1. A method for predicting a high dynamic range image block with block-specific prediction data, the method comprising: receiving low dynamic range (LDR) image data for a target image block; receiving high dynamic range (HDR) image data for the target image block, the HDR image data comprising an HDR residual image block, a prediction scaling factor, and a prediction offset factor for the target image block; extracting an LDR image block from the LDR image data; scaling the LDR image block with the prediction scaling factor; offsetting the LDR image block with the prediction offset factor; and combining the scaled, offset LDR image block with the HDR residual image block to form an HDR image block corresponding to the target image block.