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).