颜色对比度增强的红外与可见光图像融合方法

针对红外与可见光彩色融合图像中目标与背景间的低对比度的问题,提出一种基于HSI空间颜色对比度增强的红外和可见光图像融合方法.首先对输入的可见光与红外图像进行直方图均衡和中值滤波加强处理,然后对加强的红外图像模糊阈值分割得到红外目标,最后把分割的红外目标图像和加强的可见光和红外图像在HSI空间的三通道线性融合和色彩传递,为了增强目标与背景间的颜色对比度,在色彩传递阶段, H通道的色彩传递方程中引入一个比例因子.实验结果表明:与其他算法相比,该方法得到的彩色融合图像热目标和低温物体与背景间的颜色对比度明显加强,同时背景的细节信息呈现白天类似的自然彩色,更加符合人眼视觉感知.     

一种新的视角可控的液晶显示仿真研究

在PVA显示模式的基础上,研究了一种新型的液晶显示视角切换技术。通过增大液晶分子在暗态下的倾斜角度控制暗态亮度,实现了宽视角下暗态低,显示对比度高;窄视角下暗态高,在相同白态亮度下,显示对比度低。实施可行性:在时序控制芯片系统(Timing Controling,Tcon)中烧录两版code,使用者根据不同环境下对宽窄视角的特性需求选择相应的显示模式,通过宽窄视角下分别采用不同的Tconcode编译驱动电压以实现宽窄视角的面板显示。模拟结果表明:宽视角显示上下左右视角达到80°以上,而窄视角显示上下左右视角均不足40°,从模拟结果看本文提供的宽窄视角显示方法是有效的。     

测量长期光辐射下人眼对比度敏感函数及模型

正常环境下研究得出的对比敏感度函数模型,在人眼受长时间高亮度电脑或手机显示屏光辐射(即视觉异常)时不再适用。文中基于正弦光栅的计算公式在Matlab中编程得到了实验所需的正弦光栅。由于在不同光谱功率分布下的对比敏感度值会有较大差别,实验基于LCD显示器得出视觉异常实验者在不同光谱功率分布(日光,灯光)下的对比敏感度值和CSF曲线。并通过非线性最小二乘法得出视觉异常时CSF模型。其结果表明,视觉异常时人眼最敏感空间频率和光学成像能力均发生了较大变化,且节能灯和显示屏等非自然光源与自然光源日光相比其光谱功率分布对人眼对比敏感度的影响最大。     

光电跟踪系统中扩展目标的成像对比度分析

分析了影响大气层内扩展目标成像对比度的主要因素,研究了整体倾斜校正对扩展目标对比度影响的数学关系,并分析了采用绝对差分算法提取整体相位倾斜的复杂度优化问题。采用快速倾斜镜对成像光束整体倾斜进行校正能够提高扩展目标的成像对比度,降低后端数字图像处理的难度,进一步减少目标识别和跟踪所需要的时间,对提高低对比度目标的光电跟踪效率具有参考意义。     

Crystallization kinetics of Sn40Se60 thin films for phase change memory applications

The crystallization kinetics of Sn₄₀Se₆₀ thin films has been successfully investigated using sheet resistance versus temperature measurements. Thermal evaporation was used to deposit the films on ordinary glass substrates. The crystallization temperature for Sn₄₀Se₆₀ thin film was found to be 156.6 ± 0.3 ℃. In the as-deposited state, the sheet resistance was found to be 195 MΩ, this value declined to 1560 Ω/口 upon annealing. The value of activation energy obtained from the Kissinger plot was 0.62 ± 0.07 eV. From the results obtained, Sn₄₀Se₆₀ is a promising alloy for PCM application because of its high electrical contrast, high crystallization temperature, and relatively high activation energy.     

Medical image enhancement algorithm based on NSCT and the improved fuzzy contrast

In order to solve the problem of noise amplification, low contrast and image distortion in the process of medical image enhancement, a new algorithm is proposed which combines NSCT (nonsubsampled contourlet transform) and improved fuzzy contrast. The image is decomposed by NSCT. Firstly, linear enhancement method is used in low frequency coefficients; secondly the improved adaptive threshold function is used to deal with the high frequency coefficients. Finally, the improved fuzzy contrast is used to enhance the global contrast and the Laplace operator is used to enhance the details of the medical images. Experimental results show that the proposed algorithm can improve the image visual effects, remove the noise and enhance the details of medical images. © 2015 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 25, 7–14, 2015     

结合基元对比度与边界先验的显著性区域检测

研究了对完成计算机视觉任务有重要作用的视觉显著性检测,考虑到单纯依靠对比度计算进行显著性检测具有一定的局限性,提出了一种结合基元对比度与边界先验信息的显著性区域检测算法。该算法通过Mean-Shift分割构造图像基元结构,以图像基元为基础,利用图像颜色和亮度两种特征获得基元对比度显著图,再利用图像边界先验条件得到边界显著图;为了突出显著性目标,采用一种新的融合方式将以上检测结果进行融合,最后对显著图像进行多尺度增强操作,以获得更加高质量的显著性图。在国际公开数据集上的实验表明,该算法与现有的较成熟的方法相比,基本符合人眼的主观判断,具有较高的精度召回率。     

Simultaneous contrast: Evidence from licking microstructure and cross-solution comparisons.

The microstructure of rats' licking responses was analyzed to investigate both “classic” simultaneous contrast (e.g., Flaherty & Largen, 1975) and a novel discrete-trial contrast procedure where access to an 8% test solution of sucrose was preceded by a sample of either 2%, 8%, or 32% sucrose (Experiments 1 and 2, respectively). Consumption of a given concentration of sucrose was higher when consumed alongside a low rather than high concentration comparison solution (positive contrast) and consumption of a given concentration of sucrose was lower when consumed alongside a high rather than a low concentration comparison solution (negative contrast). Furthermore, positive contrast increased the size of lick clusters while negative contrast decreased the size of lick clusters. Lick cluster size has a positive monotonic relationship with the concentration of palatable solutions and so positive and negative contrasts produced changes in lick cluster size that were analogous to raising or lowering the concentration of the test solution respectively. Experiment 3 utilized the discrete-trial procedure and compared contrast between two solutions of the same type (sucrose-sucrose or maltodextrin-maltodextrin) or contrast across solutions (sucrose-maltodextrin or maltodextrin-sucrose). Contrast effects on consumption were present, but reduced in size, in the cross-solution conditions. Moreover, lick cluster sizes were not affected at all by cross-solution contrasts as they were by same-solution contrasts. These results are consistent with the idea that simultaneous contrast effects depend, at least partially, on sensory mechanisms. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

肺硬化性血管瘤的CT影像学特点

Objective: The aim of the study was to analyze the CT morphology features of pulmonary sclerosing hemangiomas (PSHs) and improve the diagnosis ability of this disease. Methods: The 18 cases of pulmonary sclerosing hemangioma (PSH) confirmed by operation and histopathology from August 2002 to May 2009 were collected, including 17 females and 2 males, aged from 19 to 60 years old, with an average age of 43 years. All the cases underwent plain CT scan, among them,16 cases received enhanced CT scan. Results: The 18 cases had isolated mass. Mean long-axis diameter of these lesions was (2.7 ± 1.3) cm (range, 1.9-4.2 cm). Of all cases, 5 cases (27.8%) were round in shape, 9 cases (50%) were oval, 4 cases (22.2%) were lobulated, and 14 cases (77.8%) were smooth margin. The air meniscus sign was in 2 cases (11.1%), and the halo sign in 3 cases (16.7%). Two cases (11.1%) contained small nodular calcification, the remaining 16 cases (70%) were homogeneous density, the CT density of the masses ranged from 24-47 HU, and the mean value was 35 HU. Sixteen cases received enhanced scan, the welt vessel sign was in 8 cases (44.4%),1 case showed less enhancement, 5 cases showed marked homogeneous enhancement and 10 cases showed intense and patchy heterogeneous enhanced. The CT density of the enhancing masses ranged from 60-110 HU, the mean value was 35 HU, and the net enhancement value was 14-80 HU, the mean value was 55 HU. Conclusion: PSH should be considered in middle-aged female whose CT found that single round or oval pulmonary nodules, with smooth margin, or associated with the air meniscus sign, the halo sign, or the marked enhancement.