基于改进爬上算法的数字显微镜自动对焦方法

自动对焦技术是计算机视觉、成像系统和各种精密仪器应用中的关键技术之一。随着科学技术的飞速发展,越来越多的人更加关心如何实现数字显微镜快速而精确的自动对焦问题。近年来人们对自动对焦技术的研究也多集中在数字图像处理的方法上。但是,在一般情况下,成像目标具有复杂性与不确定性的特点,因此,在数字成像系统中,现有的自动对焦技术仍然存在诸多不足,比如,对焦评价函数以及对焦的实时性与精确性等方面。通过对实验数据的分析,提出了一种改进的爬山算法通过在特定阶段采用特定对焦评价函数的方法,最终实现了自动对焦的目的,在保证调焦精度的情况下有效提高了自动对焦的速度。     

手机摄像模组测试设备调校效率的优化

随着手机拍照要求和性能的提升,相位检测自动对焦(PDAF)类模组广受关注。由于手动方式测试此类模组测试效率低、测量精度低、工人劳动强度大等不足,结合实际生产情况,综合机械设计、机械理论、工程材料等相关知识,通过理论计算与实际模拟相结合的方式,设计并制造了1台三工位自动对焦设备,其实际生产效率能够达到210片/h。为了更好地提高工作效率,进一步将三工位自动对焦测试设备改造成六工位自动对焦设备,改造后生产效率能够达到360片/h,测试效率提升了70%左右。     

光显微成像系统自动对焦技术的研究

自动对焦技术是精密光学仪器中的关键技术。随着科学技术的发展和应用要求的提高,对具有精度高、速度快和稳定性好的自动对焦技术的需求越来越迫切。针对以上问题,基于显微镜系统简要介绍自动对焦技术,并提出一种快速离焦深度计算方法,不但减少了估计离焦量的计算量而且不需改变光学系统内部参数,尤其适合显微对焦系统。同时还提出结合型的对焦新方法,实现高效率、高精度的对焦。     

单唇密封圈检测装置自动对焦策略研究

为了解决单唇密封圈内径尺寸检测装置中镜头精确对焦的问题,设计了一种基于图像处理的自动对焦策略。将相机固定在直线滑台上,计算机控制电机转动,带动滑台上的相机移动并采集图像,利用改进的清晰度评价函数对采集的图像进行评价,然后电机驱动模块带动相机移动到图像清晰度最佳的位置,完成系统的自动对焦功能。将一种引入阈值的"四邻域"能量梯度算法作为改进的清晰度评价函数,通过与频域函数、灰度方差函数、Tenengrad梯度函数及熵函数等多种图像清晰度评价函数对比,验证了该函数的优越性。试验结果表明:使用改进算法设计的自动对焦策略能实现快速、准确的自动对焦。自动对焦策略解决了检测装置中镜头对焦的问题,并可以应用于多规格单唇密封圈内径尺寸检测。     

投影微分法实现多光谱成像仪的自动对焦控制

基于投影微分算法提出了一种应用于多光谱成像仪的自动对焦方法,该方法结合图像处理单元和多个波段的探测器调焦辅助机构来同时实现多个波段的独立自动对焦.首先,根据观测需要对自动对焦窗口进行手动选取,或结合投影微分与目标边缘的对应关系进行对焦窗口的自动选择;然后,将参与自动对焦计算的图像的对焦窗口内的数据做x与y方向投影,对这两个方向投影数组的微分1范数均值求均方根,并将其作为该帧图像的清晰度评价值;最后,结合经典的爬山搜索算法,完成系统的自动对焦过程.实验结果显示,同等条件下投影微分算法与经典的Brenner、能量梯度及Roberts梯度和算法具有同样好的评价效果,能够准确地实现系统的自动对焦,而其算法时间分别仅为这3种算法的0.67、0.33和0.33倍.这些结果表明,投影微分算法具有良好的单峰性与无偏性、较高的灵敏度及很好的实时性,能够满足系统的高精度自动对焦要求.     

一种近距离物体优先的对焦窗口选择策略

随着数码相机普遍进入千万级有效像素的行列,大多数相机都采用了多个对焦窗口的自动对焦技术。为实现对焦窗口的快速选择和自动对焦,文中采用统计分析的方法,研究了近距离物体优先的对焦窗口自动选择的可行性,就选择适宜的对焦评价函数提出建议;通过MatLab仿真实验给出了评价函数的大小阈值,提出了近距离物体优先的对焦窗口自动选择和自动对焦策略,给出了对焦搜索基本流程。这种对焦窗口选择,实时性好,适用性强,可作为数码相机的一种对焦窗口自动选择策略。     

一种变物距的自动对焦方法

针对像距无法改变的特定环境,提出了一种变物距的自动对焦方法。首先通过设置标志矩形,采用SUSAN算法中的角点获取算法,取得对焦窗口;其次建立对焦窗口转换函数,使不同物距下的对焦窗口包括相同的成像信息;最后使用能量梯度对焦评价函数,取得最佳对焦位置。实验表明,该系统适用于像距无法改变的环境,并且具有良好的自动对焦精度、速度以及鲁棒性。     

一种新型多段式自动对焦模块

自动对焦广泛应用于数码相机、手机照相模块。本文论述的一种新型的多段式自动对焦镜头模块，该新型采用步进电机作为动力源，步进电机与镜头之间采用蜗轮、蜗杆及丝杠、螺母传动方式。本结构可得到较大传动比，使镜头移动获得较大的动力，实现较精确的镜头位移，同时有效缩小空间。     

对数功率谱离焦深度法在多光谱成像仪的应用

结合多光谱成像仪的成像特点,提出了一种基于对数功率谱的离焦深度自动对焦方法.以CCD相机为图像传感器,通过主控计算机进行调焦控制与图像处理来实现多光谱成像仪的快速自动对焦.首先,将相机探测器依次处于3个等距位置各采集一幅图像,结合三点判位法判断第二幅图片与准确对焦位置的位置关系.然后,以第二幅图片为参考图片,通过对其对数功率谱的相关计算得到准确的对焦位置.最后,将探测器移动到该计算位置,完成自动对焦过程.实验结果表明,系统对焦位置标准差为±0.159 9 mm,最大偏差值控制在0.4 mm以内,能够较好地满足系统的实时自动对焦要求.该调焦算法只需3幅图片即可完成自动对焦过程,具有调焦迅速,准确度高等特点.     

基于Internet的嵌入式数字图像自动对焦系统

提出了一种利用网络技术实现嵌入式数字图像自动对焦系统远程监控的方法,建立了基于DM642的数字显微镜自动调焦系统,设计了系统的网络传输应用程序。最后通过实验证明了该方法的可行性。     

Omnifocus video camera

The omnifocus video camera takes videos, in which objects at different distances are all in focus in a single video display. The omnifocus video camera consists of an array of color video cameras combined with a unique distance mapping camera called the Divcam. The color video cameras are all aimed at the same scene, but each is focused at a different distance. The Divcam provides real-time distance information for every pixel in the scene. A pixel selection utility uses the distance information to select individual pixels from the multiple video outputs focused at different distances, in order to generate the final single video display that is everywhere in focus. This paper presents principle of operation, design consideration, detailed construction, and over all performance of the omnifocus video camera. The major emphasis of the paper is the proof of concept, but the prototype has been developed enough to demonstrate the superiority of this video camera over a conventional video camera. The resolution of the prototype is high, capturing even fine details such as fingerprints in the image. Just as the movie camera was a significant advance over the still camera, the omnifocus video camera represents a significant advance over all-focus cameras for still images.     

利用胶片反射光的直接测光系统及其分析计算

普及型照相机测光系统中，测光在时间或空间上与实际曝光不一致，从而影响曝光量控制精度。利用胶片平面反射光的直接测光系统是一种与实际曝光量非常接近的测光系统，无时间差、无空间差，测光精度很高。本文较详细地分析了一种特殊用途照相机使用的高精度直接测光系统，对系统光能量计算作了详细分析，并给出了结论。     

长焦距斜视实时航空相机离焦补偿

基于一种长焦距斜视实时航空相机的研制,探讨了导致相机离焦的原因,指出环境(大气压力、温度)变化和照相斜距的变化是导致相机离焦的主要原因,分别从温度、大气压力、照相斜距这三个方面的变化对相机离焦的影响进行讨论,给出了计算相机离焦量的简易数学方程。通过对相机斜距离焦的分析,提出了一种新的离焦补偿方法,研制出一种双层导轨、双层凸轮的自动调焦补偿机构,使相机在照相过程中保持像面稳定,并对斜距调焦原理进行了实际检验。     

Multiplexed time-lapse photomicrography of cultured cells

A system of cinemicrography has been developed in which a single microscope and 16 mm camera are multiplexed to produce a time-lapse photographic record of many fields simultaneously. The field coordinates and focus are selected via a control console and entered into the memory of a dedicated microcomputer; they are then automatically recalled in sequence, thus permitting the photographing of additional fields in the interval between exposures of any given field. Sequential exposures of each field are isolated in separate sections of the film by means of a specially designed random-access camera that is also controlled by the microcomputer. The need to unscramble frames is thereby avoided, and the developed film can be directly analysed.     

照相机聚焦精度检查仪的设计

照相机聚焦精度检查仪是检校照相机物距刻度精度的专用仪器。介绍了照相机聚焦精度检查仪的结构及工作原理 ,并作了精度分析。该仪器利用分光镜的工作原理 ,具有精度高、体积小、操作简便等优点     

画

长焦距、大画幅、高分辨力胶片摄影相机要求在给定的摄影周期内快速、精密地将胶片展平在片台上.为了在设计中准确、高效地确定胶片负压展平系统的片台结构参数、真空泵参数及电磁阀参数等,本文给出了一种用数值计算对胶片负压展平过程进行计算机模拟的方法.经实践证明本方法是行之有效的.     

Multi-camera interface with novel copositioning

This article reports a multi-camera system to determine the position of an object. By using novel copositioning and cameras in a wide range of orientations and viewing angles, the system solved the problem of dead zones and camera switching errors. When an object was close to a charge-coupled device camera, the system switched to that camera to become the focus by the algorithm. When an object left the optimum range of one camera, the system selected the next suitable camera to be the main detector. The position of the target and the grey level thresholds were continuously recorded and the changes were calculated. This interface system had the advantages of high positioning accuracy, fast response time, reduced noise in the light field, and no dead zones.     

Development of a compact tomography camera system using a multianode photomultiplier tube for compact torus experiments

A compact tomography camera system consisting of a photomultiplier tube, a multislit optical system, and a band-pass interference filter has been developed. The viewing area and spatial resolution can be configured by the arrangement of the slit system. The camera system has been specially designed for self-organized compact torus experiments having strong magnetohydrodynamics events with a submicrosecond time-scale. The developed system has been tested on a field-reversed configuration formed by the field-reversed theta-pinch. Performance evaluation of the system has been performed by comparison to the former optical system.     

AutoCAD系统中运动副仿真系统的构造

根据运动副的特点，运用AutoCAD计算机辅助设计系统，以提高设计工作效率和正确性为目的，讨论了运动副仿真系统的构造及其具体应用。     

An automatic optical inspection system for inspection of CMOS compact camera module assembly

This paper presents the development of an automatic inspection system to check lens focus status and white balance level and to inspect defects including black and white defect, dim defect, color defect, and line defects in manufacturing process of compact camera module. To check the imaging status and inspect the defects of compact camera module, a unique image capturing system is developed to get image data from CMOS sensor at high speed. It has a complex programmable logic device, and the camera link and the frame grabber is used to transfer and store images to PC. Several kinds of unique image charts are designed to inspect the various types of defects in compact camera module, and they are implemented and displayed on the LCD monitor directly to reduce handling and exchanging time of inspection charts during test procedures. Various image processing algorithms are developed to analyze the captured image from each test chart and to find and verify the defects of camera modules. The experimental results show that the proposed system is able to reliably inspect various types of defects with high precision and high speed in real manufacturing condition.