| 摘要 |
The present invention relates to a bipartite histogram equalization apparatus using a visual threshold value for maintaining an average brightness change rate of a video. The bipartite histogram equalization apparatus comprises: a histogram conversion unit obtaining an input histogram by receiving an input image (X), obtaining a brightness value to divide the input histogram, and a target average brightness value of the output image, calculating a bipartite probability density function with regard to a split brightness value, obtaining a visual threshold value and threshold-processing the bipartite probability density function, and calculating a modified probability density function by uniformly redistributing the probability of loss due to threshold processing the threshold-processed probability density function to the threshold-processed probability density function; and a histogram equalization unit obtaining a modified cumulative distribution function by accumulating the modified probability density function, obtaining a histogram equalization mapping function by using an output dynamic range determined with the modified cumulative distribution function and the target average brightness value of the output image, and then performing histogram equalization by using the histogram equalization mapping function. |
