| 摘要 |
<p>A method for encoding a video sequence, comprising at least one frame having plural blocks of pixels, comprises: determining a frame merit (e.g. determined based on a fixed relationship between luminance frame and colour frame distortions) and a distortion at the frame level such that a video merit (e.g. using peak-signal-to-noise ratio), computed based on the distortion and frame merit, corresponds to a target video merit; determining, for each block of the plurality, a block merit for the concerned block based on the frame merit; transforming, pixel values for the block into a set of coefficients each having a coefficient type; selecting coefficient types based, for each coefficient, on an initial coefficient type encoding merit and on the block merit for the concerned block (e.g., if the coefficient type merit is greater than the block merit); quantizing the selected coefficients into quantized symbols; and encoding the quantized symbols. A broadly equivalent decoding method is also proposed. Further methods are also disclosed that give variations in the manner in which the frame merit is determined.</p> |
