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.