1. A method of image analysis of an image in a sequence of images to determine a cross-fade measure, comprising the steps of: for a plurality of picture information picture elements representing the image, determining first and second temporal picture information gradients associated with the picture element and comparing the first and second temporal picture information gradients associated with the picture element to determine whether the picture information gradient is substantially uniform; wherein the first temporal picture information gradient is determined between a current image and a second image of the sequence of images; and wherein, for each picture element, the second image is selected as the image within a range of candidate second images that has the maximum difference between the picture information of the picture element of said current image and the corresponding picture element of the candidate second image.