Method of reducing mosquito noise generated during decoding process of image data and device for decoding image data using the same

摘要

A device for decoding coded image data to generate decoded image data by applying inverse orthogonal transformation to each block into which the coded image data is divided includes a quantization-information detecting unit (5, 9) detecting block-quantization-step-size information indicative of quantization step sizes used for a given block, and a frequency-characteristic modifying unit (7, 7A) modifying high frequency components of the decoded image data for the given block based on the block-quantization-step-size information, the high frequency components having frequencies higher than a predetermined frequency. <IMAGE>