Spherical approximation for multiple cameras in motion estimation: Its applicability and advantages

Estimating motions of a multi-camera system which may not have overlapping fields of view is generally complex and computationally expensive because of the non-zero offset between each camera’s center. It is conceivable that if we can assume that multiple cameras share a single optical center, and thus can be modeled as a spherical imaging system, motion estimation and calibration of this system would become simpler and more efficient.     

最新引进的高精度RMK-TOP航摄仪及其应用

本文主要介绍了高精度RMK－TOP航摄仪的主要部件及其技术性能和技术参数，以及该设备的主要技术特点和应用效果。     

Beyond pixels: Exploiting camera metadata for photo classification

Semantic scene classification based only on low-level vision cues has had limited success on unconstrained image sets. On the other hand, camera metadata related to capture conditions provide cues independent of the captured scene content that can be used to improve classification performance. We consider three problems, indoor-outdoor classification, sunset detection, and manmade-natural classification. Analysis of camera metadata statistics for images of each class revealed that metadata fields, such as exposure time, flash fired, and subject distance, are most discriminative for each problem. A Bayesian network is employed to fuse content-based and metadata cues in the probability domain and degrades gracefully even when specific metadata inputs are missing (a practical concern). Finally, we provide extensive experimental results on the three problems using content-based and metadata cues to demonstrate the efficacy of the proposed integrated scene classification scheme.     

ADV-JP2000及其在数码相机中的应用

ADV -JP2000是AnalogDevice公司为新的静止图像压缩标准JPEG2000而生产的专用压缩芯片 ,该芯片可灵活应用于各种静止图像压缩场合。文中主要介绍了ADV -JP2000的工作过程 ,给出了用ADV -JP2000为处理核心的数码相机系统的设计方案     

一个干涉图法波面位相自动探测

用Ｈｅ－Ｎｅ激光器作光源、ＣＣＤ摄像机－微机系统作探测器，应用一个干涉图法在泰曼干涉仪上实现了自动计算干涉图，不但再现了二维等高线图，而且获得了三维波面面形，作为实例，测试了玻璃平板的不平行度。     

Lens effect on synthetic image generation based on light particle theory

The synthetic image generation with the lens effect consists of two consecutive processors: the hidden-surface processor, and the focus processor. The normal ray-tracing algorithms are used in the first processor. The second processor computes Lommel's function, which is an infinite series of Bessel functions. In order to avoid the complicated calculation and the huge memory consumption, an approximation method based on the light particle theory is developed. No noticeable differences can be detected between the results from the approximation method and those from the exact calculation.     

A Fractional-N CMOS DPLL with Self-Calibration

A digital phase-locked loop (DPLL) based on a new digital phase-frequency detector is presented.The self-calibration technique is employed to acquire wide lock range,low jitter,and fast acquisition.The DPLL works from 60 to 600MHz at a supply voltage of 1.8V.It also features a fractional-N synthesizer with digital 2nd-order sigma-delta noise shaping,which can achieve a short lock time,a high frequency resolution,and an improved phase-noise spectrum.The DPLL has been implemented in SMIC 0.18μm 1.8V 1P6M CMOS technology.The peak-to-peak jitter is less than 0.8% of the output clock period and the lock time is less than 150 times of the reference clock period after the pre-divider.     

导光板模具微冲孔机床在位测量系统的设计与研究

针对导光板模具微结构加工过程中微孔尺寸定时在位测量的要求,基于视觉测量技术提出了在微冲孔机床上集成导光板模具微孔点阵在位测量系统的解决方案。它通过相机获取微结构的加工图像,运用一系列图像处理算法提取测量目标的亚像素边缘并进行拟合。提出两步标定技术求取亚毫米视野镜头畸变映射及像素当量。通过将视觉测量结果与白光干涉仪的测量结果对比,证明该测量系统的精度能够达到±1μm以内,具有实时、快速、高精度、重复性好的等特点。     

全网络数字视频监控系统在实际工程中的应用

随着全网络数字监控系统在楼宇监控、平安城市等大型项目中的广泛应用,相对于传统模拟监控系统而言,基于720P、1080P等超百万像素高清网络数字摄像机的视频监控系统优势明显,所带来的视觉震撼和强大功能是传统模拟视频监控系统无法比拟的。依托于比较成熟的网络技术,全网络数字视频监控系统有效地解决了长距离布线、系统的扩展等问题。本文以百度机房工程为例介绍了其视频安防监控系统实施方案。     

摄像机空中轨道拍摄控制系统设计

根据摄像机在空中轨道的拍摄需求,设计了一种由伺服电机驱动摄像机实现俯仰摇移运动功能的控制系统。所设计控制系统的硬件包括伺服电机、无线数传模块和控制摇杆等相关设备,控制平台由基于LabVIEW2012开发的软件系统实现。通过仿真和实验证明,该控制系统具有定位准确、响应迅速、操作简单等特点,为实现摄像机在空中轨道的稳定拍摄提供了可靠保证。