公开(公告)号：US5862254A

公开(公告)日：1999-01-19

申请号：US819029

申请日：1997-03-17

Applicant: Young-taek Kim ,  Yong-hun Cho

Inventor： Young-taek Kim ,  Yong-hun Cho

IPC: H04N5/57 ,  G06T5/00 ,  G06T5/40 ,  G06K9/00

CPC classification number: G06T5/009 ,  G06T5/40

Abstract: A histogram-equalization method and circuit for enhancing an image signal represented by a predetermined number of gray levels is presented. The method calculates a cumulative density function and a mean level in a unit of a picture, and maps an input sample into a new gray level according to a transform function which is defined by use of the cumulative density function and the mean level. The method may also include a step of obtaining a compensated mean level by adding to the mean brightness level, so that the input sample is mapped into the compensated mean level according to the mean level. Thus, a brightness compensation may be carried out along with the contrast enhancement of the image.

Abstract translation: 提出了一种用于增强由预定数量的灰度级表示的图像信号的直方图均衡方法和电路。 该方法以图像为单位计算累积密度函数和平均电平，并且根据通过使用累积密度函数和平均电平定义的变换函数将输入样本映射到新的灰度级。 该方法还可以包括通过添加到平均亮度水平来获得补偿平均水平的步骤，使得输入样本根据平均水平被映射到补偿平均水平。 因此，可以与图像的对比度增强一起执行亮度补偿。