Abstract: The present invention relates to a method and a device for enhancing a digital image comprising samples or pixels. The method comprises: defining a patch of samples surrounding any given sample; computing distance values representing similarity between patches of a first sample and other samples to obtain a distance map; computing, using the distance map, weights to obtain a weight map; applying a filter enhancing high spatial frequencies to the weight map to obtain an enhanced weight map; filtering the first sample by averaging the samples using the enhanced weight map, to obtain an enhanced first sample. The invention provides a very efficient enhancement of the digital image since coherent structures that would usually not influence the enhancement of the image, are detected and made more significant thanks to the filtering of the weight map.

Abstract: To code a video sequence, the similarity is calculated (10) between a block of pixels to code of a current image of the sequence and blocks of pixels of a reference image and at least one motion vector per block of the sequence is determined on the basis of at least one similarity value calculated previously. Furthermore, for at least one block of pixels to code, a prediction (16) is determined of at least one motion vector from neighboring motion vectors that have already been calculated; a final motion vector is determined (18) from similarity values calculated previously for the block to code and on the basis of the predicted motion vector; and the block to code is coded (20) using the final motion vector.

Abstract: The invention relates to a method of identifying, from a plurality of sets of pixels, a set of pixels the values of which are intended to be used to determine the value of a target pixel. According to the invention: gradients are determined (step E20) for a plurality of pixels; a set of pixels consisting of the target pixel and at least two pixel subsets, a first pixel subset extending along a first direction and a second pixel subset extending along a second direction, is obtained (step E21); and the set of pixels is selected (step E24) as the set of pixels the values of which are intended to be used to determine the value of the pixel if the normal of the direction of the first subset does not intersect the gradient direction of any pixel within the first subset and if the normal of the direction of the second subset does not intersect the gradient direction of any pixel within the second subset.

Abstract: The invention concerns a method of concealing errors in at least one part of a current image (i) a sequence of images (4), characterized in that it comprises the following steps: comparing (S81) said at least one part of the current image (i) with at least one corresponding part of a previous image (i?1), and selecting (S83) a temporal error concealment method or a spatial error concealment method to be applied in said at least one part of the current image, according to the result of said comparison step and at least one item of information relating to the errors concealed in said at least one corresponding part of the previous image.

Abstract: In order to restore a video sequence consisting of a plurality of images each comprising at least one block of pixels: the value of the similarity between a block of pixels to be restored in the current image and a plurality of blocks of a reference image is calculated (10); the block of the reference image for which the value of the similarity is an extremum is determined; a similarity map is constructed (12) around the extremum; the similarity map is modeled (14) so as to obtain a model defined by a predetermined number of parameters; a local restoration filter is constructed (16) from the parameters of the model; and the pixels of the block to be restored are filtered (18) by applying to them the local restoration filter.