Abstract: A method of DRM protection for an image or a series of images or a succession of video frames, comprises: generating a reversible transform; applying the reversible transform to a source image; compressing the transformed image into a bitstream; and supplying the bitstream to a recipient for consumption. At the recipient the bitstream is decompressed and sent to the image display hardware with the transform still in place. A key is used to generate the inverse transform at the recipient and the inverse transform is then carried out in the image display hardware. An additional transform may be applied to the image following the inverse transform to offset pixels from an average value. Thus the source image itself is never exposed at the recipient although the image can be correctly viewed.