Device, system, and method for predicting residual data for intra and inter frame encoding of image or video data

A processor for encoding a data block of digital data, the processor is configured to:

• select an intra coding mode from among a plurality of intra frame encoding modes each having a different direction for extrapolating already encoded pixels adjacent to the data block, by:
• computing two or more direction gradient blocks, each representing changes in pixel values in a respective direction, wherein computing comprises applying a gradient filter in the respective direction to the set of pixels and a set of adjacent pixels which belong to one or more previously encoded data blocks;
• generating a 3D multi-directional gradient block by combining the two or more direction gradient blocks;
• calculating directional energy values of the data block, the values being associated with each of a predefined plurality of different mode directions, by, for each of the directional energy values, computing a scalar product of a mode direction vector and a vector of pixel value changes from the 3D multi-directional gradient block;
• and
• selecting a mode direction that is associated with a direction of minimum pixel value change by selecting a minimal directional energy value:
• compute a predicted intra frame encoding residual data for the data block associated with the selected mode based on the minimal directional energy value,
• compute inter frame encoding residual data for the data block associated with the difference between the pixel values of the data block in a current frame and one or more already encoded data blocks in one or more different reference frames,
• compare the intra frame encoding and inter frame encoding residual data, and
• compress the data block using intra frame encoding or inter frame encoding having the smaller residual data.

A system for encoding a data block of digital data, the system comprising:

• a mode decision unit to:
• select an intra coding mode from among a plurality of intra frame encoding modes each having a different direction for extrapolating already encoded pixels adjacent to the data block, by:
• computing two or more direction gradient blocks, each representing changes in pixel values in a respective direction, wherein computing comprises applying a gradient filter in the respective direction to the set of pixels and a set of adjacent pixels which belong to one or more previously encoded data blocks;
• generating a 3D multi-directional gradient block by combining the two or more direction gradient blocks;
• calculating directional energy values of the data block, the values being associated with each of a predefined plurality of different mode directions, by, for each of the directional energy values, computing a scalar product of a mode direction vector and a vector of pixel value changes from the 3D multi-directional gradient block;
• and
• selecting a mode direction that is associated with a direction of minimum pixel value change by selecting a minimal directional energy value;
• compute a predicted intra frame encoding residual data for the data block associated with the selected mode based on the minimal directional energy value,
• compute inter frame encoding residual data for the data block associated with the difference between the pixel values of the data block in a current frame and one or more already encoded data blocks in one or more different reference frames,
• compare the intra frame encoding and inter frame encoding residual data, and
• compress the data block using intra frame encoding or inter frame encoding having the smaller residual data;
• and
• a processor to compress the data block using intra frame encoding or inter frame encoding having the smaller residual data.