Decomposition of residual data during signal encoding, decoding and reconstruction in a tiered hierarchy

A method comprising:

• receiving a first set of adjustment values, the first set of adjustment values specifying adjustments to be made to a preliminary rendition of an image signal generated at a first level of quality to reconstruct a rendition of the image signal at the first level of quality;
• processing the first set of adjustment values;
• and
• deriving a second set of adjustment values based on the first set of adjustment values and on a rendition of the image signal;
• wherein the image signal is a plane of elements;
• wherein the second set of adjustment values pertain to reconstruction of a particular location in the plane;
• and
• wherein the second set of adjustment values are quantized depending on the particular location.

A non-transitory computer-readable storage medium having instructions stored thereon, the instructions, when executed by a processing device, causing the processing device to:

• receive an image signal at a first level of quality;
• produce a rendition of the image signal;
• produce a first set of adjustment values associated with the image signal at the first level of quality, the first set of adjustment values specifying adjustments to apply to a preliminary rendition of the image signal generated at the first level of quality to reconstruct a rendition of the image signal at the first level of quality;
• derive a second set of adjustment values to reconstruct the image signal at the first level of quality from the preliminary rendition of the signal at the first level of quality, the second set of adjustment values derived from:
• i) the first set of adjustment values, and ii) the rendition of the image signal.

A non-transitory computer-readable recoding-medium storing a bitstream which is generated by a video encoding method, the method comprising

• receive an image signal at a first level of quality;
• produce a rendition of the image signal;
• produce a first set of adjustment values associated with the image signal at the first level of quality, the first set of adjustment values specifying adjustments to apply to a preliminary rendition of the image signal generated at the first level of quality to reconstruct a rendition of the image signal at the first level of quality;
• derive a second set of adjustment values to reconstruct the image signal at the first level of quality from the preliminary rendition of the signal at the first level of quality, the second set of adjustment values derived from:
• i) the first set of adjustment values, and ii) the rendition of the image signal.