共查询到19条相似文献,搜索用时 140 毫秒
1.
一种用于数字成像的自动对焦系统 总被引:10,自引:0,他引:10
提出一种用于数字成像的自动对焦系统,它以CMOS为图像传感器,用DSP进行数据处理并控制驱动电路调整镜头的位置,达到准确自动对焦的目的。系统采用对焦深度法实现自动对焦,通过改变镜头的位置获得一系列模糊程度不等的图像,计算每幅图像的清晰度评价值构成对焦评价曲线;采用梯度函数作为评价标准来评价图像的清晰度;采用窗口选择技术控制对焦感兴趣范围,减少了数据处理量;对实验样机的测试表明,系统有较好的自动对焦性能,并解决了百叶窗问题,对透过玻璃窗户的目标仍然能正确对焦。 相似文献
2.
尼柯尔 AF-S F2 .8/4 0 0 mm D IF-ED镜头的主要特点有 :1、镜头内装备了尼康独特的超声波马达驱动系统 ,可以提供超快速的自动对焦。虽然是超快速的自动对焦 ,仍能达到摄影者意想不到的精确度 ,并能保持静音运作的特性。2、该镜头与尼康 F80型、F1 0 0型、F5型或 F90 X型配合使用 ,可获得最佳的自动对焦效果。与其他尼康单镜头反光相机配合使用 ,可用手动对焦方式进行操作。3、在这种镜头上同时运用了两种特别的新材料——树脂材料及碳化纤维材料 ,因此该镜头比尼柯尔 AF-I F2 .8/4 0 0 mm D IF-ED镜头轻了1 5 0 0克。4、尼康依… 相似文献
3.
4.
一、主要规格性能类型:35mm自动对焦单反照相机对焦:自动对焦或手控对焦;胶片平面自动对焦系统有单点和连续的相位检测AF方式,AF感应范围EV-2~21(ISO100)。镜头:蔡司T系列镜头,采用康太克斯MM转换器;康太克斯ML镜头具有光圈优先AE或手动曝光功能。曝光:光圈优先AE,快门优先AE,程序AE,手动曝光,在五棱镜后面的硅光电二极管(SPD)作中央重点测光(E*0一2且)或5__的点测光(E*3一ZI),曝光补偿上ZEV,1/3级分档;自动括弧曝光上IEV,可选择上0.5或上1曝光偏差值。取景器:平视五棱取景器有内藏屈光度调… 相似文献
5.
6.
PentaxZ系列及MZ系列各有何特点符号D、QD为何意kJ不同焦距如何确定光圈r金属卡口镜头与塑料机身应是否相配@间:从贵刊得知单反自动对焦机中Nikon与Pentax可与其原厂手动镜头通用,而尼康因其质优价高,不敢轻取,则求其次Pentax。请问PentaxZ系列及MZ系列相机各有何特点或优点?其符号D\QD为何意?再其相配自动对焦镜头是否均有FA标示。(成都刘茂芬)F口l:Pentaxz系列相机是80年代末推出的自动对焦单反相机,Z—IP是该厂的自动对焦顶级相机,Z—20、Z—50、Z—70相机是该系列中的业余型相机。MZ系列则是90年代推出的自动… 相似文献
7.
尼柯尔AF-SF2.8/400mmDIF-ED远摄镜头据尼康摄影器材中国代理亮驰发展有限公司提供的信息,一支全新设计的大口径远摄定焦镜头──尼柯尔AF-SF2.8/400毫米DIF-ED镜头已经推出。尼柯尔AF-SF2.8/400毫米DIF-ED镜头的主要特点有:@镜头内装备了尼康独特的超声波马达驱动系统,可以提供超快速的自动对焦。虽然是超快速的自动对焦,仍能达到摄影者意想不到的精确度,并能保持静音运作的特性。t该镜头与尼康FS型、F90X型或F70型相机配合使用,可获得最佳的自动对焦效果。与其他尼康单镜头反光相机配合使用,可用手动对… 相似文献
8.
9.
美能达AF28─135mmf/4~4.5镜头是日本美能达公司第一代自动对焦镜头,于1985年推出。同美能达公司80年代末和90年代以来生产的镜头相比,该镜头有其独特之处,现简介如下。镜头基本规格:长109mm,最大直径75mm,滤镜直径72mm,结构是13组16片,最近对焦距离1.sin,微距放大率1:4,最小光圈F22~F27,重量7709。镜头采用后对焦结构,有资料称是世界上第一只后对焦结构镜头,其特点是对焦机构和手动对焦环设在镜头尾部,对焦时前组镜片不动,方便使用偏振镜等滤第。据笔者所知,美能达后来生产的自动对焦镜头,除G系列外(中国市场基… 相似文献
10.
11.
12.
文中介绍了一套风量罩自动校准系统,自动转换差压-风量值,运用摄像头来捕捉识别被检风量罩的读数,通过USB通信,实现风量罩示值的自动校准。 相似文献
13.
14.
Sheng‐Fuu Lin You‐Tasi Lin Chien‐Kun Su 《International journal of imaging systems and technology》2002,12(6):235-238
A simple and effective automatic focusing algorithm is proposed in this article. The principle of the proposed automatic focusing algorithm is based on that, for the radial test pattern, a best‐focused image should have the smallest blurred region in the middle of the acquired image, and hence, should have the smallest equivalent radius. The circular Hough transform has became a common method in numerous image‐processing applications for circle detection. Various modifications to the basic circular Hough transform have been suggested, such as: the inclusion of edge orientation, simultaneous consideration of a range of circle radii, the use of a complex accumulator array with the phase proportional to the log of the radius, or for filter operations. The purpose of this work is to show that a radius of a circular region extracted by a normalized circular Hough transform is a possible solution for determining the sharpness of images. To acquire high quality images with a given CCD camera, it is crucial that the camera be located exactly at the back length of the lens, i.e., the focus position of the lens. In the best conditions, the contours of the acquired images are of the sharpest, with none of the blurring effects associated with unfocused images. Acquiring such high quality images by these means is the main goal of the automatic focusing algorithm proposed in this article. © 2003 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 12, 235–238, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.10029 相似文献
15.
16.
17.
We demonstrate a compact, automated, long working distance optical tweezer system using a novel mechanism for controlling the position of the optical trap. Our system uses a single focusing lens with a working distance of 4.5?mm and the trapping beam is steered by moving the lens with a miniature coil-magnet assembly. The sample is imaged through a 100×?microscope objective and a CCD camera captures the magnified image. A custom image processing software detects the position of the laser beam and identifies the sample objects. This information is used to generate appropriate electrical signals to drive the coils which move the focusing lens along the desired path. The system is fairly simple and power efficient due to minimal usage of optical elements in the laser path; hence our setup is simple, low-cost and requires low optical power. Computer-generated arbitrary trapping paths and time-shared trapping patterns are successfully demonstrated. Efficient trapping of micron size spheres with laser powers as low as 1.5?mW is observed. 相似文献
18.
《IEEE transactions on instrumentation and measurement》1977,26(2):88-91
A video detection and tracking system was devised to track and record the position versus time of tracer particles moving through a transparent medium. The system was applied to studying the flow-related transport phenomena at all points within packed-bed reactors since the previously proposed mathematical models for describing them have not been proven adequate thoughout the entire packed-bed. A modified TV camera was used to obtain a video presentation of the motion of a highly reflective particle in an otherwise transparent bed. A microcomputer was then used to process the video signal, using the vertical and horizontal sync pulses as timing signals. Output of the system was a punched paper tape with position versus time data for later analysis in a large computer. 相似文献