Abstract: A sequence of frames is encoded in the following manner. An evaluation for respective zones in a frame is made whether a zone should be encoded in an intra-mode or in an inter-mode. A refresh scheme is applied that causes a set of zones in the frame to be forcibly encoded in the intra-mode, irrespective of the evaluation made. A specification of the refresh scheme is provided, which identifies the set of zones in the frame that are forcibly encoded in the intra-mode.

Abstract: A sequence of frames is encoded in the following manner. An evaluation for respective zones in a frame is made whether a zone should be encoded in an intra-mode or in an inter-mode. A refresh scheme is applied that causes a set of zones in the frame to be forcibly encoded in the intra-mode, irrespective of the evaluation made. A specification of the refresh scheme is provided, which identifies the set of zones in the frame that are forcibly encoded in the intra-mode.

Abstract: A video encoder encodes a sequence of frames so as to obtain an encoded sequence of frames in the following manner. A frame buffer assembly provides, for a present frame to be encoded, a representation of a previously encoded frame. The representation results from lossy compression by the frame buffer assembly of a decoded version of the previously encoded frame. An encoding assembly encodes the present frame at least partially with reference to the representation of the previously encoded frame. The video encoder produces a data set constituting encoded video comprising the encoded sequence of frames. The data set includes, in association with the previously encoded frame, an indication on the lossy compression that has been applied by the frame buffer assembly for providing the representation of the previously encoded frame, which has served, at least partially, as a reference for encoding the present frame.

Abstract: A sequence of frames is encoded in the following manner. An evaluation on a frame-by-frame basis is made for at least a zone in a series of successive frames whether the zone should be encoded in an intra-mode or in an inter-mode. A refresh scheme is applied that frequently causes the zone to be forcibly encoded in the intra-mode for one out of several successive frames, irrespective of the evaluation made. The zone in the series of successive frames is quantized so that if, for a frame, the zone is forcibly encoded in the intra-mode and contrary to the evaluation that was made, the zone is quantized with a higher resolution than if the zone were encoded in accordance with the evaluation that was made in one of the following modes: the intra-mode and the inter-mode.

Abstract: An image processor processes an image having color pixels (R, G, B) arranged in a Bayer pattern. The image processor provides a de-correlated image composed of three types of components (Y, Cr, Cb). The image processor provides a component of the first type (Y) as a substitute for a pixel of the first type (G), whereby the component of the first type (Y) is a weighted combination of a cluster of pixels that includes the pixel of the first type (G) and neighboring pixels, wherein neighboring pixels of the second and third type (R, B) have an overall positive weighting factor corresponding to an overall addition of neighboring pixels of the second and third type (R, B) to the pixel of the first type (G). The image processor also provides a component of the second type (Cr) and a component of the third type (Cb) in similar fashion.

Abstract: A method of encoding a sequence of frames includes applying a decorrelating transform to respective frames in the sequence to obtain respective transformed frames having an entropy lower than that of the respective frames in the sequence and data compressing the respective transformed frames so as to obtain respective encoded frames with an amount of data that is less than that of the respective transformed frames. At least one portion of the frame is encoded in an inter mode and at least one other portion of the frame is encoded in an intra mode. Respective frame portions in the respective frames are encoded in the intra mode in a dispersed manner such that, while a frame portion in one of the respective frames is forcibly encoded in the intra mode, at least one other frame portion is not forcibly encoded in the intra mode.

Abstract: In encoding a sequence of frames, a linear transform, such as, for example a wavelet transform, is applied to the sequences of frames on a frame-by-frame basis. At least one portion of a linearly transformed frame thus obtained is encoded in the inter mode on the basis of a differential representation of the linearly transformed frame. The differential representation corresponds with a difference between, on the one hand, the portion of the linearly transformed frame and, on the other hand, a representation of a corresponding portion of at least one other linearly transformed frame. Data compression is then applied to the differential representation of the portion of the linearly transformed frame.

Abstract: The disclosure relates to a method for compressing in a packed data set a color image comprising color image samples arranged in a reference grid according to a sampling pattern, and comprising the steps of (a) performing a decorrelative transform providing component images, (b) performing a number of discrete wavelet decompositions on said component images and (c) forming packets in the packed data set by processing each consecutive line in the reference grid and each component and grouping all samples of said component in said line in one or more packets, and appending said one or more packets to the packed data set. The disclosure also relates to a device for compressing, a computer program for compressing, a method for decompressing, a device for decompressing, and a computer program for decompressing. The disclosure also relates to the packed data set produced by said method for compressing.

Abstract: The disclosure relates to a method for compressing in a packed data set a color image comprising color image samples arranged in a reference grid according to a sampling pattern, and comprising the steps of (a) performing a decorrelative transform providing component images, (b) performing a number of discrete wavelet decompositions on said component images and (c) forming packets in the packed data set by processing each consecutive line in the reference grid and each component and grouping all samples of said component in said line in one or more packets, and appending said one or more packets to the packed data set. The disclosure also relates to a device for compressing, a computer program for compressing, a method for decompressing, a device for decompressing, and a computer program for decompressing. The disclosure also relates to the packed data set produced by said method for compressing.

Abstract: An image processor processes an image having color pixels (R, G, B) arranged in a Bayer pattern. The image processor provides a de-correlated image composed of three types of components (Y, Cr, Cb). The image processor provides a component of the first type (Y) as a substitute for a pixel of the first type (G), whereby the component of the first type (Y) is a weighted combination of a cluster of pixels that includes the pixel of the first type (G) and neighboring pixels, wherein neighboring pixels of the second and third type (R, B) have an overall positive weighting factor corresponding to an overall addition of neighboring pixels of the second and third type (R, B) to the pixel of the first type (G). The image processor also provides a component of the second type (Cr) and a component of the third type (Cb) in similar fashion.

Abstract: In encoding a sequence of frames, a linear transform, such as, for example a wavelet transform, is applied to the sequences of frames on a frame-by-frame basis. At least one portion of a linearly transformed frame thus obtained is encoded in the inter mode on the basis of a differential representation of the linearly transformed frame. The differential representation corresponds with a difference between, on the one hand, the portion of the linearly transformed frame and, on the other hand, a representation of a corresponding portion of at least one other linearly transformed frame. Data compression is then applied to the differential representation of the portion of the linearly transformed frame.

Abstract: In a video encoder (100), a motion estimation module (102) identifies for a portion of a frame to be encoded, a similar portion in a reference frame. The reference frame is a decoded version of an already encoded frame. A reference frame compression module (104) independently encodes respective portions of the reference frame so as to obtain respective encoded portions of the reference frame. The respective portions of the reference frame that are independently encoded are at least as large as the portion of the frame to be encoded. A reference frame memory (108) temporarily stores the respective encoded portions of the reference frame as an encoded representation of the reference frame. A reference frame decompression module (105) decodes an encoded portion of the reference frame stored in the reference frame memory (108), so as to obtain a decoded version of the encoded portion of the reference frame.

Abstract: A method and a device compress a display stream wherein coefficients are grouped, for each group, the greatest coded line index (GCLI) is determined and only the GCLI lowest weight bits of the coefficients are copied into the output stream together with the value of the GCLI. The method and device provide a good compression efficiency together with a simple hardware.

Abstract: A method and a device compress a display stream wherein coefficients are grouped, for each group, the greatest coded line index (GCLI) is determined and only the GCLI lowest weight bits of the coefficients are copied into the output stream together with the value of the GCLI. The method and device provide a good compression efficiency together with a simple hardware.