基于遥感图像频率域滤波的灰色线性中值去噪算法

结合频率域滤波去噪方法,对比低通滤波图像,按照灰色关联分析方法筛选出遥感图像中可能存在的噪声像元,优化噪声窗口灰度序列,并以此建立灰色线性模型,在参考传统中值滤波思想的基础上对含噪遥感图像进行去噪处理。大量仿真试验分析表明,该方法在处理脉冲噪声方面具有良好的去噪效果,且具有保持图像信息质量的特点。此外,试验中发现,采用该方法处理含有混合噪声的遥感图像时,根据具体图像含噪情况,合理地选取阈值,在一定程度上可以提高其削弱图像中混合噪声的水平。

基于频率和张量投票的图像去噪及仿真研究

结合人的视觉原理,基于图像局部梯度定义了一种图像频率,以图像频率代替全变分模型中的梯度。同时,把张量投票原理引入全变分模型,构造了一个图像结构显著性函数,代替变分模型中的拉格朗日乘子,根据图像不同区域的结构特征,去调节变分模型中正则项和保真项的作用,建立了一种基于频率的张量投票与全变分能量最小化结合的纹理图像去噪新方法。仿真实验数据表明,该模型比其他已有的全变分模型具有明显的抗干扰能力,能够更准确、精细地刻画图像边缘、特征结构和平滑区域,克服了其他全变分模型所产生的阶梯效应和过平滑现象,特别是对于纹理特征丰富和低信噪比的图像,在去除噪声的同时能较好地保持边缘及其他重要特征。

对电视机图像的最高频率论证的质疑

在电视教科书中,在对图像最高频率的论证上存在问题,从中选出有代表性的三个版本,通过对三个版本论证的评论,指出了各版本存在的不妥之处,对电视最高频率论证提出了质疑.

PAL制式下电视图像的最高频率不是6MHz,而是7.37MHz

原来的所有相关书刊在对电视图像最高频率的论证中存在错误,该文通过论证推出:我国电视机最高频率不是6 MHz,而是7.37 MHz.

联合图像—频率监督的图像超分辨率重建算法

针对现有单幅图像超分重建方法难以捕获图像中完备有效信息的问题,提出一种联合图像—频率监督的图像超分辨率重建算法,旨在利用多个域之间的互补信息,进而获得更完备的图像特征表示。首先通过分析图像像素转换到频域空间后的特性,根据其复数表征方式提出了一种新的频域距离监督损失,将频谱信息有效地应用到卷积神经网络的优化过程;然后通过分析频域中不同频带的表征特点,在频域距离损失基础上构建了频谱加权损失,并将其分别应用到低频和高频两个频带;最后结合图像域的监督,构成多个域的联合优化,取得良好的性能。在Set14、B100和Kodak三种公开数据集上进行了验证,结果表明:该算法的PSNR和SSIM分别达到了33.47 dB和0.9859,与几种图像超分方法相比取得了最好的性能。

一种区域型高频图像噪声的无损滤除方法

从构建图像各点强度变化的频率入手,借助领域知识和经验,展开对历史样本的针对性分析,提取出对区域型跳变噪声敏感的分类特征和分类阈值,再找出辨析两类交叠区中非噪声点的特征,设计两种特征的联合使用方案,成功实现了在不损伤图像中有效信息的前提下的区域型跳变且随时间移动缓慢的噪声的滤除。实验验证了算法的有效性和可靠性。

一种适合数字交换的多速率图像传输系统

介绍一种多速率图像通信系统，可直接作为ＩＳＤＮ的用户终端。该系统为分布式系统，有三个处理器，它们彼此独立工作，整个系统能双工工作，速率为Ｐ＊６４Ｋｂｉｔ／ｓ，Ｐ≤３０。

空间转换与自适应灰度校正的低照度图像增强

在低照度场景下采集的图像存在整体亮度偏低、对比度较差、细节信息丢失等问题,影响其在图像增强应用领域中的性能。为提高低照度成像质量,并使图像结构完整且纹理细节自然清晰,提出一种空间转换与自适应灰度校正的低照度图像增强算法。采用带有灰度校正的自适应压缩多尺度Retinex算法对原始图像进行处理,得到均衡化图像,避免在传统Retinex算法对图像进行全局处理时产生图像过亮或过暗的现象,通过空间转换方法处理获得的均衡化图像,分别得到频率域平滑图像和空间域锐化图像,以提高图像的整体亮度和对比度,从而保留图像中物体边缘的细节信息。在此基础上,采用多聚焦融合算法将原始图像、频率域平滑图像和空间域锐化图像进行融合,得到最终图像。实验结果表明,相比SSR、CLAHE、MBYC等算法,该算法的均值、方差、信息熵和平均梯度分别平均提升1.63%、0.89%、0.17%和1.91%,能有效提升低照度图像的亮度、清晰度和对比度,增强图像边缘信息和纹理细节信息。

基于人眼视觉特性的交互界面图像增强仿真

交互界面图像会受到电路噪声、传输损耗等因素的影响,使图像出现较多噪声,导致交互界面图像效果较差,设计一个基于人眼视觉特性的交互界面图像增强仿真方法。进行图像转换与图像去噪处理,将人眼视觉特性应用到图像处理中,计算亮度敏感特性与图像空间频率,进行图像灰度处理和细节处理,并将彩色恢复因子引入到图像处理中,实现交互界面图像增强。实验结果表明,所研究的基于人眼视觉特性的交互界面图像增强方法有效提高了图像的平均梯度与信噪比,提高了图像增强效果,并且增强后的图像噪声、均方误差也较低,满足方法预期设计目标。

基于深度学习的蘑菇种类识别算法研究

深度学习已广泛地应用于植物图像识别分类中.由于蘑菇图像的识别分类难度较大,针对如何提高识别模型的准确率和泛化能力,提出了单一背景下的蘑菇图像识别方法.针对传统的卷积神经网络中存在的空间冗余问题,采用了一种降梯度卷积训练模型,有效提高了蘑菇分类图像的识别性能.通过一个包含8123个样本的蘑菇数据集测试,降梯度卷积训练模型的平均耗费时间为0.985 s,第1张图像的平均命中准确率达到了91.6%,实验结果表明:降梯度卷积训练模型在单一背景、数据量较大的情况下,识别速度和准确率均优于传统的传统卷积神经网络.

静止图像传送装置TS100-MR200/MR100

引言静止图像传送装置是用电话线向远方传送电视图像的装置。它和传送活动图像的宽频带电视不同,传送一幅画面要用几十秒钟,在发送端和接收端分别需要图像存储器。在TS100-MR200系统中,发送端利用硒化镉视象管的高存储性能将摄像管本身作为图像存储器;接收端采用约有2兆比特容量的集成电路存储器,寿命长,能够得到清晰的图像。该系统现在由群马县高津户发电站使用。

256×256元MOS电阻阵驱动方法研究

基于MOS电阻阵的红外场景模拟器是半实物仿真系统中的关键设备。介绍了256×256元MOS电阻阵的结构和工作原理,研究了其驱动方法,详细介绍了驱动系统中图像数据传输电路和驱动控制逻辑电路的设计。驱动系统与电阻阵的联合实测结果表明:驱动系统的图像刷新频率达231.4帧/秒,单元像素灰度分辨率为16 bit。经实际使用,该驱动方法完全满足红外成像制导武器测试和半实物仿真的使用需求。

试论“图”的翻译辨析

本文较详尽地阐释了名词“图”在英汉汉英可逆对译中的普遍与特殊规律，翻译与写作技巧以及与该名词有关的相关学科中的组合或合成名词的用法、界说与界分，不无一定的理论指导和翻译实践意义。

The motion analysis of fire video images based on moment features and flicker frequency

In this paper, motion analysis methods based on the moment features and flicker frequency features for early fire flame from ordinary CCD video camera were proposed, and in order to describe the changing of flame and disturbance of non-flame phenomena further more, the average changing pixel number of the first-order moments of consecutive flames has been defined in the moment analysis as well. The first-order moments of all kinds of flames used in our experiments present irregularly flickering, and their average changing pixel numbers of first-order moments are greater than fire-like disturbances. For the analysis of flicker frequency of flame, which is extracted and calculated in spatial domain, and therefore it is computational simple and fast. The method of extracting flicker frequency from video images is not affected by the catalogues of combustion material and distance. In experiments, we adopted two kinds of flames, i. e. , fixed flame and movable flame. Many comparing and disturbing experiments were done and verified that the methods can be used as criteria for early fire detection.

可抑制工频干扰的8通道脑电采集系统及信号处理方法

针对现有通道数量较少的脑电采集设备受工频干扰严重的问题,设计并开发了一套可抑制工频干扰的8通道脑电采集系统及方法。首先,系统使用生物电信号采集前端ADS1299,采用集成陷波芯片UAF42,通过高速无线模块将8通道的脑电数据发送至上位机;其次,提出了频率谱分析法与频率扰动图像分析法相结合的脑电信号处理方法,分析了枕叶区两个电极的脑电信号,用频率扰动图像改进了频率谱显示的不足,以达到扩展脑电信号时域和频域共存的目的;再采集6位健康大学生的枕叶区单电极脑电信号并进行频率谱分析,验证了系统的稳定性。系统实验及处理方法表明:被试者闭眼时发现了α波节律;在8~14 Hz处α波谱峰值尤为明显,并且观测到在50 Hz频率处有明显的信号衰减;采用文中的处理方法实现了时域与频域共存的脑波图像,该系统及方法可以准确地采集处理人脑的自发脑电信号,减小了工频干扰对脑电信号的影响,可用于视觉诱发、睡眠监测以及运动想象等脑⁃机接口领域。

An ECT System Based on Improved RBF Network and Adaptive Wavelet Image Enhancement for Solid/Gas Two-phase Flow

Electrical capacitance tomography(ECT) is a non-invasive imaging technique that aims at visualizing the cross-sectional permittivity distribution and phase distribution of solid/gas two-phase flow based on the measured capacitance.To solve the nonlinear and ill-posed inverse problem:image reconstruction of ECT system,this paper proposed a new image reconstruction method based on improved radial basis function(RBF) neural network combined with adaptive wavelet image enhancement.Firstly,an improved RBF network was applied to establish the mapping model between the reconstruction image pixels and the capacitance values measured.Then,for better image quality,adaptive wavelet image enhancement technique was emphatically analyzed and studied,which belongs to a space-frequency analysis method and is suitable for image feature-enhanced.Through multi-level wavelet decomposition,edge points of the image produced from RBF network can be determined based on the neighborhood property of each sub-band;noise distribution in the space-frequency domain can be estimated based on statistical characteristics;after that a self-adaptive edge enhancement gain can be constructed.Finally,the image is reconstructed with adjusting wavelet coefficients.In this paper,a 12-electrode ECT system and a pneumatic conveying platform were built up to verify this image reconstruction algorithm.Experimental results demonstrated that adaptive wavelet image enhancement technique effectively implemented edge detection and image enhancement,and the improved RBF network and adaptive wavelet image enhancement hybrid algorithm greatly improved the quality of reconstructed image of solid/gas two-phase flow [pulverized coal(PC)/air].

掌握FCC的校验测试

虽然电缆工业执行性能的校验测试已经5年多了,但是,经常存在着测量误差。问题的一部分是对FCC的法规缺乏了解(或者说解释得不适当)。还有,经常缺乏测量过程的精确知识。只热心于使对用户的破坏为最小,而走不需要的、经常是不合理的捷径。在某些情况下,“好的工程实践”这一说法,已显得软弱无力。

Optimization of ultrasonic elastography by coded excitation and transmit-side multi-frequency compounding

To improve the quality of ultrasonic elastography, by taking the advantage of code excitation and frequency compounding, a transmitting-side multi-frequency with coded excitation for elastography （TFCCE） was proposed. TFCCE adopts the chirp signal excitation scheme and strikes a balance in the selection of sub-signal bandwidth, the bandwidth overlap and the number of sub-strain image based on theoretical derivation, so as to further improve the quality of elastic image. Experiments have proved that, compared with the other optimizing methods, the elastographyic signal-to-noise ratio（Re-SN） and contrast-to-noise ratio（Re-CN） are improved significantly with different echo signal-to-noise ratios （ReSN） and attenuation coefficients. When ReSN is 50 dB, compared with short pulse, Rc-SN and Re-CN obtained by TFCCE increase by 53% and 143%, respectively. Moreover, in a deeper investigation （85-95 mm）, the image has lower strain noise and clear details. When the attenuation coefficient is in the range of 0-1 dB/（cm.MHz）, Re-SN and Re-CN obtained by TFCCE can be kept in moderate ranges of 5〈Re-SN〈6.8 and 11.4〈Re-CN〈15.2, respectively. In particular, for higher tissue attenuation, the basic image quality cannot be ensured with short pulse excitation, while mediocre quality strain figure can be obtained by TFCCE. Therefore, the TFCCE technology can effectively improve the elastography quality and can be applied to ultrasonic clinical trials.

The Representation of a Broadband Vector Field

Compared to a scalar pressure sensor, a vector sensor can provide a higher signal-to-noise ratio （SNR） signal and more detailed intbrmation on the sound field. Study on vector sensors and their applications have become a hot topic. Research on the representation of a vector field is highly relevant for extending the scope of vector sensor technology. This paper discusses the range-frequency distribution of the vector field due to a broadband acoustic source moving in a shallow-water waveguide as the self noise of a surface ship, and the vector extension of the waveguide impulse response measured over a limited frequency range using an active source of known waveform. From theory analysis and numerical simulation, the range-frequency representation of a vector field exhibits an interference structure qualitatively similar to that of the corresponding pressure field but, being quantitatively different, provides additional information on the waveguide, especially through the vertical component. For the range-frequency representation, physical quantities that can better exhibit the interference characteristics of the wavegaide are the products of pressure and particle velocity and of the pressure and pressure gradient. An image processing method to effectively detect and isolate the individual striations from an interference structure was reviewed briefly. The representation of the vector impulse response was discussed according to two different measurement systems, also known as particle velocity and pressure gradient. The vector impulse response representation can not only provide additional information from pressure only but even more than that of the range-frequency representation.

A Novel Algorithm of Solving the Optimal Slope on Rate-distortion Curve for the Given Rate Budget

Rate-distortion optimization greatly improves the performance of compression coding system so that it pervades all of the source coding from an informationtheoretic standpoint and for the design of practical coding systems. For the case of rate-distortion optimization, Lagrange multiplier method provides the efficient and nearly optimal solution. In this paper, a fast and efficient algorithm is proposed to solve the optimal slope λ＊ of the rate-distortion curve at the given bit budget. Based on Lagrange multiplier method, the presented algorithm find λ＊ using the golden-ratio search. Compared with the Bisection method that only adapts to the system with the dense operational points on the rate-distortion curve, the proposed algorithm can be adapted to the system whether the operational points are populated densely or not. Thus it can be applied to both the wavelet coding system and the video coding standards such as H. 264, where Bisection method can not work well. In particular, the algorithm has been verified on the platform of the quadtree classified and trellis coded quantized （QTCQ） wavelet image compression system and the newest video coding standard H. 264. The experimental results are provided to demonstrate the efficiency of the algorithm. The proposed algorithm can improve the performance. A gain abour 0.6 - 0.7 dB can be achieved with the same rate in H. 264. In addition, it converges as fast as Bisection method, with almost the same ctinplexity.