水声通信中的鲁棒图像编码研究

由于受各种因素的影响，水下声信道是一种传输差错率较高的信道。标准化的图像编码系统(例如JPEC；H．263，MPEG等)使用了相似的压缩技术，它们往往存在严重的错误扩散，甚至单个错误比特就可能破坏整幅图像，所以一般不适合作为水下声信道图像传输的编码方案。文章针对常用的图像编码的缺点，利用定长编码技术，提出了一种高鲁棒性的图像压缩方案。实验表明在压缩率1．25比特／象素时，压缩后的图像仍然保持了较好的质量，并且能够较好地抵抗信道误码，提高了水下声信道图像传输的质量。

Study on Robust Image Coding for Underwater Communications

Affected on many adverse factors, data are prone to errors over underwater acoustic channels. Standard image coding systems (e.g. JPEG, H.263, and MPEG) employ a range of similar compression techniques, many of which lead to substantial error propagation, so much as a single bit error can destroy an image. Therefore, the standard systems are not fit for underwater channels. This paper proposes a robust image coding, which adopts fixed length coding. The simulations show that the quality of the reconstructed images is satisfying when 1 25bits/pixel is achieved. At the same time, the proposed image coding can efficiently resist the error bits and improve the quality of images that are transmitted in underwater acoustic channels.