Adaptive contrast enhancement apparatus and method

摘要

An adaptive contrast enhancement method, the steps include: calculating a probability density function based on pixel values of a plurality of pixels of an 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.

主权项

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.