Patent ID: 7315652

Claim:
An image processing apparatus for decoding image data comprising frequency transform coefficients, the image data being divided to a plurality of tiles, each of which is in an encoding or decoding process, the image processing apparatus comprising: a detector which detects an existence status of a ROI set within said image data; a determiner which determines whether each tile is a ROI tile that is composed only of ROI coefficients, a non-ROI tile that is composed only of non-ROI coefficients, or a ROI boundary tile composed of both ROI coefficients and non-ROI coefficients based on said existence status of the ROI set detected by said detector; and a processor which performs a specific process for frequency transform coefficients of the ROI set and a non-ROI set within each tile for luminance component and color difference components, wherein said processor shifts the frequency transform coefficients to a lower bit side for luminance components and for color difference components for each tile determined to be a ROI tile, shifts the frequency transform coefficients to the lower bit side for color difference components for each tile determined to be a non-ROI tile, shifts the frequency transform coefficients to a lower bit side for the luminance components and for the color difference components corresponding to the ROI set for each tile determined to be a ROI boundary tile, and shifts the frequency transform coefficients to the lower bit side for the color difference components corresponding to the non-ROI set for each tile determined to be a ROI boundary tile.