基于PXI总线的远程测控系统

随着计算机和网络的迅速发展,以及人们对测试系统的精度、数据处理和资源共享要求的不断提高,基于网络的测控系统也被逐渐地应用到工程领域,本文介绍了一种基于PXI总线的远程测控系统,并讨论了组建的方法。     

Information loss recovery for JPEG2000 image transmission in an error-prone environment

Information loss recovery techniques are important for transmitting images over error-prone channels at the decoder. A novel error recovery scheme for JPEG2000 image is presented in this paper, which adopts different techniques for the lowest frequency coefficients and high frequency coefficients in the wavelet domain. The low-frequency recovery algorithm was implemented by adopting the watermarking technique and the packet structure of JPEG2000. The low-frequency eoefficients taken as the hidden data were extracted from the compressed bit stream, and then were embedded back into the bit stream itself prior to transmission. The embedded data were used to recover the information loss. High-frequency reconstruction was performed in bitplane base. The damaged bitplanes were recovered according to the correlation in the wavelet subband structure and by using the algorithm based on the horizontal and vertical edge detection. Experiments verified the effectiveness of these algorithms.     

基于结构信息分布的图像质量评估新算法

图像质量评估技术是图像处理领域里的一个重要研究课题。从图像结构信息分布出发提出了一种图像质量的客观评估新算法,分析了小波包变换对图像结构信息、噪声信号的影响,以及内在关系,在此基础上提出了通过小波包变换获取图像的平均结构信息能量及结构信息强度,将其作为评价图像质量的指标,建立了评估模型。实验结果表明,该评估模型能准确地反映图像的客观质量。