Video coding employing an image de-graining loop-filter

摘要

It is the particular approach of the present invention to remove film grain from those images which are used as reference images for a predictive encoding. In this manner the amount of the prediction error to be transmitted from the encoder to the decoder is reduced compared to conventional encoding schemes. While conventionally the prediction error has to compensate on the one hand the predicted film grain stemming from the reference images and on the other hand the film grain included in the current image, the present invention simplifies these tasks as the film grain from the reference images is removed in advance. This is achieved by including a de-graining filter into the decoding loop and storing film grain free reference images. Consequently, the prediction error only includes the film grain of the current image to be encoded and the coding efficiency is increased accordingly.