Methods and devices for encoding and decoding a data stream representing at least one image that disables post-processing of reconstructed block based on prediction mode

A method for encoding a data stream representative of at least one image, said image being split into blocks, wherein the method comprises the following acts implemented by a coding device for at least one block of the image, referred to as the current block:

• coding an item of information indicating a coding mode of the current block among at least a first coding mode and a second coding mode, the second coding mode being a coding mode according to which the current block is not coded by using a transform of a prediction residue of the current block, but by, for each 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,
• coding a prediction residue associated with said pixel obtained from the prediction of said pixel, and
• reconstructing said pixel from the decoded prediction residue associated with said pixel and the prediction of said pixel,
• coding the current block according to the coding mode indicated by the coded item of information,
• when the coding mode of the current block corresponds to a coding mode distinct from the second coding mode, applying at least one processing method to the reconstructed current block, and
• when the coding mode of the current block corresponds to the second coding mode:
• disabling applying said at least one processing method to the reconstructed current block for a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a neighbouring block in the image and if said neighbouring block is coded according to the second coding mode, and
• applying said at least one processing method to a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a reconstructed neighbouring block in the image and if said neighbouring block is coded according to a coding mode distinct from the second coding mode.

A decoding device for decoding an encoded data stream representative of at least one image, said image being split into blocks, wherein the decoding device comprises a processor configured, for at least one block of the image, referred to as the current block, to:

• decode an item of information indicating a coding mode of the current block among at least a first coding mode and a second coding mode, the second coding mode being a coding mode according to which the current block is not decoded by using an inverse transform of a transformed prediction residue of the current block, but by, for each 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,
• decoding a prediction residue associated with said pixel, and
• reconstructing said pixel from the prediction of said pixel obtained and the decoded prediction residue associated with said pixel,
• decode the current block according to the coding mode indicated by the decoded item of information,
• when the coding mode of the current block corresponds to a coding mode distinct from the second coding mode, apply at least one processing method to the reconstructed current block, and
• when the coding mode of the current block corresponds to the second coding mode:
• disable applying said at least one processing method to the reconstructed current block for a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a neighbouring block in the image and if said neighbouring block is coded according to the second coding mode, and
• apply said at least one processing method to a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a reconstructed neighbouring block in the image and if said neighbouring block is coded according to a coding mode distinct from the second coding mode.

An encoding device for encoding a data stream representative of at least one image, said image being split into blocks, wherein the encoding device comprises a processor configured, for at least one block of the image, referred to as the current block, to:

• code an item of information indicating a coding mode of the current block among at least a first coding mode and a second coding mode, the second coding mode being a coding mode according to which the current block is not coded by using a transform of a prediction residue of the current block, but by, for each 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,
• coding a prediction residue associated with said pixel obtained from the prediction of said pixel, and
• reconstructing said pixel from the decoded prediction residue associated with said pixel and the prediction of said pixel,
• code the current block according to the coding mode indicated by the coded item of information,
• when the coding mode of the current block corresponds to a coding mode distinct from the second coding mode, apply at least one processing method to the reconstructed current block, and
• when the coding mode of the current block corresponds to the second coding mode:
• disable applying said at least one processing method to the reconstructed current block for a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a neighbouring block in the image and if said neighbouring block is coded according to the second coding mode, and
• apply said at least one processing method to a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a reconstructed neighbouring block in the image and if said neighbouring block is coded according to a coding mode distinct from the second coding mode.

A non-transitory computer-readable medium comprising instructions stored thereon for implementing a decoding method for decoding a coded data stream representative of at least one image, when said instructions are executed by a processor of a decoding device, said image being split into blocks, wherein the instructions configure the decoding device to implement the following acts for at least one block of the image, referred to as the current block:

• decoding an item of information indicating a coding mode of the current block among at least a first coding mode and a second coding mode, the second coding mode being a coding mode according to which the current block is not decoded by using an inverse transform of a transformed prediction residue of the current block, but by, for each 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,
• decoding a prediction residue associated with said pixel, and
• reconstructing said pixel from the prediction of said pixel obtained and the decoded prediction residue associated with said pixel,
• decoding the current block according to the coding mode indicated by the decoded item of information,
• when the coding mode of the current block corresponds to a coding mode distinct from the second coding mode, applying at least one processing method to the reconstructed current block, and
• when the coding mode of the current block corresponds to the second coding mode:
• disabling applying said at least one processing method to the reconstructed current block for a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a neighbouring block in the image and if said neighbouring block is coded according to the second coding mode, and
• applying said at least one processing method to a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a reconstructed neighbouring block in the image and if said neighbouring block is coded according to a coding mode distinct from the second coding mode.

A non-transitory computer-readable medium comprising instructions stored thereon for implementing a coding method for encoding a coded data stream representative of at least one image, when said instructions are executed by a processor of a coding device, said image being split into blocks, wherein the instructions configure the coding device to implement the following acts for at least one block of the image, referred to as the current block:

• coding an item of information indicating a coding mode of the current block among at least a first coding mode and a second coding mode, the second coding mode being a coding mode according to which the current block is not coded by using a transform of a prediction residue of the current block, but by, for each 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,
• coding a prediction residue associated with said pixel obtained from the prediction of said pixel, and
• reconstructing said pixel from the decoded prediction residue associated with said pixel and the prediction of said pixel,
• coding the current block according to the coding mode indicated by the coded item of information,
• when the coding mode of the current block corresponds to a coding mode distinct from the second coding mode, applying at least one processing method to the reconstructed current block, and
• when the coding mode of the current block corresponds to the second coding mode:
• disabling applying said at least one processing method to the reconstructed current block for a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a neighbouring block in the image and if said neighbouring block is coded according to the second coding mode, and
• applying said at least one processing method to a pixel of the reconstructed current block if said pixel is located on a boundary of said reconstructed current block with a reconstructed neighbouring block in the image and if said neighbouring block is coded according to a coding mode distinct from the second coding mode.