1. An imaging system comprising: processing circuitry configured to access image data of a plurality of pixels of an image, to provide a plurality of representations of the image data, to determine contrast difference between the representations of the image data for a respective one of the pixels, to identify the one of the pixels as being defective using the determined contrast difference, and to provide replacement image data for the one of the pixels identified as defective and which is different than the accessed image data for the one of the pixels identified as defective.