A method and apparatus are provided for converting an interlaced video signal to a progressive scan signal. For each pixel in each missing line of a video field providing correlation data for each of set of possible interpolations between adjacent pixels to the pixel to be reconstructed. A confidence measure is then derived from the correlation data and from that confidence measure the interpolation scheme most likely to produce an accurate missing pixel is determined. The missing pixel is then interpolated using the selected interpolation scheme. In this process, the step of deriving a confidence measure comprises determining the number of maxima and minima in the correlation data and deriving the confidence measure in dependence on the number of maxima and minima so determined.