A joint content adaptive Rate-Quantization model and region of interest intra coding of H.264/AVC

Assigning an appropriate Quantization Parameter (QP) to the Intra-coded frames is important to the video coding. In this research, a content adaptive Rate-Quantization (R-Q) model is presented to predict the bit usage of Intra-coded frames in H.264/AVC. The relationship between the QP of a macroblock and the block complexity is derived so that a suitable QP can be decided under a target bit-rate. Since the proposed model is built on macroblocks, Region of Interest (ROI) coding can also be achieved. By adjusting the QP value at the macroblock level, more bits can be assigned to the ROI to better maintain its perceptual quality. The experimental results show the feasibility of the proposed R-Q model.