Image data coding and/or decoding system capable of high-efficient coding

摘要

An image data coding apparatus is provided comprising: first coding means (160) for coding a map signal indicative of position and shape of a content in a screen inputted for every square block of picture signals to be coded; resolution transform means (200) for performing orthogonal transform of said picture signals in accordance with said map signal to output an orthogonal transform coefficient; and second coding means (140) for coding said orthogonal transform coefficient derived by said orthogonal transform means, wherein said orthogonal transform means performs two-dimensional orthogonal transform of the picture signals of all the pixels with respect to blocks located inside of a content, and performs the orthogonal transform of only the signals of the pixels contained in the content with respect to the blocks containing a boundary portion of the content.