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针对现有球面光学元件表面疵病检测技术研究较少的情况,根据疵病对光的散射特性,提出了一种基于机器视觉技术检测球面光学元件表面疵病的方法。实验分析了光照角度、光强大小和球面光学元件曲率半径对疵病散射光成像质量的影响。并对口径为Φ14mm,曲率半径为13mm的球面光学元件表面进行了检测,实验表明,该技术对元件样品上10μm以下的表面疵病可进行有效的检测。 相似文献
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精密表面缺陷的数字化检测系统研究 总被引:3,自引:0,他引:3
精密表面疵病的自动检测长期以来一直是期待解决的问题。依据显微散射光成像系统对元件表面上的划痕、麻点、气泡等疵病形成暗背景下的亮疵病图像,提出了一个完整的数字化标准的精密表面疵病检测评估体系。首先利用比值匹配原理对xy两方向平移得到的子孔径扫描图像进行拼接。引入数学形态学实现疵病识别。运用膨胀、腐蚀、细化等算法,对二值化图像进行噪声消除,图像分割和特征提取。项目的研究成果已能分辨微米量级的疵病,为建立国内外疵病的数字化标准评价系统提供有力的理论及实验依据。 相似文献
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光电内窥参数检测装置 总被引:4,自引:1,他引:3
报导一种新的光电内窥参数测量装置。将一半导体激光器发出的光束经柱面镜汇聚成一细线,通过特殊设计的折反棱镜将其沿轴线方向投影到管孔内壁,得到管孔内壁的光截轮廓,该轮廓经物镜成像到CCD光敏面,通过图像卡采集到计算机。在计算机图像测量及辅助提示下,完成参数测量。此外,该装置还可在测量显微镜横向移动导轨及读数手轮的配合下测量内孔中径。实验结果表明轴向测量的重复精度为±17μm;中径测量的重复精度为±12μm.它在工业制造领域内具有广阔的应用前景。 相似文献
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针对树脂镜片表面疵病自动化检测的需求,开展了基于机器视觉的树脂镜片表面疵病边缘检测研究.设计一种改进的快速Hough圆检测方法获取镜片图像的感兴趣区域,采用混合滤波消除脉冲噪声和高斯噪声,提出一种基于局部窗口阈值的改进Canny边缘检测算法,选取局部最佳分割阈值,对窗口内的疵病实现精确分割.实验结果表明,该边缘检测算法能够较好地检测疵病边缘细节. 相似文献
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针对医疗器械要求高精度检测的特点,提出了采用图像拼接对器械进行检测的方法,通过Harris算子精确提取图像中的特征点进行图像拼接,不但极大提高了拼接精度以及精密医疗器械的检测精度,而且增加图像分辨力与成像范围。拼接精度是检测精度的保证,基于Harris算子的拼接图像可实现微米级高精度检测。通过该方法进行图像拼接并测量其精度,测试精度与单幅图像相比明显提高,结果完全符合器械检测要求。基于拼接的精密仪器测量是一种提高测量精度的新方法,这方面的研究必将推动机器视觉技术的进一步发展。 相似文献
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针对航空发动机中薄壁细长轴类零件的壁厚需要精密高效测量的问题,提出了一种双测头快速高精度测量方法。该方法以大长径比碳纤维测杆支撑小型非接触光学测头进行细长轴内壁测量,以龙门式框架安装接触式测头同时进行细长轴外壁测量,并采用高精度气浮平台作为工作台带动零件移动,从而实现对细长轴类零件的壁厚进行测量。采用该方法研制了测量设备,并详细介绍了机械、电控和软件设计。通过实验和第三方检测,该测量设备可对长度1 500 mm、内孔直径14 mm的细长轴进行壁厚测量,验证了本方法的有效性。 相似文献
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E. W. Hansen R. D. Allen J. W. Strohbehn M. A. Chaffee D. L. Farrington W. F. Murray T. A. Pillsbury M. F. Riley 《Journal of microscopy》1985,140(3):371-381
We describe the concept and first implementation of an innovative new instrument for quantitative light microscopy. Currently, it provides selective imaging of optical path differences due to birefringence; with further development, it is also possible to selectively image several optical properties, including refractive path differences, optical rotation, and linear and circular dichroism, all with diffraction-limited resolution. An image consists of a 512×512 element array, with each pixel displaying one of 256 grey levels, linearly proportional to the specific optical property being observed. Additionally, conventional brightfield and polarized light microscopy are available, with the accompanying advantages of laser scanning and digital image processing. The microscope consists of three subsystems, representing three distinct technologies. The laser scanning subsystem moves a focused, microspot across the specimen; the output of a photodetector is an electric signal corresponding to a scanned image. The image display subsystem digitizes this signal and displays it as an image on a video monitor. When used in conjunction with a phase modulation feedback loop, the image formed is of the specimen's birefringent retardation or other selected optical property. The digitized images are also available for computer enhancement. 相似文献
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We have developed a video signal processor for improving the operability and function of scanning near-field optical microscopy (SNOM). The video signal processor applies a CCD imaging device as a variable area photo-sensor in the SNOM unit instead of conventional photo-detectors. The signal processor converts the intensity of a selected area in video frames to a numerical value with a rate of 30 Hz. Consequently, the CCD imaging device can be used as a photo-detector of variable areas and positions for detecting a small area of a optical probe position. The need for a precise optical axis alignment is relaxed due to the large sensing area of the CCD device. Using the video signal processor, near-field optical and topographic images have been obtained by SNOM/AFM system simultaneously. By adding a spectrometer between the SNOM unit and the CCD device, the spectrum signal of selected wavelength ranges has been monitored by the video signal processor to provide an optical image. 相似文献
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介绍了一种新的 CCD技术。通过研究图像像素和 CCD像敏元之间的对应关系 ,从而可以找到图像上的点在探测器面阵上相应的精确位置。它主要涉及到视频信号同步分离技术、视频信号合成技术、脉冲宽度测量技术、计算机接口技术以及计算机程序设计技术等。首先我们要对视频信号进行分析 ,提取出行同步和场同步信号 ,在此基础上产生测量标志线脉冲 ,通过视频合成输出带有标志线的复合视频信号 ,同时我们要精确测定标志脉冲的位置 ,以数据形式提供给计算机 ,通过计算机对图像和所采集的数据的分析处理 ,最后得到表征图像像素和 CCD像敏元对应关系的水平和垂直常数 Const H、Const V。 相似文献
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针对角膜图像采集系统开发过程中的面阵CCD图像传感器驱动进行了设计。选用ICX424AL面阵CCD作为图像采集系统的图像传感器,分析了ICX424AL的驱动时序要求,介绍了高性能模拟前端处理芯片AD9949A内部主要电路模块的工作原理及相关电路的寄存器控制方法,实现了基于CPLD与AD9949A的ICX424AL驱动设计。最终测试结果显示,CCD可产生正确的模拟信号输出,将数字视频信号采集到计算机后,能够得到良好的图像采集效果。 相似文献
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《Flow Measurement and Instrumentation》2000,11(2):133-141
A particle image velocimetry (PIV) instrument using a video frame grabbing system and two unsynchronised CCD video arrays was constructed. In the optical device, the two CCD are positioned at two perpendicular axes, with an image splitter located at their intersection and a single imaging lens in front of it. An optical characterisation of each CCD array and the imaging lens is needed to ensure that the field of view is similar for each vision system. Firstly, the experimental method of Cornu was used to deduce the basic optical parameters of the imaging lens. A simple video model was then performed to extract the unknown optical parameters of the device such as the angular field of view, the efficient dimensions of each CCD array and the transfer function from the CCD to the TV screen. An identification method based on global magnification measurements allowed the resolution of the micrometric stages needed for the spatial calibration step of the final instrument, to be deduced. Experimental tests have shown that the aberration in image formation was minimum with this configuration. 相似文献
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基于信息理论的采样成像系统评价方法 总被引:4,自引:4,他引:4
论述了基于信息理论的采样成像系统评价的理论基础,讨论了光学系统信息量、图像信息量的处理方法。提出了采样成像系统中基于信息理论的光电一体化系统设计方法。通过实现光学成像系统与CCD探测系统的匹配设计,减小了欠采样噪声,改善了成像质量。 相似文献