Improved post-processing method for use in an image signal decoding system

Claim 1

A method, for use in an image signal decoding system, for post-processing, on a pixel-by-pixel basis, decoded image data of a current frame from an image signal decorder included in the image signal decoding system, comprising the steps of: (a) storing the decoded image data of the current frame in a memory; (b) filtering target pixel data stored in the memory to provided filtered target pixel data, wherein the target pixel data represents a pixel value of a pixel to be filtered; (c) calculating an absolute difference value between an original target pixel data and the filtered target pixel data, wherein the original target pixel data represents non-filtered target pixel data included in the decoded image data; (d) updating the stored target pixel data with the filtered target pixel data if the absolute difference value is smaller than a predetermined threshold value; (e) repeating said steps (b) to (d) N times as long as the absolute difference value is smaller than the predetermined threshold value and updating the stored target pixel value with compensated target pixel data if the absolute difference value is equal to or larger than the predetermined threshold value, wherein the compensated target pixel data is provided by adding the original target pixel data and the predetermined threshold value if the original target pixel data is smaller than the filtered target pixel data and by subtracting the predetermined threshold value from the original target pixel data if the original target pixel data is greater than the filtered target pixel data; and (f) repeating said steps (b) to (e) for a next target pixel until all the pixels in the current frame are post-processed.