改进的对块零树编码压缩方法对超光谱数据压缩

提出了对块零树的预测二值标量量化压缩编码方法，给出了压缩比公式，并应用此压缩编码实现了对超细光谱数据的压缩，该压缩编码方法既具有小波零树压缩编码高压缩比和宜于实时实现的特点，同时具有编码，解码速度快和易于实时传输等优点，实验结果表明，改进的对块零树编码压缩（IBBZTC）方法在不传输剩余误差的情况下，达到190倍的压缩比时，峰值信噪比仍然在30dB以上，压缩性能优于KL变换－静止图像压缩（KLT－JPEG），小波变换－矢量量化（WT－VQ），小波变换一零树矢量量化（WT－ZTVQ）和对块零树编码压缩方法。     

Parallel asynchronous focal plane array processing

A new approach to focal plane processing based on silicon injection mode devices is suggested. These devices provide a natural basis for parallel asynchronous focal plane image preprocessing. The simplicity and novel properties of the devices would permit an independent analog processing channel to be dedicated to every pixel. A laminar architecture built from arrays of the devices would form a two-dimensional (2-D) array processor with a 2-D array of inputs located directly behind the focal plane detector array. A 2-D image data stream would propagate in neuronlike asynchronous pulse coded form through the laminar processor. No multiplexing, digitization or serial processing would occur in the preprocessing stage. High performance is expected because approximately linear pulse coding has already been observed for input currents ranging over six orders of magnitude down to one picoampere with noise referred to input of about 10 femtoamperes. Very low power requirements suggest utility in space and in conjunction with very large arrays. Multispectral processing is possible because of compatibility with the cryogenic environment of high performance infrared detectors.     

Convergence Rates of Digital Diffusion Network Algorithms for Global Optimization with Applications to Image Estimation

Motivated by the recent developments in digital diffusion networks, this work is devoted to the rates of convergence issue for a class of global optimization algorithms. By means of weak convergence methods, we show that a sequence of suitably scaled estimation errors converges weakly to a diffusion process (a solution of a stochastic differential equation). The scaling together with the stationary covariance of the limit diffusion process gives the desired rates of convergence. Application examples are also provided for some image estimation problems.     

输出能量20kJ,脉宽10μs的爆磁压缩电流发生器实验研究

 8-6型爆磁压缩电流发生器由两级间接馈电式螺旋线圈及中心爆炸管电枢组成，前级进行能量放大，后级进行脉冲压缩及功率放大。多次实验表明：8-6型爆 磁压缩电流发生器能在5霩电感性负载上产生约100kA脉冲电流及超过20kJ能量，有效脉宽10μs。8-6型爆磁压缩电流发生器具有高输出能量及很好的稳定性，它在产生脉冲高电压应用领域具有广泛的前景。     

基于提升方案的CDF(1,5)整-整可逆双正交小波变换在渐进性无损图像压缩中的应用

讨论了基于双正交小波变换提升方案在图像压缩中的应用 ,研究了CDF( 1,3) ,CDF( 1,5 )双正交小波消失矩对图像压缩的影响。实验结果表明 ,在图像压缩中应尽可能选取具有较高消失矩的双正交小波 ,用CDF( 1,5 )双正交小波提升方案实现了基于整数运算的整 整可逆双正交小波变换 ,以及快速的、渐进性的直至无损图像压缩     

液氮冲击压缩特性的理论计算

 用修正的WCA理论计算了液氮冲击压缩至70 GPa的一次冲击Hugoniot数据。计算中引入与体系比容有关的分子离解因子，计算结果表明，在33GPa以上液氮体系发生的相变为分子离解相变，该过程对体系热力学状态有较大影响，分子离解是对冲击能量的吸收过程，导致体系冲击压力和温度增长率下降。     

基于小波变换的分水岭图像分割方法

图像分割技术在数字图像处理中占有重要地位.提出了一种基于小波变换的图像分割方法,有效地将小波分析、小波包分解与数学形态学中的分水岭方法相结合.首先,通过小波包对图像有效降噪,在一定程度上减少了分水岭方法的过分割现象.然后利用小波变换得到的梯度向量进行分水岭变换,有效保持边缘信息.实验结果证明该算法是可行的,与基于形态梯度的分割结果相比,得到了较好的分割效果.     

Probabilistic Approach to an Image Reconstruction Problem

This aim of this note is to present a probabilistic approach to an algebraic problem in image reconstruction. The role of probability theory is to identify the relevant variables that characterize the solutions, and to provide alternative variational methods of reconstruction.     

小波变换传递误差、尺度、加权量化对分层树剖分编码图象压缩质量影响的研究

详细研究了小波变换传递误差、尺度、快速Mallat算法加权量化对分层树剖分(SPIHT)编码图象压缩质量的影响,并给出了基于VC++的仿真结果,结果表明,小波变换尺度对图象压缩编码效果有明显的影响,通常要在大于4的尺度上作图象压缩编码才可以得到较好的压缩效果,不同的边界延拓,不同尺度的取整重构、加权量化对图象压缩效果的影响是不同的,恰当选取加权量化步长能达到更好的图象压缩效果,一般而言,同一尺度下随加权量化步长的增加,压缩效果变差.     

改进的JPEG-LS编码方法在飞行试验中的应用

本文提出了一种JPEG-LS编码改进方法,编码过程遵循JPEG-LS的无损模式。提出JPEG-LS编码器,该编码器能产生比其他的JPEG-LS编码器更高速率的编码效率。理论分析和实验表明本编码方法具有更高的编码效率和更低的误码率,适合应用于飞行试验中。