引入双边滤波器优化的彩色滤波阵列插值

基于彩色滤波阵列(CFA)的图像传感器在每个像素 位置获得三原色红(R)、绿(G)和蓝(B)中的一种分量 ,其缺失 分量需要根据周围像素插值得到。目前提出的许多种插值算法,绝大部分采用Bayer排列模 式。本文在色 差恒定假设基础上,提出一种基于双边滤波器的自适应Bayer模型插值算法,对G通道的估计采 用自适应滤波器进行插值,对R和B通道的插值采用双边滤波器。算法利用待插值像素 与不同距离像 素相关性不同的思想,根据图像边缘自适应设定滤波模板,能较准确估计G、B和R、G通 道之间的色差值。 实验结果表明,对比多尺度色差梯度算法和边缘强度滤波等算法,插值后的图像不仅 主观视觉, 且客观评价指标(彩色峰值信噪比,CPSNR)均优于这些算法。

Color filter array interpolation based on bilateral filter optimization

Single image sensor based on color filter array (CFA) only samples one color at each pixel coordinate. Reconstructing the full-color image,missing colors need to be interpolated acc ording to neighbor colors.Many methods have been developed to interpolate missing pixels in the CFA pattern,an d Bayer CFA pattern is the most commonly used structure.In this paper,we propose an adaptive algorithm using b ilateral filter based on the criterion of color difference constant.This algorithm uses adaptive filter for green channel interpolation and bilateral filter for red and blue channel interpolation.The proposed algorithm exploits the correlative information depending on both the color of neighbor pixels and the relative distance between neighbor pixels within an image. It can adaptively choose the filter template and improve the color difference be tween blue and green channels or red and green channels.Experimental results show that it outperforms the multiscale gradients and other recent interpolation methods in terms of both subjective vision and objective assessmen t (color peak signal noise ratio).