Patent ID: 9582866
Date: 2017-02-28
CPC Classifications: G06T

Claim:
1. An adaptive contrast enhancement method to adjust contrast of an image of an input image signal, comprising: calculating a probability density function based on pixel values of a plurality of pixels of the input image signal; dividing the plurality of pixels into one of a plurality of low-brightness sets and high-brightness sets according to the pixel values of the plurality of pixels, wherein a part of the plurality of pixels with pixel values below one of a plurality of delimiting values are allocated to the low-brightness set and a part of the plurality of pixels with pixel values above the delimiting value are allocated to the high-brightness set; determining a mapping function according to the probability of the plurality of pixels in the low-brightness set and the probability of the plurality of pixels in the high-brightness set; and mapping the input image signal to an output image signal according to the mapping function, wherein the method is performed by an adaptive contrast enhancement apparatus; and wherein the image with adjusted contrast is displayed according to the output image signal.