ENCODING APPARATUS, DECODING APPARATUS AND METHOD, AND COMPUTER PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an apparatus and method capable of enhancing a compression rate and image quality by revising a processing mode depending on a pixel distribution in an ADRC (Adaptive Dynamic Range Coding) processing.

SOLUTION: The encoding apparatus makes encoding by fixed length or variable length ADRC processing in response to a dynamic range in the unit of blocks resulting from applying area-division to image data being an encoding object and revises the encoding mode depending on the pixel distribution. For example, the processing apparatus sets a dynamic range (DR) and a minimum value (MIN) for minimizing a difference between an original pixel value and a decoded pixel value and residual data (err). Further, the processing apparatus varies the number of bits of the dynamic range. Moreover, a threshold value for a switching position of the number of quantization bits is revised and set in the variable length ADRC. Or the compression rate and the image quality can be enhanced by a method of assembly and division in blocks or the like by taking into account the pixel value distribution.

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