Perceptually adaptive quantization parameter selection

Abstract

A system (and a method) are disclosed for adaptively selecting quantization parameter for each region of input video signal to be encoded within a video processing system. The system includes a frame partition module, an edge feature detector, a macroblock adaptive quantization energy (AQEnergy) evaluator and a macroblock adaptive quantization parameter selector. The frame partition module partitions a frame of an input video signal into smaller blocks of pixel data. The edge feature detector generates an edge direction histogram for each block to be encoded. The macroblock AQEnergy evaluator receives the edge direction histogram of the block, calculates the AQEnergy of the block and generates the adaptive quantization score (AQScore) of the macroblock. The macroblock adaptive quantization parameter selector selects an appropriate macroblock quantization parameter corresponding to the macroblock AQScore by a combination of programmable scaling and threshold logic.