Patent ID: 8131103

Claim:
A method of enhancing details in an input image with input pixels having input pixel values being limited to a range, the method comprising: average filtering the input pixel values to obtain average brightness values, applying a luminance mask to the average brightness values to obtain a masked value corresponding to a particular one of the input pixels and being different for average brightness values in a sub-range of the range than for pixels outside the sub-range, detail filtering the input pixel values to obtain a detail value indicative for an amount of detail corresponding to the particular one of the input pixels, and applying a non-linear function to the input pixel values to obtain for at least one of the input pixel values a corresponding output pixel value, a gain of the non-linear function being dependent on both the masked value and detail value both determined for the particular one of the input pixels, wherein the gain is higher for an input pixel with input pixel values outside the sub-range than for an input pixel with input pixel values inside the sub-range, and wherein the gain is higher for an input pixel for which the detail value indicates more high frequency content in an image portion around the particular input pixel than for an input pixel for which the detail value indicates less high frequency content.