基于系统Raptor码不等差错保护的图像压缩传输

Compressed Image Transmission Based on Systematic Raptor Codes with Unequal Error Protection

该文提出一种在无线信道上进行图像传输的方案。喷泉码具有码率无关性,无需反馈信道,降低了系统复杂度。然而,传统喷泉码存在译码效率低、信息恢复质量对噪声敏感的问题。该方案基于系统Raptor码,在信道条件理想的情况下无需译码,提高了译码效率;引入不等差错保护(UEP)特性,根据信息重要性进行码率优化,使系统在不同信道环境中具有更好的稳定性。实验结果表明,在二进制删除信道信道(BEC)下,与传统纠错码和LT码及采用等差错保护(EEP)的Raptor码相比,该方案可显著提高传输的可靠性,获得更好的图像恢复效果。

A scheme for image transmission over wireless channel is proposed. Being rateless, fountain codes could reduce system complexity and no feedback channel is needed. Traditional fountain code has a low decoding efficiency, and the quality of the recovered information is sensitive to noise. Based on systematic Raptor, this method can improve the decoding efficiency because decoding is not even needed in the ideal channel. With the introduction of Unequal Error Protection （UEP） characteristics, this scheme makes the bitrate optimized according to the importance of information, so that a better stability can be achieved at different channel conditions. The experiment results show that, compared with traditional error-correcting codes and Raptor with Equal Error Protection （EEP）, this scheme can greatly improve the transmission reliability and achieve better reconstructed image quality over Binary Erasure Channel （BEC）.