Method and device for decoding image data

摘要

A device for decoding coded image data divided into a plurality of blocks so as to generate decoded image data by applying an inverse orthogonal transformation to each block of the plurality of blocks includes a quantization-information detecting unit (5) detecting block-quantization-step-size information indicative of quantization step sizes used for the plurality of blocks. The device also includes a variable-gain-low-pass filter (7) reducing high frequency components of the decoded image data in a predetermined proximity of borders of the plurality of blocks based on the block-quantization-step-size information, the high frequency components having frequencies higher than a predetermined frequency. <IMAGE>