Luminance dependent quantization

摘要

The present invention provides a method for encoding, a method for decoding, an apparatus for encoding and an apparatus for decoding a video signal. At the encoder side as well as at the decoder side, a quantization step size is determined for a local region of an image based on its luminance and/or the luminance of the neighbouring pixels. The local determination enables adaptive quantization depending on the image content. Employing the luminance of the image area and/or the neighbouring pixels for controlling the quantization step size further enables performing the control in the same way at the encoder and at the decoder without need for further signalling.