Compression of partially masked image data

摘要

A method of coding an image, that includes a background image coded as a plurality of image coefficients and a coded foreground image, comprises:
cancelling any image coefficients associated with spatial areas occupied by the foreground image;
reconstructing image data in both image areas from remaining coefficients;
correcting image data for the reconstructed image data in the background image area; and
coding new image coefficients from the reconstructed image data.