Picture enhancement in video and block-coded image sequences

We propose a sharpness enhancement technique for video and decoded image sequences. Basically, the enhancement is accomplished by adding overshoot to luminance edges in an unsharp masking-like way. However, the optimal amount of overshoot added for a high image quality depends on the local image statistics. For this purpose, controls are introduced, to improve the performances and to adapt the operator to moving sequences with different characteristics. Both spatial and temporal information is used to enhance details, avoiding blocking artifacts and noise.