Patent ID: 8577167

Claim:
A non-transitory computer-readable medium that stores processor executable instructions of an image processing system, the image processing system comprising: an local variance estimator, for estimating each pixel of an input image signal to separately output a local variance value of each pixel of the input image signal, and generating a noise threshold according to the state of the local variance values; a noise detector, coupled to the local variance estimator, for determining whether a pixel of the input image signal indicates a noise or an image according to the noise threshold; and a spatial de-noise filter, coupled to the noise detector, for filtering out the pixels indicating noises to generate an output image signal; wherein the state of the local variance value is determined by the maximum local variance value of all the pixels or part of the pixels of the input image signal, and the average local variance value of all the pixels or part of the pixels of the input image signal; wherein the local variance estimator compares the maximum local variance value with the average local variance value to acquire a first ratio, and then compares the first ratio with a preset value to thereby use the comparison result to determine the noise threshold.