Abstract: The disclosure regards cross-component prediction and methods for deriving of a linear model for obtaining a first-component sample for a first-component block from an associated reconstructed second-component sample of a second-component block in the same frame, the method comprising determining the parameters of a linear equation representing a straight line passing through two points, each point being defined by two variables, the first variable corresponding to a second-component sample value, the second variable corresponding to a first-component sample value, based on reconstructed samples of both the first-component and the second-component; and deriving the linear model defined by the straight line parameters; wherein said determining the parameters uses integer arithmetic.

Abstract: A method of encoding a motion information predictor index, comprising: generating a list of motion information predictor candidates; when an Affine Merge mode is used, selecting one of the motion information predictor candidates in the list as an Affine Merge mode predictor; when a non-Affine Merge mode is used, selecting one of the motion information predictor candidates in the list as a non-Affine Merge mode predictor; and generating a motion information predictor index for the selected motion information predictor candidate using CABAC coding, one or more bits of the motion information predictor index being bypass CABAC coded.

Abstract: Motion vectors of a first reference frame are permitted to point to a plurality of further reference frames. A method of storing the motion vectors comprises, when a block of the first reference frame has two motion vectors (V2A, V2B) initially, selecting one of the two motion vectors, the non-selected motion vector not being stored. The selected motion vector may be scaled. This can reduce the motion vector memory size.

Abstract: A method of encoding a motion information predictor index for an Affine Merge mode, comprising: generating a list of motion information predictor candidates; selecting one of the motion information predictor candidates in the list as an Affine Merge mode predictor; and generating a motion information predictor index for the selected motion information predictor candidate using CABAC coding, one or more bits of the motion information predictor index being bypass CABAC coded.

Abstract: Motion vectors of a first reference frame are permitted to point to a plurality of further reference frames. A method of storing the motion vectors comprises, when a block of the first reference frame has two motion vectors (V2A, V2B) initially, selecting one of the two motion vectors, the non-selected motion vector not being stored. The selected motion vector may be scaled. This can reduce the motion vector memory size.

Abstract: 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 method comprising for said image portion: obtaining a number i of motion information predictors 808 of a second set of motion information predictors 814 taken from a first set of motion information predictors for decoding the image portion; generating said second set of motion information predictors 814 consisting of said number i of motion information predictors, wherein there are no duplicates among the i motion information predictors of said second set. A method and device for of decoding a bitstream, and a method and device for encoding a sequence of image including a method for deriving motion information of an image portion of an image predicted by motion prediction with respect to at least one reference image as described above.

Abstract: A method, device, and computer program for motion vector prediction in scalable video encoder and decoder. The method concerns the process to determine motion information predictor in the enhancement layer of a scalable encoding scheme also known as motion derivation process. The method comprises a correction of the position in the reference layer used to pick-up the more relevant motion information available due to the compression scheme. Accordingly, motion information prediction is improved.

Abstract: A method, device, and computer program for motion vector prediction in scalable video encoder and decoder. The method concerns the process to determine motion information predictor in the enhancement layer of a scalable encoding scheme also known as motion derivation process. The method comprises a correction of the position in the reference layer used to pick-up the more relevant motion information available due to the compression scheme. Accordingly, motion information prediction is improved.

Abstract: A set of spatial motion information predictors to be encoded is generated from among spatial motion information predictors respectively associated with predetermined image portions adjacent to an image portion to be decoded, one of which is situated above the image portion to be decoded. At least one condition is used to determine that a spatial motion information predictor is not includable in the set. At least one condition is a condition to exclude from the generated set of spatial motion information predictors a spatial motion information predictor that is a duplicate of another spatial motion information predictor. A temporal motion information predictor is not subjected to the duplicate exclusion condition used for the spatial motion information predictors and may be a duplicate of a spatial motion information predictor in the generated set.

Abstract: The present invention concerns a method and a device for encoding or decoding blocks of pixels in the process of encoding or decoding a video. It concerns more particularly methods to handle parallelization when using INTRA Block Copy mode of HEVC Screen Content extension. It is based on the control of the area available for providing predictor blocks in INTRA Block Copy mode. Accordingly, the implementation is simple in order to allow parallelized process.

Abstract: A set of spatial motion information predictors to be encoded is generated from among spatial motion information predictors respectively associated with predetermined image portions adjacent to an image portion to be decoded, one of which is situated above left of the image portion to be decoded. At least one condition is used to determine that a spatial motion information predictor is not includable in the set. At least one condition is a condition to exclude from the generated set of spatial motion information predictors a spatial motion information predictor that is a duplicate of another spatial motion information predictor. A temporal motion information predictor is not subjected to the duplicate exclusion condition used for the spatial motion information predictors and may be a duplicate of a spatial motion information predictor in the generated set.

Abstract: A set of spatial motion information predictors to be encoded is generated from among spatial motion information predictors respectively associated with predetermined image portions adjacent to an image portion to be decoded, one of which is situated left of the image portion to be decoded. At least one condition is used to determine that a spatial motion information predictor is not includable in the set. At least one condition is a condition to exclude from the generated set of spatial motion information predictors a spatial motion information predictor that is a duplicate of another spatial motion information predictor. A temporal motion information predictor is not subjected to the duplicate exclusion condition used for the spatial motion information predictors and may be a duplicate of a spatial motion information predictor in the generated set.

Abstract: A method, device, and computer program for motion vector prediction in scalable video encoder and decoder. The method concerns the process to determine motion information predictor in the enhancement layer of a scalable encoding scheme also known as motion derivation process. The method comprises a correction of the position in the reference layer used to pick-up the more relevant motion information available due to the compression scheme. Accordingly, motion information prediction is improved.

Abstract: The invention relates to the encoding or decoding of at least one portion of an image by predicting the at least one portion using at least one predictor, the at least one predictor being determined as a function of at least one reference image portion and as a function of values of a plurality of items of motion information. After having obtained a value of a first item of the plurality of items, a value of a second item is evaluated as a function of the obtained value of the first item, the second item being an item of the plurality of items and being distinct from the first item. Next, the at least one predictor is determined as a function of the at least one reference image portion and as a function of the first and second items.

Abstract: The present invention is related to video coding and decoding, in particular HEVC RExt that define a palette coding mode dedicated to the coding of screen contents. In improved palette coding modes according to the invention, when building a palette, each time a new pixel is added to the class a palette entry defines, the palette entry is modified to take the means value of the pixels belonging to such class. In other improved palette coding modes, a built palette is post-processed to substitute a palette entry with a close entry of a palette predictor PRED. In yet other embodiments, palette coding modes having different threshold values to drive the building of their respective palettes are successively tested to use the best one in terms of rate-distortion criterion.

Abstract: The disclosure regards cross-component prediction and methods for obtaining a chroma sample from an associated luma sample using a linear model with parameters. The parameters are derived from luma and chroma samples neighbouring the luma and chroma blocks considered. The luma samples are down-sampled to match chroma resolution. A competition between several luma down-sampling schemes is proposed wherein two 1-tap filters are competing. This reduces computational complexity at the encoder. Also a competition between several sample sets defining the neighbouring luma and chroma samples used for parameter derivation is conducted, wherein a competing sample set is an irregular sample set. The irregular sample set preferably comprises only samples from second lines next to respective first lines of outer neighbouring samples parallel and immediately adjacent to respectively the left boundary and the top boundary of the current block. This improves chroma prediction and thus coding efficiency.

Abstract: A method of providing a mode value representing a prediction mode of at least part of an image to be encoded, the image being composed of a plurality of processing blocks, each processing block being predictable by applying a prediction mode of a plurality M of available prediction modes, the method comprising: determining first data indicative of a first set of n most probable prediction modes, from the plurality M of available prediction modes, for predicting the said at least part of an image; determining, for the case where a most probable prediction mode is not used, second data representative of a second set of prediction modes of the plurality M of available prediction modes wherein the second set of prediction modes comprise a restricted number N of prediction modes of the M available prediction modes, the prediction modes of the second set being selected from the M available prediction modes according to a predefined condition.

Abstract: The invention relates to the encoding or decoding of at least one portion of an image by predicting the at least one portion using at least one predictor, the at least one predictor being determined as a function of at least one reference image portion and as a function of values of a plurality of items of motion information. After having obtained a value of a first item of the plurality of items, a value of a second item is evaluated as a function of the obtained value of the first item, the second item being an item of the plurality of items and being distinct from the first item. Next, the at least one predictor is determined as a function of the at least one reference image portion and as a function of the first and second items.

Abstract: The invention concerns a method and a device for processing a current pixel block of an image using a palette prediction mode according to HEVC RExt. The mode uses a current palette to build a predictor block of indexes to predict the current pixel block. The current palette comprises entries associating entry indexes with pixel values. The method comprises predicting the current palette from entries of two or more palettes that are palettes previously used to process blocks of pixels. A palette predictor may be used that is built from the two or more palettes, preferably from the last used palette for a coding unit in the current coding entity and from the previously used palette for which a flag bitmap indicates whether or not its elements have been copied into the last used palette. Accordingly, the coding of the palette mode is improved.

Abstract: The disclosure regards cross-component prediction and methods for deriving of a linear model for obtaining a first-component sample for a first-component block from an associated reconstructed second-component sample of a second-component block in the same frame, the method comprising determining the parameters of a linear equation representing a straight line passing through two points, each point being defined by two variables, the first variable corresponding to a second-component sample value, the second variable corresponding to a first-component sample value, based on reconstructed samples of both the first-component and the second-component; and deriving the linear model defined by the straight line parameters; wherein said determining the parameters uses integer arithmetic.