由于物理结构的限制，单CCD图像传感器在每个像素位置上只能采集一个颜色分量，其余两个颜色分量只能通过插值的办法得到。提出一种在色差空间进行插值的算法，利用具有比例线性关系的局部颜色特性和局部协方差求得最小均方误差意义下的最优插值系数。所获取的该插值系数具有边缘细节保持性，同时色差空间的插值又考虑了不同颜色分量间的耦合性，因而有效地抑制了图像边缘的模糊和颜色失真。实验结果表明，该算法可获得高质量的插值图像。

Due to the physical structure of a single-chip CCD image sensor, there is only a single color component at each pixel position. To recover the full color images, an image interpolation or de-mosaicking is required to reconstruct the other two color components. In this paper, a novel image interpolation algorithm in the color difference space is proposed. By using the ratio linearity property of local color and the local covariance, the optimal MMSE interpolation coefficients are obtained. These coefficients can preserve the edge details of the interpolated images.The interpolation in the color difference space takes into account the correlations between color components, so that the edge blurring and color distortion can be dramatically reduced. Compared with some of the state-of-the-art methods, experiment results demonstrate that the interpolated images using the proposed algorithm are of good quality.