Error Resilience Technology Of Video Coding In The Wavelet Field

Video communication is very important in communication field with rapid development of multimedia technology. Information of image is so huge that it can not be transmitted or stored effectively without compression. Compressed data will be interfered inevitably during transmission due to the channel noise. It will lead to objectionable visual distortion. Redundancy information in image is eliminated with compression. It makes compressed data more sensitive to error and leads to further distortion. During transmitting video data in the noise channel, error resilience is indispensable. How to transmit video data effectively and reliably is becoming a key problem in multimedia application.In this paper, after introducing the theory of video coding and error resilience, study the methods of video coding and error resiling in the wavelet field are presented. Now almost video coding methods are based on DCT and the spatial motion compensation. There is obvious "blocking effect". Having the good characteristics of temporal-frequency localization and so on, wavelet transform is very suitable for describing nonstationary signal. Using the multi-resolution characteristic of wavelet coefficient, 3D_SPIHT coding can be realized. It does not need motion estimation coding wavelet coefficients with 3DSPIHT and reduces complexity of the algorithm, obtain good coding effect. In order to transmit video image reliably and increase the capability of error resilience, multiple description coding method is proposed. MDC_SPIHT don't decrease coding efficiency considering the characteristic of wavelet image. In addition forward error coding is adopted to correct some error. If some errors are not corrected, error concealment technology in decoder is employed considering human visual characteristic. According to the characteristic of wavelet coefficients the method of multi-direction interpolation is used to obtain good reconstruct image.The simulation experiment for this system indicates that the performance of coding and error resiling is improved significantly in the wavelet field. Video coding and error resiling in wavelet field is a good search aspect.