微纳尺度材料内耗测量系统的设计与实现

提出了一种非接触式的内耗测量方法。通过对碳纤维材料试样进行交变静电激发,在显微系统下记录强迫振动过程的高帧率图像,完成了微纳尺度材料内耗测量系统的设计。实验结果表明该系统能实现低频和高频内耗的非接触式测量,测量频率范围大,系统扩展性强。     

Distance measurement based on pixel variation of CCD images

This paper presents a distance measurement method based on pixel number variation of CCD images by referencing to two arbitrarily designated points in the image frames. By establishing a relationship between the displacement of the camera movement along the photographing direction and the difference in pixel count between reference points in the images, the distance from an object can be calculated via the proposed method. To integrate the measuring functions into digital cameras, a circuit design implementing the proposed measuring system in selecting reference points, measuring distance, and displaying measurement results on CCD panel of the digital camera is proposed in this paper. In comparison to pattern recognition or image analysis methods, the proposed measuring approach is simple and straightforward for practical implementation into digital cameras. To validate the performance of the proposed method, measurement results using the proposed method and ultrasonic rangefinders are also presented in this paper.     

数字图像技术在颗粒流测量中的应用

针对目前颗粒流速度场测量手段较单一的现状,系统介绍了基于数字图像技术的颗粒流速度场测量方法。通过对各种测量原理和使用条件的分析比较,指出了这些方法的特点和存在的主要问题,并结合颗粒流测量特点给出了这些测量方法在颗粒流速度场研究中的具体应用条件。此外,还讨论了数字图像技术在休止角测量方面的应用,以及这些测量方法在国内外的应用情况。这将对后续利用数字图像技术研究颗粒流提供指导。     

Dynamic range and background filtering in raster image correlation spectroscopy

Raster-scan image correlation spectroscopy (RICS) enables researchers to measure molecular translational diffusion constants and concentrations from standard confocal laser scanning microscope images and is suitable for measuring a wide range of mobility, especially fast-diffusing molecules. However, as RICS analysis is based on the spatial autocorrelation function of fluorescence images, it is sensitive to the presence of fluorescent structures within the image. In this study, we investigate methods to filter out immobile or slow moving background structures and their impact on RICS results. Both the conventional moving-average subtraction-based method and cross-correlation subtraction-based method are rationalized and quantified. Simulated data and experimental measurements in living cells stress the importance of optimizing the temporal resolution of background filtering for reliable RICS measurements. Finally, the capacity of RICS analysis to separate two species is studied.     

一种适用于特征稀少零件的图像精确拼接方法

针对特征稀少零件的图像精确拼接难题,提出了一种基于相位相关法和闭环运动控制的图像精确拼接方法,以充分发挥软硬件的综合优势。该方法以具有足够特征信息的零件为对象,获取成像系统分别沿X轴和Y轴运动时的零件等距序列图像并预处理,再利用相位相关法求解图像配准参数。在闭环运动控制系统的良好重复定位精度支持下,将上述图像配准参数视为系统配准参数,以进行特征稀少零件的图像拼接。典型零件的图像拼接实验表明,该拼接方法用于特征稀少零件的图像拼接具有无像素级拼接错位和拼接速度快等优点。     

Image analysis of insulation mineral fibres

We present two methods for measuring the diameter and length of man-made vitreous fibres based on the automated image analysis of scanning electron microscopy images. The fibres we want to measure are used in materials such as glass wool, which in turn are used for thermal and acoustic insulation. The measurement of the diameters and lengths of these fibres is used by the glass wool industry for quality control purposes. To obtain reliable quality estimators, the measurement of several hundred images is necessary.
These measurements are usually obtained manually by operators. Manual measurements, although reliable when performed by skilled operators, are slow due to the need for the operators to rest often to retain their ability to spot faint fibres on noisy backgrounds. Moreover, the task of measuring thousands of fibres every day, even with the help of semi-automated image analysis systems, is dull and repetitive. The need for an automated procedure which could replace manual measurements is quite real.
For each of the two methods that we propose to accomplish this task, we present the sample preparation, the microscope setting and the image analysis algorithms used for the segmentation of the fibres and for their measurement. We also show how a statistical analysis of the results can alleviate most measurement biases, and how we can estimate the true distribution of fibre lengths by diameter class by measuring only the lengths of the fibres visible in the field of view.     

一种全自动显微镜快速聚焦方法

自动聚焦技术是全自动控制显微镜系统的核心部分,主要解决的问题是如何提高聚焦的精度和速度,其中聚焦评价函数用来衡量图像是否聚焦。通过对几种聚焦评价函数的仿真实验对比分析,以及结合实际工程应用,提出一种直接截取图像的视频信号进行实时处理的聚焦方法,并对其中的关键技术分析、实验。实验表明:该方法提高了聚焦的精度和速度,并且它已成功应用于显微镜自动调焦系统中。     

反求激光条纹中心的提取方法研究

在多关节三维测量仪的研究中，为了能较好的排除环境光干扰，提高光条中心的提取精度，作者提出了一种结合梯度法改进的阈值法和重心法相结合的光条中心提取算法。并且在实验室制造的HRE—Ⅰ型三维激光扫描仪上进行实验。最后，通过实验的方法证明该方法具有好的鲁棒性，排除了环境噪音的影响，提高了图像的清晰度，精度达到亚像素级。     

采用图像光测法的油液污染的在线监测与预报

该文分析了图像处理法和光测法的优缺点及用于在线式测量的可行性,然后结合这2种方法提出了更加简便的图像光测法,并设计了基于图像光测法的油液污染度在线监测与预报系统,包括系统方案设计、传感器结构设计、主要电路接口设计、预测算法设计和上位机界面设计等。     

Integration of industrial photogrammetry and neuro-fuzzy system for measuring and modeling deformation of industrial product surfaces under external forces

Deformation of surfaces under external loadings greatly is function of physical laws. But according to the impossibility of identifying all effective factors and modeling their interactions parametrically, analytical methods do not provide good performance generally. So, it is necessary to apply practical methods by carrying out field tests and measuring deformations directly. To achieve this purpose it is required to integrate capabilities of an accurate measurement technique and a flexible modeling method. The capabilities such as: high accuracy and speed in measuring 3D coordinates of desired points, ability to perform measurement in a continuous space and no need to contact with the surface of objects at the time of measurement make close range photogrammetry a reliable tool for measuring geometric parameters of an object before and after deformation. The ability to measure geometric parameters of an object before and after deformation in one hand and following the deformation from physical laws on the other hand make neuro-fuzzy system the first choice for modeling the deformation of objects using outputs of close range photogrammetry.In this paper, a new method has been presented for measuring and modeling deformation of industrial product surfaces under external forces using close range photogrammetry (as an image-based measurement tool) and neuro-fuzzy network (as a behavior modeling tool).     

贝壳表面形貌测量技术研究

为研究开发仿贝壳表面微观形貌的船舶绿色防污技术,提出一种有效测量贝壳表面形貌的方法,即通过带有图像采集系统的光学显微镜观察贝壳表面形貌,初步确定测量贝壳表面形貌的采样条件,按照该采样条件对贝壳表面形貌进行多次测量,计算出多次测量结果的表面功率频谱和累计功率频谱,根据这两频谱图上的功率谱值的分布情况来验证贝壳表面合适采样条件方法的合理性。采用该方法分别测量日本镜蛤、青蛤、菲律宾蛤仔、魁蚶和华贵栉孔扇贝5种贝壳表面4个不同位置处的表面形貌,应用单因素方差分析法比较5种贝壳不同位置处的表面形貌特征。结果表明,采用该方法确定的用于测量贝壳表面形貌的采样条件是合适的;所选5种贝壳中的任一种在不同位置处的表面形貌特征无显著差异。     

Estimation of the standard deviation in three-dimensional microscopy by spatial statistics

Usually, the calibration process for three-dimensional microscopy involves the use of a reference flat surface. The random fluctuations of the topographic image for this reference surface are used for determining the uncertainty of the microscope. When the sample material or the measuring conditions of the microscope are modified (such as the objective used in a confocal microscope, or the tip in an atomic force microscope), the measuring conditions vary and thus a new calibration is required. In this work, a technique based on spatial statistics methods (more specifically, the variogram function) is proposed to determine accurately the standard deviation for three-dimensional microscopy that does not require a reference flat surface and therefore eliminates the need for a previous calibration process of this parameter.     

结合局部特征的无参考彩色图像质量评价

由于传统的无参考彩色图像质量评价方法与人眼感知结果的一致性较差,本文提出了一种全面利用待评价图像的色度、锐利度和对比度的无参考彩色图像质量客观评价方法。分析了彩色图像锐利度的局部特征,提出了一种新的彩色图像锐利度测量模型。基于对比度的局部特征和Buchsbaum曲线特征,建立了新的彩色图像对比度测量模型。最后,通过线性组合色度测量模型、锐利度测量模型和对比度测量模型,构建了无参考彩色图像质量评价函数。利用TID2013数据库中的3类退化图像(高斯模糊图像、对比度改变图像和噪声图像)验证了本文提出的锐利度测量模型、对比度测量模型和无参考彩色图像质量评价函数的性能。结果表明,本文提出的锐利度测量模型和对比度测量模型的性能均优于传统的锐利度和对比度计算模型。提出的无参考彩色图像质量评价函数的Spearman秩相关系数(SROCC)为0.904,Kendall秩相关系数(PROCC)为0.865,Pearson线性相关系数(PLCC)为0.922,亦均优于传统方法。     

Modified cuckoo search algorithm in microscopic image segmentation of hippocampus

Microscopic image analysis is one of the challenging tasks due to the presence of weak correlation and different segments of interest that may lead to ambiguity. It is also valuable in foremost meadows of technology and medicine. Identification and counting of cells play a vital role in features extraction to diagnose particular diseases precisely. Different segments should be identified accurately in order to identify and to count cells in a microscope image. Consequently, in the current work, a novel method for cell segmentation and identification has been proposed that incorporated marking cells. Thus, a novel method based on cuckoo search after pre‐processing step is employed. The method is developed and evaluated on light microscope images of rats’ hippocampus which used as a sample for the brain cells. The proposed method can be applied on the color images directly. The proposed approach incorporates the McCulloch's method for lévy flight production in cuckoo search (CS) algorithm. Several objective functions, namely Otsu's method, Kapur entropy and Tsallis entropy are used for segmentation. In the cuckoo search process, the Otsu's between class variance, Kapur's entropy and Tsallis entropy are employed as the objective functions to be optimized. Experimental results are validated by different metrics, namely the peak signal to noise ratio (PSNR), mean square error, feature similarity index and CPU running time for all the test cases. The experimental results established that the Kapur's entropy segmentation method based on the modified CS required the least computational time compared to Otsu's between‐class variance segmentation method and the Tsallis entropy segmentation method. Nevertheless, Tsallis entropy method with optimized multi‐threshold levels achieved superior performance compared to the other two segmentation methods in terms of the PSNR.     

KDP\DKDP倍频晶体吸收系数的斜入射测量

考虑惯性约束聚变系统中的磷酸二氢钾/磷酸二氘钾(KDP\DKDP)的吸收系数直接影响系统的转换效率及最终输出能量,本文研究了KDP\DKDP倍频晶体吸收系数的测量方法。提出了新的基于朗伯定律的倍频晶体吸收系数斜入射测量法。建立了斜入射状态下入射光偏振态与晶体o光和e光的关系模型,推导了小角度入射下晶体e光折射率的迭代计算方法。采用该方法计算了晶体的e光折射率,通过测量得到的数据间接计算出了KDP\DKDP倍频晶体吸收系数。详细分析了该方法在测量过程中的各项误差来源,得出该方法测量误差优于0.000 2cm~(-1)。最后,对一块40mm×40mm×60mm的开关晶体元件进行测试并与分光光度法比对以验证提出方法的可行性,结果显示两种测量方法的偏差小于0.000 2cm~(-1),表明该方法可用于惯性约束聚变系统中倍频晶体吸收系数的测量。     

Enhanced visualization of histological samples with an adjustable RGB contrast system with application for tissue used in photodynamic therapy

The analysis of histological sections has long been a valuable tool in the pathological studies. The interpretation of tissue conditions, however, relies directly on visual evaluation of tissue slides, which may be difficult to interpret because of poor contrast or poor color differentiation. The Chromatic Contrast Visualization System (CCV) combines an optical microscope with electronically controlled light-emitting diodes (LEDs) in order to generate adjustable intensities of RGB channels for sample illumination. While most image enhancement techniques rely on software post-processing of an image acquired under standard illumination conditions, CCV produces real-time variations in the color composition of the light source itself. The possibility of covering the entire RGB chromatic range, combined with the optical properties of the different tissues, allows for a substantial enhancement in image details. Traditional image acquisition methods do not exploit these visual enhancements which results in poorer visual distinction among tissue structures. Photodynamic therapy (PDT) procedures are of increasing interest in the treatment of several forms of cancer. This study uses histological slides of rat liver samples that were induced to necrosis after being exposed to PDT. Results show that visualization of tissue structures could be improved by changing colors and intensities of the microscope light source. PDT-necrosed tissue samples are better differentiated when illuminated with different color wavelengths, leading to an improved differentiation of cells in the necrosis area. Due to the potential benefits it can bring to interpretation and diagnosis, further research in this field could make CCV an attractive technique for medical applications.     

几种波片位相延迟测量方法的比较

建立了用于波片位相延迟测量的高精度多功能测试系统,实现了在同一测试系统上应用不同的测试方法,使测试具有可比性。对光谱扫描法、Soleil补偿器法及两种光强法进行了比较测量,并结合测试结果对各种方法进行了系统的误差分析。分析结果表明,对本测试系统而言,光谱扫描法适于测量λ/2波片,测量精度主要由单色仪的精度所决定,其误差＜0.032%;Soleil补偿器法测量精度主要由Soleil补偿器精度决定,其误差＜0.18%;光强法误差与待测波片的延迟量有关,且测试光路与偏振器的缺陷对测量精度影响较大。光谱扫描法与Soleil补偿器法测量λ/2波片的结果在误差范围内相符,光强法测量结果产生较大差异的原因来自光路、偏振器及方法本身的缺陷。实验结果为不同条件下选择最佳测量方法提供了参考依据。     

Correction of image drift and distortion in a scanning electron microscopy

Continuous research on small‐scale mechanical structures and systems has attracted strong demand for ultrafine deformation and strain measurements. Conventional optical microscope cannot meet such requirements owing to its lower spatial resolution. Therefore, high‐resolution scanning electron microscope has become the preferred system for high spatial resolution imaging and measurements. However, scanning electron microscope usually is contaminated by distortion and drift aberrations which cause serious errors to precise imaging and measurements of tiny structures. This paper develops a new method to correct drift and distortion aberrations of scanning electron microscope images, and evaluates the effect of correction by comparing corrected images with scanning electron microscope image of a standard sample. The drift correction is based on the interpolation scheme, where a series of images are captured at one location of the sample and perform image correlation between the first image and the consequent images to interpolate the drift–time relationship of scanning electron microscope images. The distortion correction employs the axial symmetry model of charged particle imaging theory to two images sharing with the same location of one object under different imaging fields of view. The difference apart from rigid displacement between the mentioned two images will give distortion parameters. Three‐order precision is considered in the model and experiment shows that one pixel maximum correction is obtained for the employed high‐resolution electron microscopic system.     

Analysis,filtering, and decomposition of electron microscope images based on orthogonal transformations

Methods for estimating the integral characteristics of electron microscope image periodograms, based on Hartley transform, Q-transform, and cosine transform, are proposed. It is shown that the cosine transform is more appropriate for filtering and improvement of psychophysical image perception on its basis. Various approaches to implementing matched filtering via cosine transform are considered. A procedure of electron microscope image decomposition with the use of various orthogonal transforms and filters based on Fourier patterns of Gauss and Morle wavelets is proposed and studied. It is shown that electron microscope image structure analysis using scalograms of orthogonal image transforms is promising.