Relatively low dynamic range images or image partitions are converted into relatively high dynamic range images or image partitions that comprise reconstructed pixel values having a higher dynamic range than pixel values of the relatively low dynamic range images. Information relating to reconstructed pixel values of the relatively high dynamic range images and pixel values of the relatively low dynamic range images is collected. Prediction parameters are derived from the collected information. A predicted image or image partition is predicted from a relatively low dynamic range image or image partition based on the prediction parameters and comprises predicted pixel values having the higher dynamic range than pixel values of the relatively low dynamic range image or image partition.