Patent ID: 8565531

Claim:
A method for detecting edge pixels in an image plane based on intensity and neutrality of a current pixel, when separating an image signal into a set of image planes, the method comprising: searching, via a min-max module, for a minimum value and a maximum value of a specified characteristic within at least one predefined neighborhood pixel window centered on the current pixel in the image signal, wherein the predefined neighborhood pixel window comprises the edge pixels; and detecting, via a dynamic threshold module, the edge pixels in the image plane based on predetermined criteria, wherein the predetermined criteria for detecting the edge pixels comprises determining whether: (a) a difference between the maximum value and the minimum value of the specified characteristic is greater than or equal to a first predetermined threshold, wherein the first predetermined threshold is based on the intensity and the neutrality of the current pixel in the image signal; and (b) (i) a difference between a current pixel value and the minimum value of the specified characteristic, or (ii) a difference between the current pixel value and the maximum value of the specified characteristic is greater than or equal to a second predetermined threshold, wherein the second predetermined threshold is based on the intensity and the neutrality of the current pixel in the image signal, wherein the specified characteristic within at least one predefined neighborhood pixel window centered on the current pixel is at least one selected from a luminance value of a luminance channel, a chrominance value of a first chrominance channel, and a chrominance value of a second chrominance channel, and wherein the neutrality of the current pixel is dependent on the chrominance value of the first chrominance channel, and the chrominance value of the second chrominance channel.