We present a computationally efficient demosaicing algorithm based on a luminance-chrominance model of the Color Filter Array (CFA) image. We show that the chrominance information can be estimated using simple low-pass filtering. This algorithm allows us to use separable recursive filters, which are particularly adapted for real-time processing. Moreover, while most of demosaicing algorithms are specific to a particular CFA (usually the popular Bayer CFA), our method can be applied to any CFA. We present a linear version of the algorithm and an adaptive extension.