摘要
彩色图像灰度化的一个重要目标就是尽量保持原始彩色图像的边缘特征.基于三角级数逼近的非线性全局映射灰度化方法虽能较好地保持颜色顺序,且在很多情况下也保持了特征区分度,但在某些情况下仍会丢失或模糊边缘特征.为此,基于三角级数混合多项式逼近的思路,提出了改进的非线性全局映射灰度化方法.首先在三角级数逼近的基础上继续引入参数t和t2组合成最终的混合逼近函数,当t和t2前面的系数均为0时即为传统的灰度化方法;然后同时优化三角级数、t和t2前面的系数,以增强灰度图像的边缘特征.实验结果表明,在传统方法丢失或模糊边缘特征的情况下,采用文中方法也可以保持较好的边缘特征.
One of the important goals for transforming a color image to a gray one is to try to save as more visual characteristics of the original image as possible. The nonlinear global mapping method utilizes the trigonometric series approximation method, and achieves good results in many cases. By introducing t and t2 to mix with the trigonometric series where t is the corresponding parameter, this paper presents an improved nonlinear global mapping method. When the parameters of t and t2 are zero, the new method is degenerated into the traditional one. The new method achieves the final result by simultaneity optimizing the parameters o{ trigonometric series, t and t2. Experiments show the obvious improvement of the new method, i. e. , even in the case that some feature is blurred or lost by using the traditional one, the new method can also achieve a fairly good result.
出处
《计算机辅助设计与图形学学报》
EI
CSCD
北大核心
2013年第10期1476-1479,1488,共5页
Journal of Computer-Aided Design & Computer Graphics
基金
国防基础科研重点项目
国家大学生创新创业训练计划项目(201210336009)
关键词
灰度化
全局映射
非线性映射
color - to- gray
global mapping
nonlinear mapping
