Non-linear scale-selection for image compression improvement obtained by perceptual distortion criteria

The effect of linear and nonlinear diffusions prior to the Joint Photographic Experts Group (JPEG) standard baseline compression is analysed and compared. We shall show that anisotropic diffusion acts as an adaptive filtering that extracts and preserves the important visual information, and it will be shown how it can be used as a preprocessing method for compression artefact reduction. The selection of the appropriate preprocessing parameters at a specified bit-rate greatly reduces the compression artefacts. The selection criteria were determined using a perceptual error metric based on a model of the human visual system.