Correcting chrominance values based onTone-mapped luminance values

摘要

A tone mapping unit applies tone mapping to a block of pixel values. In each of a plurality of iterations, one or more lines of pixel values are processed based on information relating to pixel values of at least one previous line of the block which have been processed in at least one previous iteration. The information is used to determine one or more tone mapping relationships which is/are used to map the pixel values of the current line to tone-mapped pixel values. Furthermore, the information is updated based on the pixel values of the current line and stored for use in processing pixel values of a subsequent line of pixel values of the block in a subsequent iteration.