基于四元数色度距离的对比度保持灰度化方法  

Contrast maintaining graying method based on quaternion chromaticity distance

作　　者：赵宇晓 李剑飞 朱志亮 段润涛 黄晓生[1] Zhao Yuxiao;Li Jianfei;Zhu Zhiliang;Duan Runtao;Huang Xiaosheng(School of Software,East China Jiaotong University,Nanchang 330013,China;The State Key Laboratory of Computer Science,Institute of Software,Chinese Academyof Sciences,Beijing 100190,China)

机构地区：[1]华东交通大学软件学院,江西南昌330013 [2]中国科学院软件研究所计算机科学国家重点实验室,北京100190

出　　处：《南京理工大学学报》2021年第4期472-480,共9页Journal of Nanjing University of Science and Technology

基　　金：国家自然科学基金(61763011);中国博士后科学基金资助项目(2020M680697);江西省青年科学基金项目(20202BABL212006);江西省教育厅科学技术研究项目(GJJ190359);计算机科学国家重点实验室开放课题基金(SYSKF2102);江西省研究生创新专项资金项目(YC2019-S252)。

摘　　要：传统对比度保持灰度化方法采用欧氏距离计算彩色图像的对比度。这种方式只考虑了通道整体的相关性,没有考虑到通道之间的相关性,可能导致灰度化后的结果出现噪声或者细节丢失的情形。针对上述问题,利用四元数相关理论,提出基于色度面投影的四元数色度距离度量公式;利用该度量公式进一步提出基于随机差分的全局色度对比度度量方法和基于水平和垂直方向差分的局部对比度度量方法;利用该对比度度量方法构造对比度保持的目标函数;采用离散近似求解的思路来确定最优的用于灰度化映射的组合系数。实验结果表明,该方法具有较好的实时性,得到的灰度化结果能够更好地保持原彩色图像中的色彩细节对比度信息。The traditional contrast maintaining graying method uses the Euclidean distance to calculate the contrast of color images.This method only considers the overall correlation of channels,and does not consider the correlation between channels,which may lead to noise or loss of details in the grayscale results.To solve this problem,a quaternion chromaticity distance measurement formula based on chromaticity plane projection is proposed by using quaternion correlation theory.A global chromaticity contrast measurement method based on random difference is proposed by using the formula and a local chromaticity contrast measurement method based on horizontal and vertical difference is proposed.The contrast maintaining objective function is constructed by using the contrast measurement method,and the optimal combination coefficients for grayscale mapping are determined by using the ideal of discrete approximate solution.The experimental results show that the method has good real-time performance and the obtained grayscale results can better maintain the contrast information of color details in the original color image.

关 键 词：四元数 色度距离 色度对比度 彩色图像灰度化 对比度保持 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]