This invention relates to the reconstruction of a color plane in image mosaic data with correction for color aliasing artefacts, in particular where the image mosaic data is unequally weighted between different colors. The image mosaic is composed of a plurality of interleaved image pixels of at least three color values, each of which has a luminance value. Each row and column of the mosaic contains image pixels of at least two colors. An edge strength metric is assessed at locations in the image mosaic using at least two luminance values of the same color value to determine the strength of luminance changes and hence of detected edges at said locations. A low spatial frequency image is generated for each color value in which changes in luminance values are smoothed. The smoothing for each color value is in accordance with said edge strength metric so that smoothing at the locations of detected edges is inhibited. A high spatial frequency image is generated from the image mosaic, which combined with the smoothed low spatial frequency images for each color value results in a de-mosaiced color image with reduced or eliminated color aliasing along edges.