CPC H04N 19/136 (2014.11) [H04N 19/119 (2014.11); H04N 19/176 (2014.11); H04N 19/61 (2014.11)] | 16 Claims |
1. A method for decoding a coded data stream representative of at least one image, said image being split into blocks, wherein the method comprises the following acts performed by a decoding device, for at least one block of the image, referred to as a current block:
reading from the data stream a threshold value defining a block size,
determining whether a size of the current block is less than or equal to said threshold value,
if the size of the current block is less than or equal to said threshold value, decoding an item of information indicating a coding mode of the current block among a first coding mode and a second coding mode and reconstructing the current block according to the coding mode indicated by the decoded item of information, and
if the size of the current block is greater than said threshold value, reconstructing the current block according to the first coding mode,
the first coding mode corresponding to a coding mode according to which the current block is reconstructed using an inverse transform of a transformed prediction residue decoded for the current block, and the second coding mode corresponding to a coding mode according to which the current block is not reconstructed using an inverse transform of a transformed prediction residue decoded for the current block, but by:
scanning each pixel of the current block according to a scanning order, said scanning comprising, for said pixel of the current block:
obtaining a prediction of said pixel from another previously decoded pixel, said other previously decoded pixel belonging to said current block or to a previously decoded block of the image, and
reconstructing said pixel from the prediction of said pixel obtained and a decoded prediction residue associated with said pixel.
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