Method and apparatus for bandwidth-reduced image encoding and decoding

An image decoding apparatus comprising:

• a lossless compression unit that performs lossless compression on deblocked data on a window basis during decoding of encoded image data;
• a lossless compression controller that determines a relation between the deblocked data and losslessly compressed deblocked data and a size of the window;
• a cache controller that selects losslessly compressed deblocked data corresponding to reference data used for motion compensation or motion estimation from the losslessly compressed deblocked data, based on the determined relation between the deblocked data and the losslessly compressed deblocked data;
• a lossless compression reconstruction unit that decodes the selected losslessly compressed deblocked data to reconstruct the reference data;
• and
• a cache storage unit that stores the reconstructed reference data.

An image encoding method comprising:

• performing lossless compression on deblocked data on a window basis during encoding of image data;
• determining a relation between the deblocked data and losslessly compressed deblocked data and a size of the window;
• selecting losslessly compressed deblocked data corresponding to reference data used to perform motion compensation or motion estimation from the losslessly compressed deblocked data, based on the determined relation between the deblocked data and the losslessly compressed deblocked data;
• decoding the selected losslessly compressed deblocked data to reconstruct the reference data;
• and
• storing the reconstructed reference data in a cache buffer.

An image decoding method comprising:

• performing lossless compression on deblocked data on a window basis during decoding of encoded image data;
• determining a relation between the deblocked data and losslessly compressed deblocked data and a size of the window;
• selecting losslessly compressed deblocked data corresponding to reference data used to perform motion compensation or motion estimation from the losslessly compressed deblocked data, based on the determined relation between the deblocked data and the losslessly compressed deblocked data;
• decoding the selected losslessly compressed deblocked data to reconstruct the reference data;
• and
• storing the reconstructed reference data in a cache buffer.

A non-transitory computer readable recording medium having recorded thereon a computer program for executing an image encoding method comprising:

• performing lossless compression on deblocked data on a window basis during encoding of image data;
• determining a relation between the deblocked data and losslessly compressed deblocked data and a size of the window;
• selecting losslessly compressed deblocked data corresponding to reference data used to perform motion compensation or motion estimation from the losslessly compressed deblocked data, based on the determined relation between the deblocked data and the losslessly compressed deblocked data;
• decoding the selected losslessly compressed deblocked data to reconstruct the reference data;
• and
• storing the reconstructed reference data in a cache buffer.

A non-transitory computer readable recording medium having recorded thereon a computer program for executing an image decoding method comprising:

• performing lossless compression on deblocked data on a window basis during decoding of encoded image data;
• determining a relation between the deblocked data and losslessly compressed deblocked data and a size of the window;
• selecting losslessly compressed deblocked data corresponding to reference data used to perform motion compensation or motion estimation from the losslessly compressed deblocked data, based on the determined relation between the deblocked data and the losslessly compressed deblocked data;
• decoding the selected losslessly compressed deblocked data to reconstruct the reference data;
• and
• storing the reconstructed reference data in a cache buffer.