Demosaicing Using Adaptive Filtering

Most digital still cameras acquire imagery with a colour filter array (CFA), sampling only one colour value for each pixel and interpolating the other two colour values afterwards. The interpolation process is commonly known as demosaicking. In general, a good demosaicking method should preserve the high-frequency information of imagery as much as possible, since such information is essential for image visual quality. The proposed method performs the demosaicing by using the following approach.1) Estimating the Luminance values at green-sample locations.2) Estimating the Luminance values at the red/blue sample locations.3) The estimated full-resolution luminance is taken as a reference to interpolate the sub-sampled color components.Frequency analysis of CFA samples indicates that filtering a CFA image can better preserve high frequencies than filtering each color component separately.