초록 ▼

A method for variable-length encoding of images includes a quantization step followed by a variable-length encoding step, whereafter the signals obtained are stored in a buffer memory. The quantization step used is computed on the basis of a feedback parameter, which is a decreasing function of the

A method for variable-length encoding of images includes a quantization step followed by a variable-length encoding step, whereafter the signals obtained are stored in a buffer memory. The quantization step used is computed on the basis of a feedback parameter, which is a decreasing function of the filling level of the buffer memory, and a feedforward parameter, which is a function of the quantity of information in the image. Advantageously, the feedforward parameter includes at least a multiplicative factor which is a decreasing function of the saturation of one of the chrominance components U or V in the current block or macroblock with respect to the rest of the image. An encoding device is also described.

대표청구항 ▼

[ What is claimed is:] [1.] A method of encoding images represented by digital signals organized in luminance and chrominance blocks grouped into macroblocks, comprising the steps of:quantizing the digital signals to produce quantized signals;variable-length encoding said quantized signals to produc

[ What is claimed is:] [1.] A method of encoding images represented by digital signals organized in luminance and chrominance blocks grouped into macroblocks, comprising the steps of:quantizing the digital signals to produce quantized signals;variable-length encoding said quantized signals to produce encoded signals; andstoring said encoded signals in a buffer memory,wherein a quantization step used in performing the quantizing step is computed on the basis of a feedback parameter which is a decreasing function of the filling level of the buffer memory, and a multiplicative correction factor in the form of a feedforward parameter which is a function of the quantity of information in the image currently being encoded, andwherein said feedforward parameter comprises at least one chrominance factor for a current block or macroblock, which is a decreasing function of the saturation of one of chrominance components U and V in the current block or macroblock, with respect to the rest of the image.