An Enhanced Prediction Method for All-Zero Block in H.264

During the process of H.264 encoding, after the operation of quantization, it will generate a lot of all-zero blocks. In this paper we analyses the feature of the coefficients of the 4×4 residual block after transformation, on that basis a new algorithm for predicting all-zero block is proposed. And then, we utilize the sum of absolute residual(SAD)of the block and obtain thresholds to predict the all-zero block. So we can avoid doing transformation, quantization, and other operations on them, thus reduce the computing time in encoding process. Finally we use the H.264 reference software on VC platform to simulate the method, and compare it with other methods which are involved in the paper. The simulation results show that our method have the prediction rate up to 95.1%, which is more effective than other methods. And at the same time, the loss of the image quality is less than 0.2dB, which can be ignored.