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 luminance of pixels neighbouring to the local region. The local determination enables adaptive quantization depending on the image content. Employing the luminance of 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.