Abstract: An encoding method for a picture part encoded in a bitstream and reconstructed can involve refinement data encoded in the bitstream and determined based on at least one comparison of a version of a rate distortion cost computed using a data coding cost, a distortion between an original version of the picture part and a reconstructed picture part, and at least one other version involving one or more combinations of with or without a refinement by the refinement data, or a refinement either in or out of the decoding loop, or with or without a mapping or an inverse mapping.

Abstract: The present principles relates to a method and device for encoding an input video comprising a luma component and two chroma components. The method comprises: —reshaping of said input video by applying (610) piece-wise linear functions to the luma and chroma components; —encoding (620) the reshaped video into a bitstream; and —encoding (630) parameters representative of said piece-wise linear functions as side information; and the method is characterized in that reshaping of said input video further depends on a targeted range of a decoded reshaped video and the range of a reconstructed video after an inverse-reshaping is applied on the decoded reshaped video.

Abstract: A method for encoding a block of a picture is disclosed. The method comprises for at least one sample of the block and for one current component:—obtaining a prediction value;—determining a mapped residual value from a source value of the sample and from the prediction value responsive to a mapping function; and—encoding the mapped residual value into a bitstream; wherein the mapping function is derived to obtain at least one of a reduction of a bit cost of the bitstream for a given quality of reconstruction or an increase of quality of reconstruction for a given bit cost of the bitstream.

Abstract: The present disclosure generally relates to a method and device of converting a HDR version of a picture to a SDR version of this picture. The method is characterized in that it converts the HDR version to the SDR version of the picture according to: a first indicator that indicates the presence of color mapping parameters; a second indicator that indicates whether a device is configured to convert the HDR version to the SDR version of the picture by taking into account said color mapping parameters; and a third indicator that indicates whether converting without taking into account said color mapping parameters is inhibited.

Abstract: The inventors realized that representing HDR content using LDR content and HDR residual is not unproblematic. The invention therefore proposes representing HDR content using LDR content, LDR residual and global illumination data, instead. That is, it is proposed a method of encoding an HDR video of high dynamic range together with an LDR video, the LDR video providing a lower dynamic range depiction of the HDR video content, the method comprising using processing means for encoding one video of the LDR video and a further LDR video extracted from the HDR video independent from the other video of the LDR video and the HDR video and predictive encoding the other video using the one video as reference, and lossless encoding global illumination data further extracted from the HDR video. This has the advantage that prediction is more stable and globally optimal predictors are more easily found.

Abstract: A method for decoding a picture block is disclosed. The decoding method comprises: decoding decoded data, and information for identifying a reconstructed reference picture in a decoder picture buffer; reconstructing another reference picture from the identified reconstructed reference picture identified by the information and from the decoded data; replacing in the decoder picture buffer the reconstructed reference picture identified by the information with the another reference picture; and reconstructing the picture block from the another reference picture.

Abstract: The present principles relates to a method and device for encoding an input video comprising a luma component and two chroma components. The method comprises: —reshaping of said input video by applying (610) piece-wise linear functions to the luma and chroma components; —encoding (620) the reshaped video into a bitstream; and —encoding (630) parameters representative of said piece-wise linear functions as side information; and the method is characterized in that reshaping of said input video further depends on a targeted range of a decoded reshaped video and the range of a reconstructed video after an inverse-reshaping is applied on the decoded reshaped video.

Abstract: The inventors realized that representing HDR content using LDR content and HDR residual is not unproblematic. The invention therefore proposes representing HDR content using LDR content, LDR residual and global illumination data, instead. That is, it is proposed a method of encoding an HDR video of high dynamic range together with an LDR video, the LDR video providing a lower dynamic range depiction of the HDR video content, the method comprising using processing means for encoding one video of the LDR video and a further LDR video extracted from the HDR video independent from the other video of the LDR video and the HDR video and predictive encoding the other video using the one video as reference, and lossless encoding global illumination data further extracted from the HDR video. This has the advantage that prediction is more stable and globally optimal predictors are more easily found.

Abstract: The present disclosure generally relates to a method and device of converting a HDR version of a picture to a SDR version of this picture. The method is characterized in that it converts the HDR version to the SDR version of the picture according to: a first indicator that indicates the presence of color mapping parameters; a second indicator that indicates whether a device is configured to convert the HDR version to the SDR version of the picture by taking into account said color mapping parameters; and a third indicator that indicates whether converting without taking into account said color mapping parameters is inhibited.

Abstract: The inventors realized that representing HDR content using LDR content and HDR residual is not unproblematic. The invention therefore proposes representing HDR content using LDR content, LDR residual and global illumination data, instead. That is, it is proposed a method of encoding an HDR video of high dynamic range together with an LDR video, the LDR video providing a lower dynamic range depiction of the HDR video content, the method comprising using processing means for encoding one video of the LDR video and a further LDR video extracted from the HDR video independent from the other video of the LDR video and the HDR video and predictive encoding the other video using the one video as reference, and lossless encoding global illumination data further extracted from the HDR video. This has the advantage that prediction is more stable and globally optimal predictors are more easily found.

Abstract: The present disclosure generally relates to a method and device of converting a high-dynamic-range (HDR) version of a picture to a standard-dynamic-range (SDR) version of this picture. The method is characterized in that it converts the high-dynamic-range version to the standard-dynamic-range version of the picture according to: a first indicator (I1) that indicates the presence of color mapping parameters; a second indicator (I2) that indicates whether a device is configured to convert the high-dynamic-range version to the standard-dynamic-range version of the picture by taking into account said color mapping parameters; and a third indicator (I3) that indicates whether converting without taking into account said color mapping parameters is inhibited.

Abstract: In scalable video coding, Enhancement Layer (EL) pictures are usually predicted from decoded Base Layer (BL) pictures. When the EL pictures and the BL pictures are represented with different color spaces, color gamuts, transforming the decoded BL pictures, for example, to Inter-Layer Reference (ILR) pictures in the color space/gamut of the EL may improve the prediction. To accurately predict from the BL, the color space of the BL pictures can be partitioned into multiple octants, wherein each octant is associated with a respective set of color mapping function (CMF) parameters. The partitioning of color space may cause color discontinuity artifacts in the ILR pictures. In one embodiment, we avoid using a block of an ILR picture as a prediction block for the EL pictures if we determine that a color discontinuity artifact may exist in the block of the ILR picture.

Abstract: In order to take into account the local illumination variations in a scene, the invention proposes a method of compensating illumination variations in which distributions are determined for each block of an image (or view) and, in order to avoid a loss of the video coding efficiency, a distribution-based mapping function is automatically computed by a remote apparatus, such a decoder, from only information available at that apparatus when decoding a current block of the sequence of images. The present invention relates also to a method and device of encoding and/or decoding a sequence of images which comprises means configured to implement the method of compensating illumination variations according to the invention.

Abstract: The present disclosure generally relates to a method and device of converting a high-dynamic-range (HDR) version of a picture to a standard-dynamic-range (SDR) version of this picture. The method is characterized in that it converts the high-dynamic-range version to the standard-dynamic-range version of the picture according to: a first indicator (I1) that indicates the presence of color mapping parameters; a second indicator (I2) that indicates whether a device is configured to convert the high-dynamic-range version to the standard-dynamic-range version of the picture by taking into account said color mapping parameters; and a third indicator (I3) that indicates whether converting without taking into account said color mapping parameters is inhibited.

Abstract: A method for encoding an interlaced video comprising a sequence of alternating TOP and BOT fields is disclosed. The method for encoding comprises: producing a sequence of frames, each frame being determined from at least two consecutive fields, each field forming a rectangular region of the frame, encoding each frame of the sequence to produce an encoded video of the sequence of frames.

Abstract: In scalable video coding, Enhancement Layer (EL) pictures are usually predicted from decoded Base Layer (BL) pictures. When the EL pictures and the BL pictures are represented with different color spaces, transforming the decoded BL pictures, for example, to the color space of the EL may improve the prediction. To accurately predict from the BL, the color space of the BL pictures can be partitioned into multiple octants, wherein each octant is associated with a respective set of color mapping function (CMF) parameters. In one embodiment, we propose to estimate the CMF parameters for one particular octant based on not only samples from the particular octant but also samples from neighboring octants in order to reduce color discontinuity artifacts.

Abstract: A Video encoding method is disclosed that comprises: —receiving a video comprising a sequence of images comprising base layer images and enhancement layer images; —temporally filtering each base layer image into a temporally filtered image; —encoding the base layer images in order to produce base layer encoded video data and reconstructed base layer image; —encoding the enhancement layer images in order to produce enhancement layer encoded video data; —determining at least one parameter of a parametric filter for each reconstructed base layer image, such that applying the parametric filter with the parameter(s) to a version of the reconstructed base layer image produces a corrected base layer image which is closer to the temporally filtered image than the version of the reconstructed base layer image; —providing the base layer encoded video, the enhancement layer encoded video and the parameters.

Abstract: A method for decoding a picture block is disclosed. The decoding method comprises: decoding decoded data, and information for identifying a reconstructed reference picture in a decoder picture buffer; reconstructing another reference picture from the identified reconstructed reference picture identified by the information and from the decoded data; replacing in the decoder picture buffer the reconstructed reference picture identified by the information with the another reference picture; and reconstructing the picture block from the another reference picture.

Abstract: A method for decoding a picture block is disclosed. The decoding method comprises: reconstructing reference picture from another reference picture of a decoder picture buffer of a first layer of a multi-layered stream and from data decoded from a second layer of said multi-layered stream and storing said reference picture in a decoder picture buffer of said second layer, wherein said reference picture is indicated as not to be displayed; decoding a flag indicating that a subsequently decoded picture of the second layer is not using any inter-layer prediction; and reconstructing a picture block of said subsequently decoded picture at least from said reference picture.

Abstract: In order to take into account the local illumination variations in a scene, the invention proposes a method of compensating illumination variations in which distributions are determined for each block of an image (or view) and, in order to avoid a loss of the video coding efficiency, a distribution-based mapping function is automatically computed by a remote apparatus, such a decoder, from only information available at that apparatus when decoding a current block of the sequence of images. The present invention relates also to a method and device of encoding and/or decoding a sequence of images which comprises means configured to implement the method of compensating illumination variations according to the invention.