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为有效地提高地震资料的分辨率，提出了一种新的混合相位地震子波提取方法。相同振幅谱、不同相位谱的地震子波分别对应不同的最大和最小相位分量。在复赛谱域，遵照一定的规则，子波振幅谱可以分割为两部分，其分别对应于子波的最大和最小相位分量，分割比例的不同决定了子波不同的相位，由此可以得到最大相位子波、最小相位子波、零相位子波和一系列混合相位子波。根据地震记录信噪比谱的情况，设定地震记录的希望输出子波，对地震记录进行确定性子波反褶积。依据反褶积后地震记录方差模大小和分辨率情况，最终从一系列相同振幅谱不同相位谱子谱集合中确定理想的混合相位子波，通过确定性子波反褶积达到提高地震记录分辨率的目标。对理论合成地震记录和实际地震记录进行了子波提取实验，并利用提取的地震子波对地震资料进行了提高分辨率的处理，实验结果表明了该方法的正确性和有效性。     

Wavelet analysis based deconvolution to improve the resolution of scanning acoustic microscope images for the inspection of thin die layer in semiconductor

Scanning acoustic microscopy (SAM) is used as an important non-destructive test tool in semiconductor reliability evaluation and failure analysis. However, inspection of thin die layer has proven difficult as the reflected signals from the die top and bottom are superimposed. Conventional deconvolution techniques have been used for the improvement of time resolution in A-scan signal, however, they are not effective for SAM signal because the waveform of the reflected echo is quite different from the incident waveform due to the frequency dependent attenuation and the focal effect. In this paper, in order to overcome this difficulty, a new signal processing method, wavelet analysis based deconvolution technique is proposed. Its validity is approved by computer simulations and practical performances are demonstrated by experiments for the fabricated semiconductor sample.     

用频域法确定反卷积的最佳滤波参数

本文介绍了一种确定反卷积的最佳滤波参数的新方法。该方法的特点是，只需在频域就能确定滤波参数，因而节省了大量计算时间。     

测量误差对反卷积影响的分析及其滤波器的设计思想

本文分析了测量误差对反卷积稳定解影响的机理，并以此为根据提出了关于反卷积滤波器的设计思想，其设计公式与已广泛应用的设计公式相当一致。     

On-line X-ray focal spot assessment based on deconvolution using standard imaging devices

This article deals with micro-focus X-ray imaging in high resolution non-destructive testing applications. We present a new technique to assess on-line the focus shape using standard digital radioscopic devices. The focal spot is recovered using a deconvolution technique of the point spread function. A theoretical study based on radiation physics is carried out to determine the optimal material for the test object. We show that the minimum magnification and the detector's spatial cut-off frequency must be directly linked to the deconvolution regularization term. The proposed method is reliable, and does not required any assumption as regards the focus shape. Results are compared to former or existing standards, and to a Gaussian analytical model.     

Discrete constrained iterative deconvolution algorithms with optimized rate of convergence

In this paper, some new constrained discrete deconvolution algorithms based on an iterative equation are presented. The constraints are—the signal extent (signal support)—the positivity—the level bounds. The algorithms minimize either the error energy or a positive functional. The connections with previous works are studied. An experimental comparison of the algorithms convergence speed is studied with a synthetic sequence to be recovered. The restoration error and both the deconvoluted signal and its spectrum show clearly the performances of the algorithms and their ability to achieve a spectral extrapolation. The deconvolution from noisy data is investigated.     

Wavelet-based noise reduction for improved deconvolution of time-series data in dynamic susceptibility-contrast MRI

Dynamic susceptibility-contrast (DSC) MRI requires deconvolution to retrieve the tissue residue function R(t) and the cerebral blood flow (CBF). In this study, deconvolution of time-series data was performed by wavelet-transform-based denoising combined with the Fourier transform (FT). Traditional FT-based deconvolution of noisy data requires frequency-domain filtering, often leading to excessive smoothing of the recovered signal. In the present approach, only a low degree of regularisation was employed while the major noise reduction was accomplished by wavelet transformation of data and Wiener-like filtering in the wavelet space. After inverse wavelet transform, the estimate of CBF·R(t) was obtained. DSC-MRI signal-versus-time curves (signal-to-noise ratios 40 and 100) were simulated, corresponding to CBF values in the range 10–60 ml/(min 100 g). Three shapes of the tissue residue function were investigated. The technique was also applied to six volunteers. Simulations showed CBF estimates with acceptable accuracy and precision, as well as independence of any time shift between the arterial input function and the tissue concentration curve. The grey-matter to white-matter CBF ratio in volunteers was 2.4±0.2. The proposed wavelet/FT deconvolution is robust and can be implemented into existing perfusion software. CBF maps from healthy volunteers showed high quality.     

迭代频域反卷积滤波器的参数分析

本文首先分析了测量误差对反卷积稳定解的影响,然后介绍了几种能有效解决该问题的迭代频域反卷积滤波器,对其滤波函数的选取以及最佳滤波参数的确定展开讨论,并对它们的性能进行评述和比较。     

基于波前测量的图像复原技术综述

基于波前测量的图像复原技术成本低，性能优越，广泛应用于各种领域。介绍了这种方法的基本原理、关键技术和发展过程，与传统的自适应光学系统和线性复原技术比较，基于波前传感器测量的图像复原不仅降低了费用，而且图像恢复的性能较高。针对高速飞行器的图像恢复问题，分析了基于波前测量的图像复原技术的优缺点，并提出了改进方法。