Pre-processor of the region-of-interest based H.264 encoder for low power application

As the state-of-the-art of the modern video compression standard, H.264 shows a high coding performance. Introducing the motion estimation method, it has ten times computation comparing to MPEG2. The high computational requirement makes it hard to implement on portable devices. According to the human visual system (HVS) research, human eyes can only focus on one area in a frame, which is called region-of-interest (ROI). This phenomenon gives a chance to code all macro blocks (MB) unequally. In this work a ROI detector is involved as a pre-processor of the encoder. Although the ROI corresponding the global information, the proposed design makes the detection processes pixel by pixel. It saves the memory to meet the limited hardware resource. The pre-processor itself do not cost much hardware and power, while according to the simulation result, in the system level the ROI based encoder can save 60% computation compare to the standard H.264 encoder design.