基于JPWL的机载合成孔径激光雷达图像错误恢复方法研究

机载合成孔径激光雷达工作过程中,压缩图像的无线传输极易受到干扰甚至导致无法解码。本文在分析了机载合成孔径激光雷达图像形成过程和无线传输信道特点的基础上,针对JPEG2000无线图像压缩标准的层、块结构,提出了不等错误保护方法,在阻塞、无遮挡和遮蔽三种无线传输状态下,通过不同程度的纠错编码,实现了对主头、条带头、层数据三级不等错误保护。在白噪声和瑞利衰减模型下,仿真实现了BCH,RS,汉明三种编码并详细分析了不同编码以及有无感兴趣区域情况下图像的解码成功率及其图像质量。实验结果表明,通过本文中的不等错误保护方案,在近乎不增加带宽开销的基础上,大幅的提高了图像解码成功率;在有感兴趣区域情况下,提高了有利于识别的局部重构图像质量。

面向JPWL的无线信道图像健壮性传输技术的实现

对无线图像应用新标准JPWL所扩展的容错工具和方法的语法结构进行了深入细致的研究,结合无线信道性能的分析,给出了实现图像在无线信道健壮性传输的模拟环境和方案,实现了在无线信道中图像在易差错环境下的健壮传输。

Content-Based Image Unequal Error Protection Strategies for an Open Loop MIMO System

The paper deals with strategies for optimizing the transmission of JPEG2000 coded images over a MIMO quasi-static Rayleigh fading channel, by exploiting different available MIMO STBC (Space Time Block Codes), as well as the image content to be transmitted. The aim is to propose a link adaptation scheme based on the variable radio channel’s conditions, by establishing an UEP (Unequal Error Protection) scheme that leads to the best tradeoff between the robustness to errors and the image visual quality. Comparisons are made with the EEP (Equal Error Protection) case, in terms of the PSNR (Peak Signal to Noise Ratio) fidelity metric, as well as the subjective image quality.