Design of object surveillance system based on enhanced fish-eye lens

A new method is proposed for the object surveillance system based on the enhanced fish-eye lens and the high speed digital signal processor （DSP）. The improved fish-eye lens images an ellipse picture on the charge-coupled device （CCD） surface, which increases both the utilization rate of the 4：3 rectangular CCD and the imaging resolution, and remains the view angle of 183° The algorithm of auto-adapted renewal background subtraction （ARBS） is also explored to extract the object from the monitoring image. The experimental result shows that the ARBS algorithm has high anti-jamming ability and high resolution, leading to excellent object detecting ability from the enhanced elliptical fish-eye image under varies environments. This system has potential applications in different security monitoring fields due to its wide monitoring space, simple structure, working stability, and reliability.     

基于变焦镜头的机载相机监控系统设计及试验

机载遥感监控系统因其灵活机动、可重复使用且风险小的优势,为专题化、智能化获取国土、资源、环境等遥感信息提供了有力的支持。为了满足大视场范围监控和小视场特定目标观测的需求,设计并实现了基于变焦镜头的机载相机监控系统,能够实现12倍的连续变焦,包括电动变焦控制、高速成像存储以及不同分辨率图像拼接等。在经过地面可靠性验证和总体功能完善后,完成了航空搭载飞行试验,获取了相对航高为3000m、约7GB的连续变焦的不同地面分辨率图像,利用四分法改进的SURF(Speeded-up robust featrues)拼接算法对不同地面分辨率图像进行连续拼接,能够得到大场景范围的良好拼接图像,并保持高分辨率图像的细节部分。     

用于监控系统的鱼眼镜头光学设计

为了满足监控系统中单镜头可实现全景监控的需求,运用仿生学原理,在原有鱼眼镜头的基础上结合监控系统的需求,运用ZEMAX软件设计了一款视场为180°,相对孔径为1/1.6的鱼眼镜头.该镜头由9片透镜组成,总长度为68.5mm,采用1/3英寸CCD作为图像接收器件.在120lp/mm时,其MTF曲线在轴上大于0.4,在80...     

A distortion correction algorithm for fish-eye panoramic image of master-slave visual surveillance system

A master-slave visual surveillance system is composed of one fish-eye panoramic camera and one dynamic pan-tilt-zoom (PTZ) dome camera. In order to make PTZ dome camera zoom into all targets of interest in panoramic image, the fish-eye panoramic camera is fixed inclining towards the gravity direction, which may cause more obvious distortion. This paper proposed a novel method for the distortion correction of captured panoramic image based on the midpoint circle algorithm (MCA). The method uses incremental calculation of decision parameters to determine the pixel positions along a circle circumference, and both of the vertical and horizontal are rectilinearised. Experimental results show that our correction method based on MCA is efficient and effective. In particular, due to its low computational cost, our method can be applied on embedded camera platform without any extra hardware resources.     

基于鱼眼镜头的目标监控与测量系统分析

为了实现超大范围的目标监控与测量,设计和分析了一种基于鱼眼镜头的超广角监测系统。以鱼眼镜头和CCD作为图像采集系统,以DSP作为控制和处理中心,采用自适应动态更新背景差方法进行目标识别,利用图像处理方法进行目标方位角测量,对前方半球空间中可能出现的目标进行监测。实验结果表明,基于鱼眼镜头的监控系统具有超大的监控视角,在各种环境下都具有较高的监控能力;基于动态更新背景的背景差目标识别方法具有较强的抗干扰性,能准确地识别出各种可能出现的目标,并能对其进行方位角测量。相对于传统的监控系统来说,具有监控范围大,结构简单,工作稳定可靠,在各种安全监控领域有着广泛的应用。     

An acoustic Maxwell's fish-eye lens based on gradient-index metamaterials

We have proposed a two-dimensional acoustic Maxwell's fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be gradually varied, which is key role to design the acoustic fish-eye lens. As predicted by ray trajectories on a virtual sphere, the proposed lens has the capability to focus the acoustic wave irradiated from a point source at the surface of the lens on the diametrically opposite side of the lens. The broadband and low loss performance is further demonstrated for the lens. The proposed acoustic fish-eye lens is expected to have the potential applications in directional acoustic coupler or coherent ultrasonic imaging.     

利用线阵CCD自动测量航空相机镜头的焦距

提出了一种以线阵CCD固态传感器取代读数显微镜的航空相机镜头焦距测量系统。论述了系统的工作原理、软件和硬件的设计及系统的测量误差。结果表明 ,利用线阵固态图像传感器取代读数显微镜 ,把特定物体经透镜成像的大小转换为电信号的脉宽 ,并利用计算机技术自动处理测量数据 ,从根本上克服了用读数显微镜进行测量的缺陷 ,实现了航空相机镜头焦距的实时精确地在线测量     

Real-time distortion correction of fish-eye lens based on Bayer image signal

The imaging system based on a fish-eye lens generally has to correct the distortion of fish-eye images. The distortion correction based on the Bayer image signal is valuable, such as reducing the computation burden of image signal processing chips and providing a new imaging system structure of fish-eye lens. In this paper, a distortion correction method of fish-eye lens based on the Bayer image signal is proposed. Firstly, a distortion correction method that focuses on vertical straight lines and processing delay is proposed. Secondly, according to the correlation among color channels of the Bayer image, a novel Hermite interpolation method appropriate for Bayer image signal is proposed. Finally, a prototype system of fish-eye-lens-based imaging is established and the real-time field-programmable gate array (FPGA) implementation of the proposed method is demonstrated. The experiment demonstrates that the proposed distortion correction is not only characteristic of real-time processing and the smaller computation amount, but also applicable to embedded hardware.     

A lens hologram technique for analysing symmetrical aberrations of a camera system

A holographic technique is described whereby a 35 mm camera lens is used in conjunction with its own film to measure focusing errors and other symmetric aberrations. The method relies on photographing a scatter-plate whose fabrication is described. Results are presented showing how four different camera systems perform at various field angles.     

车载鱼眼成像系统的运动矢量检测方法

在复合成像侦测系统中,鱼眼成像系统的超大视场突破了"旋转扫描"和"多镜头拼接"的设计常规,采用固定凝视的方式对整个半球空域的目标进行搜索.然而在车载环境下,车体运动将导致输出的图像序列不稳定,影响观察效果,甚至会引起黄斑成像系统跟踪偏差.根据鱼眼成像系统的工作特点,通过利用熵值理论确定出图像信息最为丰富的区域,探讨了一...     

Compact zoom lens unit for camera phones

We present a novel approach to the miniaturization of an imaging system with high resolution and high optical magnification for camera phones. An optical zoom system with a mechanical shutter has been designed and developed, the mechanical shutter being necessary to assure high image quality. The shutter is integrated with the zooming lens group, which allows the zoom lens unit to be downsized. Performance of the zoom lens unit accommodates an image sensor of over five-mega-pixels and fulfills all the requirements of a camera phone.     

Compensation for reconstructed image distortion using camera model with lens distortion in incoherent digital holography

Optical Review - In incoherent digital holography (IDH), the reconstructed image may be distorted owing to lens aberration, which degrades image quality. A conventional camera lens is designed such...     

隐秘型CCD微摄像镜头光学设计

为了满足隐秘型ＣＣＤ摄像光学系统的广角视场、长工作距离、小空间尺寸、隐蔽性能好、成像质量优良等特殊要求。提出一种以同心透镜作为负组,置孔径光阑于镜头前方的新型反远摄结构。对其设计思想、像差特点进行了分析,并给出了ｆ′＝３６ｍｍ,２ω＝８０°,ｌＦ′／ｆ′＝１１的隐秘型ＣＣＤ微摄像镜头的像差和传函计算曲线     

面阵CCD摄像机光学镜头参数及其相互关系

主要介绍了用于面阵CCD摄像机的光学镜头参数 ,如焦距、光学格式、F数、景深、视场角、光圈和驱动及接口等。讨论了各项参数之间的相互关系。为合理选择不同CCD光学格式的镜头提供参考     

基于ZEMAX的手机摄像镜头设计

在光学工程软件ZEMAX的辅助下,配套采用像元大小为1.75μm的CMOS图像传感器,设计了一款500万像素的手机镜头,镜头视场角60°,F/#2.8,半像高2.87 mm,镜头总长为6 mm,镜头为3P1G结构,第1、3、4片镜片采用非球面塑料,第2片镜片采用球面透镜。各个视场的横向像差均小于20μm,均方根半径(RMS Radius)都在艾利斑之内,在1/2奈奎斯特频率处绝大部分视场MTF值都大于0.6,可以获得优质的成像效果。     

CCD camera system design for the beam diagnostic by using OTR

In this paper, a new CCD camera system used in the OTR beam measurement is presented, the basic principle of OTR beam measurement and the application of CCD chips-ICX208CL and AD9929 in camera system design are introduced in detail.     

Ultra-high-speed single red–green–blue light-emitting diode-based visible light communication system utilizing advanced modulation formats简

We propose an integral imaging system that uses three lens arrays, including two convex lens arrays and a concave lens array. Compared with the conventional integral imaging system, the proposed system can remarkably enhance the viewing angle. The maximum viewing angle can be enlarged to 48~, which is 4.8 times wider than that of the conventional system. The principle of the proposed system is elucidated, and the experimental results are presented in this letter.     

Viewing angle-enhanced integral imaging system using three lens arrays

We propose an integral imaging system that uses three lens arrays,including two convex lens arrays and a concave lens array.Compared with the conventional integral imaging system,the proposed system can remarkably enhance the viewing angle.The maximum viewing angle can be enlarged to 48°,which is 4.8times wider than that of the conventional system.The principle of the proposed system is elucidated,and the experimental results are presented in this letter.     

巧用数码相机使运动定格

许多实验过程持续时间短,速度快,不便于观察. 用数码相机的摄像功能摄录运动的全过程,再逐帧播放,即可清晰再现实验结果,便于客观准确地得出结论.