1. A filter configured to provide contour information from an array of pixel values representing an image, the array comprising a first and a second group of pixels, the first group of pixels representing at least a part of the image optically filtered with a filter having a first color, and the second group of pixels representing at least a part of the image optically filtered with one or more filters having one or more second colors, each pixel in the first group having a vertical and a horizontal neighboring pixel of the second group the filter comprising: a converter configured to convert the array of pixel values to a zero switched array, where the pixel values of the pixels in the second group are replaced by zero; and a contour filter configured to filter the zero switched array and output the contour information, the contour filter comprising: a definition generator configured to define a sub array in the array of pixels, for each pixel in the zero switched array, where the pixel to be filtered is positioned in a pre-determined position within the sub array; a first array of filter coefficients for use in the contour filter when the pixel to be filtered is a pixel from the first group of pixels, and a second array of filter coefficients for use in the contour filter when the pixel to be filtered is a pixel from the second group of pixels; a comparator configured to match noise of two separate filters comprising each of the first and the second filter coefficients; and a calculator configured to calculate a filtered pixel value.