocated predictor, for example.
  • One known problem of video streams is their relative fragility to transmission errors.
  • the main issue is related to error propagation. Indeed, due to prediction, one error in a bitstream portion may propagate to other received portions.
  • the bitstream was constructed so that even with errors, the bitstream can still be read by the decoder allowing it to resynchronize the decoding after a reasonable time.
  • AMVP One issue associated with AMVP, is the heavy risk of bitstream de-synchronization in case of losses.
  • the problem occurs when one motion vector predictor is lost. In that case, the decoder cannot apply the suppression algorithm in the same context as the encoder. Indeed, if one motion vector is missing, it is impossible to determine if this missing motion vector predictor was equal to at least one of the other motion vector predictors or not.
  • the decoder since the number of bits allocated to the index of motion vector predictor signaling depends on the amount of motion vector predictors remaining after the suppression algorithm, the decoder is no longer capable of determining how many bits have to be read for the index. This causes a de-synchronization of the decoder that may prevent the complete bitstream from being decoded until the next re-synchronization frame (IDR frame in H.264/AVC). Up to this frame, visually, the sequence is frozen.
  • One approach sets out to address this problem by a determination of the number of predictors according to the data which comes from the current slice. Consequently, the number of predictors does not depend on the value of the motion vector. This provides to the parsing a robustness to transmission errors.
  • a duplicate candidate in a predictor set which is a duplicate of any another candidate in the predictor set is removed and replaced by non-duplicate candidate. This offers an optimal use of the number of bits dedicated to the predictor index.
  • Another advantage is that the parsing complexity is reduced compared to HEVC because the motion vector field does not need to be built for parsing application.
  • FIG. 2 illustrates the flow chart of a predictor index coding method using such an approach.
  • step 601 the number of predictors in a predictor set is determined and according to the data from the current slice rather than from the motion vector value which could depend on other slices.
  • step 602 the number of predictors is provided.
  • step 604 the predictor index 603 of the best predictor selected based on rate distortion (RD) criterion is converted to a code word 605 and this code word 605 is then entropy coded in step 606 .
  • RD rate distortion
  • FIG. 3 shows the flow chart of the AMVP scheme applying the above approach at the decoder side.
  • step 703 the number of predictors 704 is determined and provided. The number of predictors 704 is then used in step 705 for the entropy decoding of the predictor index code word 706 retrieved from the bitstream 702 .
  • step 707 the code word obtained in step 706 is converted to an index defining the motion vector predictor index 708 . This process is sufficient for index decoding or the predictor index parsing.
  • a first list of predictors 710 is derived in step 709 according to the motion vectors field and the reference frame index obtained in step 701 .
  • a suppression process is then applied 711 to produce a reduced motion vector predictors set 712 .
  • step 713 a set of non duplicate predictors is generated, each candidate predictor is compared to all predictors in the list to determine if it is a duplicate of another predictor according to the number of predictors in the final predictor set provided in step 714 .
  • Motion vector derivation has a significant impact on encoding and decoding complexity. Indeed, for the current HEVC motion vector derivation, each predictor position (above, left, temporal, below left, above right) should be derived. Such derivation processes involve memory accesses, scalings, etc. . . . Moreover, each predictor is compared to all other predictors in order to eliminate duplicate candidates Indeed such a derivation process may take up to 6 to 10% of the decoding process.
  • the present invention has been devised to address one or more of the foregoing concerns.
  • a method of decoding a bitstream comprising an encoded sequence of images, at least one portion of an image having been encoded by motion compensation with respect to a reference image portion, the method comprising for at least one image portion to be decoded: obtaining an index i of a selected motion information predictor of a first set of motion information predictors for decoding the image portion; generating a second set of motion information predictors consisting of said index number i of motion information predictors, wherein there are no duplicates among the i motion information predictors of said second set, and retrieving, for decoding of the image portion, the motion information predictor indexed by index i from the second set of motion information predictors.
  • the number of motion information predictors derived is limited to the index number i the number of processing operation is reduced. Moreover since each motion information predictor is only compared with previously derived motion information predictor of the new set the number of processing operations is further reduced and decoding efficiency is improved.
  • the step of generating a second set of motion information predictors comprises: obtaining a motion information predictor j for the second set of motion information predictors, comparing the obtained motion information predictor to any previously obtained motion information predictor, 0 to j ⁇ 1, of the second set of motion information predictors; wherein in the case where the obtained motion information predictor j is different to any of the previously obtained motion information predictors 0 to j ⁇ 1 the obtained motion information predictor is added to the second set of motion information predictors, otherwise the obtained motion information predictor is replaced with a motion information predictor different to any of the previously derived predictors j ⁇ 1.
  • the replacement motion information predictor may be derived according to the value of the obtained motion information predictor j and data of a motion vector field storing encoded motion vectors of the current image and of previous images of the sequence.
  • the method may include a step of comparing the replacement motion information predictor with each of the previously obtained motion information predictors 0 to j ⁇ 1, of the second set of motion information predictors and in the case where the replacement motion information predictor is not different to each of the previously obtained motion information predictors 0 to j ⁇ 1, the method further comprising deriving another replacement motion information predictor.
  • the method may include a step of determining the number of motion information predictors in the first set of motion information predictors and retrieving an information item to provide the index i of the selected motion information predictor based on the number of motion information predictors.
  • a method of encoding a sequence of images into a bitstream, at least one portion of an image being encoded by motion compensation with respect to a reference image portion comprising for at least one image portion to encode obtaining a number x of motion information predictors taken from a first set of N motion information predictors, wherein the number x is based on a threshold parameter; and generating a second set of motion information predictors consisting of said number x of motion information predictors, wherein there are no duplicates among the x motion information predictors of said second set, and selecting, from among the second set of motion information predictors a motion information predictor for encoding the image portion; and encoding an information i to provide an index i of the selected motion information predictor.
  • the step of generating a second set of motion information predictors comprises: obtaining a motion information predictor j for the second set of motion information predictors, comparing the obtained motion information predictor to any previously obtained motion information predictor 0 to j ⁇ 1 of the second set of motion information predictors; wherein in the case where the obtained motion information predictor j is different to any of the previously obtained motion information predictors 0 to j ⁇ 1 the obtained motion information predictor is added to the second set of motion information predictors, otherwise the obtained information predictor is replaced with a motion information predictor different to any of the previously derived predictors j ⁇ 1.
  • the threshold parameter may based on a maximum allowed number of motion information predictors, a rate distortion criterion and/or a threshold number of operations for obtaining the second set of motion information predictors.
  • each of the following steps may be considering as at least one elementary operation: the step of obtaining a motion information predictor j, the step of comparing the obtained motion information predictor to a previously obtained motion information predictor 0 to j ⁇ 1 of the second set of motion information predictors, the step of replacing a motion information predictor j with a replacement motion information predictor, and the step of obtaining a replacement motion information predictor.
  • the item of information may be encoded on a number of bits dependent upon the number N of motion information predictors.
  • the motion information predictor may be selected based on a rate distortion criterion
  • a further aspect of the invention provides a method of deriving motion information of an image portion of an image predicted by motion prediction with respect to at least one reference image, the method comprising for said image portion: obtaining a number i of motion information predictors of a second set of motion information predictors taken in a first set of motion information predictors for decoding the image portion; generating said second set of motion information predictors consisting of said number i of motion information predictors, wherein there are no duplicates among the i motion information predictors of said second set.
  • an embodiment of the invention may provide a method of decoding a bitstream comprising an encoded sequence of images, at least one portion of an image having been encoded by motion compensation with respect to a reference image portion, the method comprising for at least one image portion to be decoded: a step of deriving motion information of the image portion according to the further aspect, wherein the number i is an index of a selected motion information predictor in said first set of motion information predictors obtained during a encoding process applied to said image; and
  • Another embodiment of the invention may provide a method of encoding a sequence of images into a bitstream, at least one portion of an image being encoded by motion compensation with respect to a reference image portion, the method comprising for at least one image portion to decode a step of deriving motion information of the image portion according to the further aspect; and selecting, from among the set of motion information predictors a motion information predictor for encoding the image portion; and encoding an information item to provide an index i 2 of the selected motion information predictor.
  • a third aspect of the invention may provide a decoding device for decoding a bitstream comprising an encoded sequence of images, at least one portion of an image having been encoded by motion compensation with respect to a reference image portion, the decoding device comprising: index obtaining means for obtaining an index i of a selected motion information predictor of a first set of motion information predictors for decoding the image portion; motion information set generation means for generating a second set of motion information predictors consisting of said index number i of motion information predictors, wherein there are no duplicates among the i motion information predictors of said second set, and retrieval means for retrieving, for decoding of the image portion, the motion information predictor indexed by index i from the second set of motion information predictors.
  • the motion information set generation means may include: means for obtaining a motion information predictor j for the second set of motion information predictors, comparison means for comparing the obtained motion information predictor to any previously obtained motion information predictor, 0 to j ⁇ 1, of the second set of motion information predictors; wherein in the case where the obtained motion information predictor j is different to any of the previously obtained motion information predictors 0 to j ⁇ 1 the motion information set generation means is operable to add the obtained motion information predictor to the second set of motion information predictors, otherwise the obtained motion information predictor is replaced with a replacement motion information predictor different to any of the previously derived predictors 0 to j ⁇ 1.
  • the motion information set generation means may be operable to derive the replacement motion information predictor according to the value of the obtained motion information predictor j and data of a motion vector field storing encoded motion vectors of the current image and of previous images of the sequence.
  • the comparison means is operable to compare the replacement motion information predictor with each of the previously obtained motion information predictors 0 to j ⁇ 1, of the second set of motion information predictors and in the case where the replacement motion information predictor is not different to each of the previously obtained motion information predictors 0 to j ⁇ 1, the motion information set generation means is operable to derive another replacement motion information predictor.
  • the device includes means for determining the number of motion information predictors in the first set of motion information predictors and means for retrieving an information item to provide the index i of the selected motion information predictor based on the number of motion information predictors.
  • an encoding device for encoding a sequence of images into a bitstream, at least one portion of an image being encoded by motion compensation with respect to a reference image portion, the encoding device comprising: means for obtaining a number x, of motion information predictors taken from a first set of N motion information predictors wherein the number x is based on a threshold parameter; and motion information set generation means for generating a set of motion information predictors consisting of said number x of motion information predictors, wherein there are no duplicates among the x motion information predictors of said second set, and selection means for selecting, from among the second set of motion information predictors a motion information predictor for encoding the image portion; and encoding means for encoding an information item to provide an index i of the selected motion information predictor.
  • the motion information set generation means comprises: means for obtaining a motion information predictor j for the second set of motion information predictors, comparison means for comparing the obtained motion information predictor to any previously obtained motion information predictor 0 to j ⁇ 1 of the second set of motion information predictors; wherein in the case where the obtained motion information predictor j is different to any of the previously obtained motion information predictors 0 to j ⁇ 1 the motion information set generation means is operable to add the obtained motion information predictor to the second set of motion information predictors, otherwise to replace the obtained information predictor with a motion information predictor different to any of the previously derived predictors 0 to j ⁇ 1.
  • the threshold parameter may be based on a maximum allowed number of motion information predictors, a rate distortion criterion, and/or a threshold number of operations for obtaining the second set of motion information predictors.
  • each of the following steps is considered respectively as at least one elementary operation: the step of obtaining a motion information predictor j, the step of comparing the obtained motion information predictor to a previously obtained motion information predictor 0 to j ⁇ 1 of the set of motion information predictors, the step of replacing a motion information predictor j with a replacement motion information predictor, and the step of obtaining a replacement motion information predictor.
  • the encoding means is operable to encode said item of information on a number of bits dependent upon the number N of motion information predictors.
  • the selection means is operable to select the motion information predictor based on a rate distortion criterion.
  • the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit”, “module” or “system”.
  • the present invention may take the form of a computer program product embodied in any tangible medium of expression having computer usable program code embodied in the medium.
  • a tangible carrier medium may comprise a storage medium such as a floppy disk, a CD-ROM, a hard disk drive, a magnetic tape device or a solid state memory device and the like.
  • a transient carrier medium may include a signal such as an electrical signal, an electronic signal, an optical signal, an acoustic signal, a magnetic signal or an electromagnetic signal, e.g. a microwave or RF signal.
  • FIG. 1 is a schematic diagram of a set of motion vector predictors used in a motion vector prediction process
  • FIG. 2 is a flow chart illustrating steps of an encoding process of the prior art
  • FIG. 3 is a flow chart illustrating steps of an decoding process of the prior art
  • FIG. 4 is a block diagram illustrating components of a processing device in which embodiments of the invention may be implemented
  • FIG. 5 is a block diagram illustrating components of an encoder device according to embodiments of the invention.
  • FIG. 6 is a block diagram illustrating components of a decoder device according to embodiments of the invention.
  • FIG. 7 is a flow chart illustrating steps of a decoding process according to an embodiment of the invention.
  • FIG. 8 is a flow chart illustrating steps of a general encoding process according to embodiments of the invention.
  • FIG. 9 is a flow chart illustrating steps of an encoding process in which embodiments of the invention may be implemented.
  • FIG. 10 is a flow chart illustrating an encoding process according to an embodiment of the invention.
  • FIG. 11 is a flow chart illustrating an encoding process according to a further embodiment of the invention.
  • FIG. 12 is a schematic diagram of a set of motion vector predictors used in a motion vector prediction process.
  • FIG. 4 schematically illustrates a processing device 200 configured to implement at least one embodiment of the present invention.
  • the processing device 200 may be a device such as a micro-computer, a workstation or a light portable device.
  • the device 200 comprises a communication bus 213 to which there are preferably connected:
  • the apparatus 200 may also include the following components:
  • the apparatus 200 can be connected to various peripherals, such as for example a digital camera 200 or a microphone 208 , each being connected to an input/output card (not shown) so as to supply multimedia data to the apparatus 200 .
  • peripherals such as for example a digital camera 200 or a microphone 208 , each being connected to an input/output card (not shown) so as to supply multimedia data to the apparatus 200 .
  • the communication bus provides communication and interoperability between the various elements included in the apparatus 200 or connected to it.
  • the representation of the bus is not limiting and in particular the central processing unit is operable to communicate instructions to any element of the apparatus 200 directly or by means of another element of the apparatus 200 .
  • the disk 206 can be replaced by any information medium such as for example a compact disk (CD-ROM), rewritable or not, a ZIP disk or a memory card and, in general terms, by an information storage means that can be read by a microcomputer or by a microprocessor, integrated or not into the apparatus, possibly removable and adapted to store one or more programs whose execution enables the method of encoding a sequence of digital images and/or the method of decoding a bitstream according to the invention to be implemented.
  • CD-ROM compact disk
  • ZIP disk or a memory card
  • an information storage means that can be read by a microcomputer or by a microprocessor, integrated or not into the apparatus, possibly removable and adapted to store one or more programs whose execution enables the method of encoding a sequence of digital images and/or the method of decoding a bitstream according to the invention to be implemented.
  • the executable code may be stored either in read only memory 207 , on the hard disk 204 or on a removable digital medium such as for example a disk 206 as described previously.
  • the executable code of the programs can be received by means of the communication network 203 , via the interface 202 , in order to be stored in one of the storage means of the apparatus 200 before being executed, such as the hard disk 204 .
  • the central processing unit 211 is adapted to control and direct the execution of the instructions or portions of software code of the program or programs according to the invention, instructions that are stored in one of the aforementioned storage means.
  • the program or programs that are stored in a non-volatile memory for example on the hard disk 204 or in the read only memory 207 , are transferred into the random access memory 212 , which then contains the executable code of the program or programs, as well as registers for storing the variables and parameters necessary for implementing the invention.
  • the apparatus is a programmable apparatus which uses software to implement the invention.
  • the present invention may be implemented in hardware (for example, in the form of an Application Specific Integrated Circuit or ASIC).
  • FIG. 5 illustrates a block diagram of an encoder according to at least one embodiment of the invention.
  • the encoder is represented by connected modules, each module being adapted to implement, for example in the form of programming instructions to be executed by the CPU 211 of device 200 , at least one corresponding step of a method implementing at least one embodiment of the invention.
  • An original sequence of digital images 10 to in 301 is received as an input by the encoder 30 .
  • Each digital image is represented by a set of samples, known as pixels.
  • a bitstream 310 is output by the encoder 30 after implementation of the encoding process.
  • the bitstream 310 comprises a plurality of encoding units or slices, each slice comprising a slice header for transmitting encoding values of encoding parameters used to encode the slice and a slice body, comprising encoded video data.
  • the input digital images i 0 to in 301 are divided into blocks of pixels by module 302 .
  • the blocks are image portions and may be of variable sizes (e.g. 4 ⁇ 4, 8 ⁇ 8, 16 ⁇ 16, 32 ⁇ 32).
  • a coding mode is selected for each input block.
  • Module 303 implements Intra prediction, in which the given block to be encoded is predicted by a predictor computed from pixels of the neighbourhood of said block to be encoded. An indication of the Intra predictor selected and the difference between the given block and its predictor is encoded to provide a residual if the Intra coding is selected.
  • Temporal prediction is implemented by motion estimation module 304 and motion compensation module 305 .
  • a reference image from among a set of reference images 316 is selected, and a portion of the reference image, also called reference area, which is the closest area to the given block to be encoded, is selected by the motion estimation module 304 .
  • Motion compensation module 305 then predicts the block to be encoded using the selected area.
  • the difference between the selected reference area and the given block, also called a residual block, is computed by the motion compensation module 305 .
  • the selected reference area is indicated by a motion vector.
  • a residual is computed by subtracting the prediction from the original predicted block.
  • a prediction direction is encoded.
  • at least one motion vector is encoded.
  • An information relative to the motion vector and the residual block is encoded if the Inter prediction is selected.
  • the motion vector is encoded by difference with respect to a motion vector predictor.
  • a set of motion vector predictors also called motion information predictors, is obtained from the motion vectors field 318 by a motion vector prediction and coding module 317 .
  • the set of motion vector predictors used to select a best motion vector predictor to encode a current motion vector is generated as explained in more detail hereafter with respect to FIGS. 10 and 11 .
  • a number N of motion vector predictors is determined, and consequently the index of the selected motion vector predictor, which is an item of information representative of the selected motion vector predictor, can be encoded using a predetermined number of bits according to the number N of motion vector predictors. This predetermined number of bits can be also retrieved by the decoder even in case of losses, therefore it may be ensured that the decoder will be able to parse the bitstream even in case of errors or losses.
  • the N motion vector predictors are selected according to various embodiments of the invention to be all different from one another so as to enhance the compression efficiency.
  • Determining the number N of motion vector predictors and of the corresponding number of bits to encode the index of the motion vector predictor can be applied either for the entire sequence, or for a group of images of the sequence, or at the block level depending on an encoding parameters such as the block size or the encoding mode.
  • a first number of motion vector predictors N 1 can be used for the blocks encoded using Inter prediction for which a residual block is encoded
  • a second number of motion vector predictors N 2 can be used for the blocks encoded using the SKIP mode, for which only a motion vector is encoded, but no residual block.
  • the respective numbers of motion vector predictors N 1 and N 2 can be for example signaled in the bitstream by inserting them in a header, such as the slice header, or in any appropriate metadata field.
  • the encoder 30 further comprises a module 306 for selection of the coding mode 306 , which uses an encoding cost criterion, such as a rate-distortion criterion, to determine which is the best mode between the spatial prediction mode and the temporal prediction mode.
  • an encoding cost criterion such as a rate-distortion criterion
  • a transform 307 is applied to the residual block, the transformed data obtained is then quantized by module 308 and entropy encoded by module 309 .
  • the encoded residual block of the current block to encode is inserted into the bitstream 310 , along with the information relative to the predictor used—the index of the selected motion vector predictor. For the blocks encoded in ‘SKIP’ mode, only a reference to the predictor is encoded in the bitstream, without any residual block.
  • the encoder 30 further performs decoding of the encoded image in order to produce a reference image for the motion estimation of the subsequent images. This enables the encoder and the decoder receiving the bitstream to have the same reference frames.
  • the module 311 performs inverse quantization of the quantized data, followed by an inverse transform 312 .
  • the reverse intra prediction module 313 uses the prediction information to determine which predictor to use for a given block and the reverse motion compensation module 314 actually adds the residual obtained by module 312 to the reference area obtained from the set of reference images 316 .
  • a deblocking filter 315 is applied to remove the blocking effects and enhance the visual quality of the decoded image. The same deblocking filter is applied at the decoder, so that, if there is no transmission loss, the encoder and the decoder apply the same processing.
  • FIG. 6 illustrates a block diagram of a decoder 40 according to at least one embodiment of the invention.
  • the decoder is represented by connected modules, each module being adapted to implement, for example in the form of programming instructions to be executed by the CPU 211 of device 200 , a corresponding step of a method implementing an embodiment of the invention.
  • the decoder 40 receives a bitstream 401 comprising encoding units, each one being composed of a header containing information on encoding parameters and a body containing the encoded video data.
  • the encoded video data is entropy encoded, and the motion vector predictors' indexes are encoded, for a given block, on a predetermined number of bits.
  • the received encoded video data is entropy decoded by module 402 .
  • the residual data are then dequantized by module 403 and then a reverse transform is applied by module 404 to obtain pixel values.
  • the mode data are also entropy decoded and based on the mode, an INTRA type decoding or an INTER type decoding is performed.
  • an INTRA predictor is determined by intra reverse prediction module 405 based on the intra prediction mode specified in the bitstream.
  • the motion prediction information is extracted from the bitstream so as to find the reference area used by the encoder.
  • the motion prediction information is composed of the reference frame index and the motion vector residual.
  • the motion vector predictor is added to the motion vector residual in order to obtain the motion vector by motion vector decoding module 410 .
  • Motion vector decoding module 410 applies motion vector decoding for each current block encoded by motion prediction.
  • the method applied comprises determining the number N max of motion vector predictors used and retrieving the motion vector predictor index encoded on a number of bits dependent on N max .
  • the motion vector decoding module 410 generates a set of motion vector predictors according to embodiments of the invention explained hereafter with reference to FIG. 7 .
  • the actual value of the motion vector associated with the current block can be decoded and used to apply reverse motion compensation by module 406 .
  • the reference area indicated by the decoded motion vector is extracted from a reference image 408 to apply the reverse motion compensation 406 .
  • the motion vector field data 411 is updated with the decoded motion vector in order to be used for the inverse prediction of the next decoded motion vectors.
  • a decoded block is obtained.
  • a deblocking filter 407 is applied, similarly to the deblocking filter 315 applied at the encoder.
  • a decoded video signal 409 is finally provided by the decoder 40 .
  • FIG. 7 is a flow chart illustrating steps of a decoding process according to an embodiment of the invention.
  • step 803 the number N of motion information predictors 804 in a set of motion information predictors is determined. The number of predictors in the set is determined based on data from the current slice. Based on this this number N, in step 805 the entropy decoding module extracts the code word 806 from the bitstream 802 . This code word 806 is then converted in step 807 to the selected motion vector predictor index 808 .
  • the selected motion vector predictor index is denoted i in the description which follows. This index i of predictor may be equal for example to 0, 1, 2, 3 and 4. Indeed, for example, the maximum number of predictors in the current implementation of HEVC is 5.
  • the method includes:
  • Module 809 initializes the value of the motion information predictor counter variable “j”, indexing the predictors in the set, to 0.
  • the selected predictor index i which has been retrieved in steps 805 to 807 described above is transmitted to a decision module 810 .
  • the decision module 810 checks if predictor counter variable “j” is equal to “i+1”. When j is equal to 0, the module 810 returns the answer “no”. Next, the module 811 derives the candidate number “j”.
  • a non-duplicate predictor is generated for the predictor j in step 815 .
  • the module 815 performing the step may be combination of module 811 where a predictor j is generated and module 812 where the generated predictor j is compared with other previously derived predictors in the constructed list where at the end of the process the generated predictor is a non-duplicate predictor—i.e.
  • the module 815 derives a predictor value according to the data of the motion vector field and the value of the current duplicate predictor (if needed), and that this module checks if this value is a duplicate candidate or not. To check if this generated predictor is a duplicate value, the predictor is compared to all predictors which have already been derived and added to the constructed list 814 . If the generated value is again a duplicate predictor, another predictor value is derived until a non-duplicate predictor is found. At the end of the process in step 815 , the non-duplicate predictor is added in step 813 to the constructed list 814 and the counter variable “j” is incremented in the module 816 .
  • step 817 the selected predictor indexed “i” 818 is extracted from the constructed list of predictors.
  • this predictor is the last predictor added in the constructed list 814 .
  • the decoding method involves taking the last predictor of the constructed list 814 and rather than selecting from a complete set of predictors comprising, generally, a number of predictors greater than i the predictor at the position given by the motion vector predictor index “i”.
  • a complete set of predictors comprising, generally, a number of predictors greater than i the predictor at the position given by the motion vector predictor index “i”.
  • FIG. 8 is a flow chart illustrating steps of a general encoding process in which one or more embodiments of the invention may be implemented.
  • step 601 the number of predictors in a predictor set is determined according to the data which comes from the current slice in order to provide the number of predictors 602 .
  • RD rate distortion
  • the encoder may derive all the predictors in the predictors set to give the best coding efficiency since all the coding possibilities may be estimated at the encoder side.
  • FIG. 9 is a flow chart illustrating steps of an encoding process in which embodiments of the invention may be implemented.
  • module 501 is the same as module 318 of FIG. 5
  • module 512 is the same as module 309 of FIG. 5 .
  • the step of derivation of motion vector predictors 504 generates the motion vector predictors set 505 by taking into account the current reference frame index 502 if needed (Inter mode). Then, a motion vector set generation process as will be described below can be applied in step 506 to the motion vectors set to produce a newly constructed list of x motion vector predictors or reduced motion vector predictors set 507 .
  • step 508 the number of predictors x (represented by reference 509 ) in this reduced predictor set 507 is determined. Then, the best predictor is selected with the RD selection criterion and its related index i 503 is received by the module of predictor index signalling. If the number of predictors 509 is higher than one, the index i of the best predictor 403 is converted in the module 510 to a code word 511 . This code word, if it exists, is then entropy coded in 512 .
  • the encoder complexity and encoding time may be minimised by restricting the amount of predictors derived.
  • this restriction may depend on several parameters. For example, the block size, the encoding mode Inter/Merge/Merge Skip can be taken into account to reduce the encoding complexity.
  • the number of predictors derived can evolve according to the encoding time already spent to encode the current frame.
  • the encoder can limit the number of predictors derived for all Inter modes. For example, only one predictor may need to be derived to obtain a compliant bitstream instead of deriving the whole set of predictors as is done in HEVC derivation processes of the prior art.
  • An early decision process may be implemented at encoder side.
  • the main advantage in applying such a process is that a predictor is derived only if that predictor needs to be tested.
  • the reduction in computational complexity results from the reduced number of predictors derived.
  • FIG. 10 An example of an encoding method implementing an early decision algorithm according to an embodiment of the invention is illustrated in FIG. 10 .
  • step 1002 the number of predictors in the current set is determined to provide a number of predictors 1003 . Then, the predictor counter variable “j” is initialized to the value 0 in step 1004 .
  • step 1005 the module derives the predictor related to the index “j”.
  • the decision module returns the value “no”
  • the motion vector number “i” 1010 is the predictor derived in step 1005 .
  • This predictor 1010 is then added to the constructed list of predictors.
  • the decision module and the module generating non-duplicate predictors use this constructed list to determine if generated predictor is a duplicate of a predictor already in the constructed list of predictors.
  • the motion vector predictor “j” 1010 is then used for a rate distortion computation in step 1011 .
  • the module 1012 checks if the RD cost for motion vector predictor j is inferior to a threshold. If it is, the current block is encoded with the current tested block size, the current tested mode and the predictor number “j” in step 1016 . Otherwise the variable “j” is incremented in step 1013 .
  • the module checks if the value of j has reached a maximum number of predictors. In the case where the maximum number of predictors has been reached, the encoder will proceed to test other coding possibilities; otherwise the algorithm will return to step 1005 to derive the current predictor number “j”.
  • the algorithm involves predetermining a threshold in terms of number of elementary operations.
  • This threshold can depend on an encoding and decoding complexity target. Moreover, this threshold can be dependent on the block size. Indeed, the derivation process of the motion vector predictors set has less impact in terms of number of operations per pixel for high block size than for low block size.
  • the threshold could be defined, for example by compromising between coding efficiency and the complexity.
  • FIG. 11 is a flow chart illustrating steps of an encoding algorithm according to this further embodiment of the invention.
  • a comparison between 2 motion vectors is equivalent to one elementary operation and the derivation of one predictor value is equivalent to one elementary operation.
  • the variable “operation counter” gives the number of operations at the current instant. The aim of this algorithm is to derive a list of predictors with a restricted number of operations.
  • step 1102 the module determines the number of predictors 1103 in the set.
  • the predictor counter variable “j” is initialized to a zero value in step 1104 .
  • step 1106 the module derives the value of the predictor indexed “j”. In this example, this derivation represents one elementary operation, so the variable “operation counter” is incremented.
  • the module in step 1108 returns the value “no”
  • the variable “operation counter” is incremented by the number of predictors in the constructed list ( 1121 ) which is equal to the variable “j” since this corresponds to the number of comparison operations between predictors to be performed. If this “operation counter” indicates a count value which is superior to the defined operation count threshold 1117 and if predictor number “j” is superior to 0, then the derivation process is stopped and the encoder proceeds to the next encoding step. Otherwise the predictor number “j” is added in step 1119 to the constructed list of predictors 1121 . Then, the predictor count variable “j” is incremented. In step 1105 , the module checks if predictor number “j” is higher than the maximum number of predictors in the set 1103 . If that is the case, the derivation process needs fewer operations than the defined threshold.
  • step 1108 If in step 1108 the module identifies that the current predictor “j” is a duplicate candidate, the variable “operation counter” is incremented by the value “j” in step 1110 . And in step 1111 the module obtains a motion vector value for the current predictor “j”. The variable “operation counter” is then incremented in step 1112 . Then, in step 1113 the module checks if the obtained motion vector predictor value is a duplicate candidate or not by comparing the obtained motion vector predictor j with previously obtained motion vector predictor in the constructed list 1121 .
  • step 1113 If decision step 1113 returns true, that the motion vector predictor is a duplicate, the variable “operation counter” is incremented by “j” and in step 1115 , the module 1115 checks if the value of the operation counter is higher than the operation count threshold. If not, the algorithm will return to step 1111 . Otherwise, the derivation process ends, then the encoder will proceed to the next encoding step 1116 .
  • FIG. 12 illustrates a set of motion vector predictors in HEVC coding.
  • the two spatial motion vectors of the Inter mode are chosen from among those blocks which are above and left of the block to be encoded including the above corner blocks and left corner blocks.
  • the left predictor is selected from among the blocks “Below Left” and “Left”. In this specific order, the following conditions are evaluated until a motion vector value is found.
  • the “left” predictor is considered as unavailable. In that case, it means that the related blocks were Intra coded or these blocks do not exist. It means that in a first step the neighbouring block has been checked to determine if this predictor is in the list or not. (The availability of the predictor does not depend on the value of predictor).
  • the “above” predictor is selected from among “Above Right”, “Above” and “Above left” in this specific order, with the same conditions as described above.
  • This last step provides a non-duplicate value.
  • the temporal motion predictor comes from the nearest reference frame in low delay configuration.
  • 2 motion vectors are considered for the bottom right block of the collocated block.
  • One is in the first list “L 0 ” and one in the second list “L 1 ”. If both motion vectors exist, the motion vector which has the shortest temporal distance is selected. If both predictors have the same temporal distance, the motion from “L 0 ” is selected.
  • the collocated motion vector selected is then scaled, if needed, according to its temporal distance and to the temporal distance of the encoded motion vector. If no collocated predictor exists, the predictor is considered as unavailable.
  • 2 collocated motion vectors can be considered. Both come from the future reference frame.
  • the motion vector which crosses the current frame is selected. If both predictors cross the current frame, the motion vector which has the shortest temporal distance is selected. If both predictors have the same temporal distance, the motion from the first list “L 0 ” is then selected. The collocated motion vector selected is then scaled, if needed, according to its temporal distance and to the temporal distance of the encoded motion vector. For all motion temporal motion vector checked, the same criterion could be used.
  • the temporal predictor is considered as available. If no bottom right collocated predictor exists or if this predictor is a duplicate predictor the following conditions are evaluated until a motion vector value different than the predictor left is found
  • the set of predictors generated can contain 1, 2 or 3 predictors.
  • the Merge mode is a particular form of Inter coding. Two modes are considered. The first one is the Merge Skip mode. In that case, only the index of a predictor (if needed) is transmitted in the bit stream. For the classical merge mode, the partitioning and their related texture residual (if needed) and their related motion vector predictors index are transmitted.
  • the Merge modes For both Merge modes, no motion vector residual is transmitted.
  • the Merge modes take into account the value of the reference frame index, the direction (Bi directional or uni-directional) and the list (with the uni-directional direction) of the motion vector predictors.
  • the Merge mode uses a motion vector predictor and its reference frame index, unless the predictor is a temporal predictor where these parameters are derived from spatial predictors.
  • Signalling of the index of the selected motion vector predictor depends on the result of the constructed motion vector predictor set described above with reference to FIG. 10 or 11 . Indeed, the amount of bits allocated to the signalling depends on the number of motion vectors remaining in the constructed set. For instance, if at the end of this algorithm, only one motion vector remains, no overhead is required to signal the motion vector predictor index, since the index can easily be retrieved by the decoder. Table 1 gives the codeword for each index coding according to the number of predictors after the suppression process.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)
  • Compression, Expansion, Code Conversion, And Decoders (AREA)
US14/123,941 2011-06-06 2012-06-05 Method and Device for Encoding a Sequence of Images and Method and Device for Decoding a Sequence of Image Abandoned US20140169476A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB1109450.5 2011-06-06
GB1109450.5A GB2491589B (en) 2011-06-06 2011-06-06 Method and device for encoding a sequence of images and method and device for decoding a sequence of image
PCT/EP2012/060601 WO2012168242A2 (fr) 2011-06-06 2012-06-05 Procédé et dispositif de codage d'une séquence d'images et procédé et dispositif de décodage d'une séquence d'images

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2012/060601 A-371-Of-International WO2012168242A2 (fr) 2011-06-06 2012-06-05 Procédé et dispositif de codage d'une séquence d'images et procédé et dispositif de décodage d'une séquence d'images

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US16/422,865 Continuation US11095878B2 (en) 2011-06-06 2019-05-24 Method and device for encoding a sequence of images and method and device for decoding a sequence of image

Publications (1)

Publication Number Publication Date
US20140169476A1 true US20140169476A1 (en) 2014-06-19

Family

ID=44343465

Family Applications (2)

Application Number Title Priority Date Filing Date
US14/123,941 Abandoned US20140169476A1 (en) 2011-06-06 2012-06-05 Method and Device for Encoding a Sequence of Images and Method and Device for Decoding a Sequence of Image
US16/422,865 Active US11095878B2 (en) 2011-06-06 2019-05-24 Method and device for encoding a sequence of images and method and device for decoding a sequence of image

Family Applications After (1)

Application Number Title Priority Date Filing Date
US16/422,865 Active US11095878B2 (en) 2011-06-06 2019-05-24 Method and device for encoding a sequence of images and method and device for decoding a sequence of image

Country Status (3)

Country Link
US (2) US20140169476A1 (fr)
GB (1) GB2491589B (fr)
WO (1) WO2012168242A2 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160269738A1 (en) * 2013-10-15 2016-09-15 Orange Method for encoding and decoding images, device for encoding and decoding images, and corresponding computer programmes
US20180249176A1 (en) * 2015-03-11 2018-08-30 Lg Electronics Inc. Method and apparatus for encoding and decoding video signal
CN110266316A (zh) * 2019-05-08 2019-09-20 阿里巴巴集团控股有限公司 一种数据压缩、解压方法、装置和设备
US11533470B2 (en) * 2017-01-16 2022-12-20 Industry Academy Cooperation Foundation Of Sejong University Method and apparatus for encoding/decoding an image signal

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2524476B (en) * 2014-03-14 2016-04-27 Canon Kk Method, device and computer program for optimizing transmission of motion vector related information when transmitting a video stream

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090304084A1 (en) * 2008-03-19 2009-12-10 Nokia Corporation Combined motion vector and reference index prediction for video coding
US20120082229A1 (en) * 2010-10-01 2012-04-05 Yeping Su System for nested entropy encoding
US20120128071A1 (en) * 2010-11-24 2012-05-24 Stmicroelectronics S.R.L. Apparatus and method for performing error concealment of inter-coded video frames
US20120163466A1 (en) * 2010-12-28 2012-06-28 Toshiyasu Sugio Image coding method, image decoding method, image coding apparatus, image decoding apparatus, and image coding and decoding apparatus

Family Cites Families (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0620050A (ja) 1992-07-03 1994-01-28 Matsushita Electric Ind Co Ltd 動画像信号の復号化装置と推定動きベクトル算出方法
WO1999041912A2 (fr) 1998-02-13 1999-08-19 Koninklijke Philips Electronics N.V. Procede et dispositif de codage video
US7327791B1 (en) 1999-02-22 2008-02-05 Mitsubishi Denki Kabushiki Kaisha Video decoding method performing selective error concealment and resynchronization
US6552673B2 (en) 2000-02-25 2003-04-22 Texas Instruments Incorporated Efficient table access for reversible variable length code decoding using a hash function
US20050207663A1 (en) 2001-07-31 2005-09-22 Weimin Zeng Searching method and system for best matching motion vector
US7787746B2 (en) 2001-10-23 2010-08-31 Thomson Licensing Fast motion trick mode using non-progressive dummy bidirectional predictive pictures
KR100492127B1 (ko) 2002-02-23 2005-06-01 삼성전자주식회사 적응형 움직임 추정장치 및 추정 방법
KR100474285B1 (ko) 2002-04-08 2005-03-08 엘지전자 주식회사 모션벡터결정방법
CN101631247B (zh) 2002-04-18 2011-07-27 株式会社东芝 运动图像编码/解码方法和装置
US7620106B2 (en) 2003-09-07 2009-11-17 Microsoft Corporation Joint coding and decoding of a reference field selection and differential motion vector information
US7577198B2 (en) 2003-09-07 2009-08-18 Microsoft Corporation Number of reference fields for an interlaced forward-predicted field
CN1225127C (zh) 2003-09-12 2005-10-26 中国科学院计算技术研究所 一种用于视频编码的编码端/解码端双向预测方法
CN100353768C (zh) 2003-11-26 2007-12-05 联发科技股份有限公司 在视频压缩系统中进行运动估测的方法及相关装置
US7676722B2 (en) 2004-03-31 2010-03-09 Sony Corporation Multimedia content delivery using pre-stored multiple description coded video with restart
CN101005620B (zh) 2004-09-03 2011-08-10 微软公司 为隔行扫描和逐行扫描视频编码和解码宏块和运动信息中的革新
CN1256686C (zh) 2004-09-15 2006-05-17 哈尔滨工业大学 一种运动估计方法和应用该方法的运动估计电路
US8073053B2 (en) 2004-09-22 2011-12-06 Panasonic Corporation Image encoding device that encodes an arbitrary number of moving pictures
EP1703736A1 (fr) 2005-03-14 2006-09-20 BRITISH TELECOMMUNICATIONS public limited company Estimation de mouvement globale
KR100736041B1 (ko) 2005-06-30 2007-07-06 삼성전자주식회사 에러 은닉 방법 및 장치
JP2007067731A (ja) 2005-08-30 2007-03-15 Sanyo Electric Co Ltd 符号化方法
JP2007074592A (ja) 2005-09-09 2007-03-22 Sony Corp 画像処理装置および方法、プログラム、並びに記録媒体
US7620108B2 (en) 2005-09-16 2009-11-17 Sony Corporation Integrated spatial-temporal prediction
US8879857B2 (en) 2005-09-27 2014-11-04 Qualcomm Incorporated Redundant data encoding methods and device
US8325822B2 (en) 2006-01-20 2012-12-04 Qualcomm Incorporated Method and apparatus for determining an encoding method based on a distortion value related to error concealment
JP5004150B2 (ja) 2006-02-24 2012-08-22 Ｋｄｄｉ株式会社 画像符号化装置
JP5188033B2 (ja) 2006-04-24 2013-04-24 株式会社日立製作所 記録再生装置、送出装置及び伝送システム。
CN101064849A (zh) 2006-04-29 2007-10-31 鲁海宁 动态图像编码方法、装置和计算机可读记录介质
US20080002770A1 (en) 2006-06-30 2008-01-03 Nokia Corporation Methods, apparatus, and a computer program product for providing a fast inter mode decision for video encoding in resource constrained devices
CN100576919C (zh) 2006-08-08 2009-12-30 佳能株式会社 运动矢量检测设备及运动矢量检测方法
CN101155311B (zh) 2006-09-27 2012-09-05 中兴通讯股份有限公司 一种视频通信中的视频码流错误检测和处理方法
TW200836130A (en) 2007-02-16 2008-09-01 Thomson Licensing Bitrate reduction method by requantization
CN101267567A (zh) 2007-03-12 2008-09-17 华为技术有限公司 帧内预测、编解码方法及装置
CN100542299C (zh) 2007-08-31 2009-09-16 广东威创视讯科技股份有限公司 视讯图像错误的掩盖方法
EP2048886A1 (fr) 2007-10-11 2009-04-15 Panasonic Corporation Codage de coefficients de filtre d'interpolation adaptatifs
CN101466036A (zh) 2007-12-21 2009-06-24 北京中电华大电子设计有限责任公司 基于avs的运动矢量预测流水并行设计方法
US20090268821A1 (en) 2008-04-29 2009-10-29 The Hong Kong University Of Science And Technology Block parallel and fast motion estimation in video coding
JP2010028221A (ja) 2008-07-15 2010-02-04 Sony Corp 動きベクトル検出装置、動きベクトル検出方法、画像符号化装置及びプログラム
US20100020877A1 (en) 2008-07-23 2010-01-28 The Hong Kong University Of Science And Technology Multiple reference frame motion estimation in video coding
CN101350927B (zh) 2008-07-29 2011-07-13 北京中星微电子有限公司 帧内预测选择最优预测模式的方法及装置
JP5401071B2 (ja) 2008-10-09 2014-01-29 株式会社Ｎｔｔドコモ 動画像符号化装置、動画像復号装置、動画像符号化方法、動画像復号方法、動画像符号化プログラム、動画像復号プログラム、動画像処理システムおよび動画像処理方法
US8295623B2 (en) * 2008-10-14 2012-10-23 France Telecom Encoding and decoding with elimination of one or more predetermined predictors
KR101590511B1 (ko) 2009-01-23 2016-02-02 에스케이텔레콤 주식회사 움직임 벡터 부호화/복호화 장치 및 방법과 그를 이용한 영상 부호화/복호화 장치 및 방법
CN101931803B (zh) 2009-06-26 2013-01-09 华为技术有限公司 视频图像运动信息获取方法、装置及设备、模板构造方法
KR20110008653A (ko) * 2009-07-20 2011-01-27 삼성전자주식회사 움직임 벡터 예측 방법과 이를 이용한 영상 부호화/복호화 장치 및 방법
US9060176B2 (en) 2009-10-01 2015-06-16 Ntt Docomo, Inc. Motion vector prediction in video coding
CN101860754B (zh) 2009-12-16 2013-11-13 香港应用科技研究院有限公司 运动矢量编码和解码的方法和装置
CN101777963B (zh) 2009-12-29 2013-12-11 电子科技大学 一种基于反馈模式的帧级别编码与译码方法
WO2011095259A1 (fr) * 2010-02-05 2011-08-11 Telefonaktiebolaget L M Ericsson (Publ) Sélection de vecteurs de mouvement prédits candidats
ES2779226T3 (es) * 2011-05-31 2020-08-14 Sun Patent Trust Procedimiento de descodificación de vídeo y dispositivo de descodificación de vídeo

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090304084A1 (en) * 2008-03-19 2009-12-10 Nokia Corporation Combined motion vector and reference index prediction for video coding
US20120082229A1 (en) * 2010-10-01 2012-04-05 Yeping Su System for nested entropy encoding
US20120128071A1 (en) * 2010-11-24 2012-05-24 Stmicroelectronics S.R.L. Apparatus and method for performing error concealment of inter-coded video frames
US20120163466A1 (en) * 2010-12-28 2012-06-28 Toshiyasu Sugio Image coding method, image decoding method, image coding apparatus, image decoding apparatus, and image coding and decoding apparatus

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160269738A1 (en) * 2013-10-15 2016-09-15 Orange Method for encoding and decoding images, device for encoding and decoding images, and corresponding computer programmes
US20180249176A1 (en) * 2015-03-11 2018-08-30 Lg Electronics Inc. Method and apparatus for encoding and decoding video signal
US11533470B2 (en) * 2017-01-16 2022-12-20 Industry Academy Cooperation Foundation Of Sejong University Method and apparatus for encoding/decoding an image signal
US11665337B2 (en) 2017-01-16 2023-05-30 Industry Academy Cooperation Foundation Of Sejong University Method and apparatus for encoding/decoding an image signal
CN110266316A (zh) * 2019-05-08 2019-09-20 阿里巴巴集团控股有限公司 一种数据压缩、解压方法、装置和设备

Also Published As

Publication number Publication date
GB2491589B (en) 2015-12-16
WO2012168242A3 (fr) 2013-01-31
WO2012168242A2 (fr) 2012-12-13
US20190281287A1 (en) 2019-09-12
US11095878B2 (en) 2021-08-17
GB201109450D0 (en) 2011-07-20
GB2491589A (en) 2012-12-12

Similar Documents

Publication Publication Date Title
US11968390B2 (en) Method and device for encoding a sequence of images and method and device for decoding a sequence of images
US10506236B2 (en) Video encoding and decoding with improved error resilience
US11095878B2 (en) Method and device for encoding a sequence of images and method and device for decoding a sequence of image
GB2492778A (en) Motion compensated image coding by combining motion information predictors

Legal Events

Date Code Title Description
AS Assignment

Owner name: CANON KABUSHIKI KAISHA, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LAROCHE, GUILLAUME;ONNO, PATRICE;REEL/FRAME:032274/0467

Effective date: 20131121

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION