Constructing cylindrical panoramic image using equidistant matching

An efficient algorithm for constructing cylindrical panoramic image mosaics from a near pure panning camera is proposed. The algorithm uses equidistant matching for image alignment which uses a translational motion model. It also allows the effective focal length of the camera to be estimated efficiently by a bisection method     

New chroma-key imagining technique with Hi-Vision background

An image synthesizing technique called Synthevision is described. In this approach to image synthesis, a line NTSC camera foreground picture is synchronously keyed into a background picture which is digitally processed from a wide Hi-Vision image. This background-derived picture is controlled by a computer using data from the foreground camera. If the camera image is altered by actions of zooming, panning, and focusing, the background picture is altered accordingly through the use of a newly developed digital image processor. The combined image thus exhibits a far greater realism than conventional chroma-key imaging. Synthevision is currently used at NHK for the evening news to change the background for each segment     

Thermal imaging with pyroelectric vidicons

The performance of a pyroelectric vidicon operating in either a panning or chopping mode is discussed. Some constraints on vidicon applications imposed by the nature of pyroelectricity are explored. Several means for advancement of pyroelectric vidicon technology are described. Finally, the projected performance of pyroelectric vidicons that incorporate these advances is discussed along with the performance of existing pyroelectric vidicons.     

Fast perceptual region tracking with coding-depth sensitive access for stream transcoding

Object-based bit allocation can result in significant improvement in the perceptual quality of extremely compressed video. However, real-time video object detection in large format high fidelity video is computationally daunting. Most algorithms begin with extensive use of classical bit analysis, and thus remain computationally heavy. Based on some recent results in human visual perception, in this paper, we present an experimental visual region tracking algorithm particularly designed for perceptual stream transcoding. This exploits the cue order observed in human visual perception to achieve very high computation speed as well as tracking efficiency. Rather than begin processing from pixel level or using any pixel level processing at all, it employs high level motion cue and block shape cue analysis to identify signatures of various relative movements between object of interest, scene background and the camera on the motion vector set, and from there it identifies objects. It then uses predictive filters to track the regions. The result is a fast yet highly effective perceptual region tracking algorithm that can operate in stream rate and track regions of perceptually significant object despite camera movements such as zoom, panning and translation. The technique is not specific to any special class of objects. We have implemented this algorithm in a live ISO-13818/MPEG-2 perceptual transcoder. In this paper, we share the performance of this implementation. This fast object-aware video rate transcoder is particularly suitable for live streaming and can convert a regular stream into a perceptually coded video stream.     

Joint Channel Coding Based on Principal Component Analysis

This paper proposes a new joint channel coding algorithm based on principal component analysis. A conventional joint channel coder using passive downmixing undergoes a reduction of both the primary‐to‐ambient energy ratio (PAR) of the downmix signal and the panning gain ratio of the primary source. The proposed system preserves the PAR of the downmix signal by using active downmixing which reflects spatial characteristic. The proposed system also improves the accuracy of the panning gain ratio estimation. Computer simulations and subjective listening tests verify the performance of the proposed system.     

Performance of interframe predictive coders for television signals under various conditions of motion

Subjective tests are reported, at 3 bits/pel, of the performance of several predictive coders for monochrome 625-line television signals under five different conditions of motion, including panning and scene changes. The results indicate that interframe prediction, used on a selective basis, can produce a worthwhile improvement in picture quality over that possible by intraframe prediction alone.     

Live RGB-D camera tracking for television production studios

In this work, a real-time image-based camera tracker is designed for live television production studios. The major concern is to decrease camera tracking expenses by an affordable vision-based approach. First, a dense keyframe model of the static studio scene is generated using image-based dense tracking and bundle adjustment. Online camera tracking is then defined as registration problem between the current RGB-D measurement and the nearest keyframe. With accurate keyframe poses, our camera tracking becomes virtually driftless. The static model is also used to avoid moving actors in the scene. Processing dense RGB-D measurements requires special attention when aiming for real-time performance at 30 Hz. We derive a real-time tracker from our cost function for a low-end GPU. The system requires merely a RGB-D sensor, laptop and a low-end GPU. Camera tracking properties are compared with KinectFusion. Our solution demonstrates robust and driftless real-time camera tracking in a television production studio environment.     

Hafnium tantalum nitride resistive sea for the silicon diode-array camera tube target

A new material has been developed as a resistive sea for the silicon diode-array camera tube target. The material is prepared by reactive sputtering of a hafnium tantalum cathode in a nitrogen atmosphere. By adjusting the relative amounts of hafnium and tantalum in the cathode or by changing the sputtering parameters, the resistivity of the hafnium tantalum nitride sea may be optimized. The nitride may be heated to 350°C during camera tube bakeout with no degradation in performance. By controlling the film deposition conditions, electrostatic focus camera tubes have been made with excellent aging, dark current, lag, and resolution characteristics.     

Edge-based 3-D camera motion estimation with application to videocoding

Two classes of algorithms for modeling camera motion in video sequences captured by a camera are proposed. The first class can be applied when there is no camera translation and the motion of the camera can be adequately modeled by zoom, pan, and rotation parameters. The second class is more general in that it can be applied when the camera is undergoing a translation motion, as well as a rotation and zoom and pan. This class uses seven parameters to describe the motion of the camera and requires the depth map to be known at the receiver. The salient feature of both algorithms is that the camera motion is estimated using binary matching of the edges in successive frames. The rate distortion characteristics of the algorithms are compared with that of the block matching algorithm and show that the former provide performance characteristics similar to those of the latter with reduced computational complexity.     

Teach by zooming: A unified approach to visual servo control

Traditionally, a visual servo control problem is formulated in the teach by showing framework with an objective to regulate a camera based on a reference (or desired) image obtained by a priori positioning the same camera at the desired task-space location. A new strategy is essential for a variety of applications where it may not be possible to position the camera a priori at the desired position/orientation. In this paper, a visual servo control approach, called “teach by zooming”, is formulated where the objective is to position/orient a camera based on a reference image obtained by another camera. For example, a fixed camera providing a wide area view of the scene can zoom in on an object and record a desired image for another camera. A non-linear Lyapunov-based controller is designed to regulate the image features acquired by an on-board camera to the corresponding image feature coordinates in the desired image acquired by the fixed camera in the presence of uncertain camera calibration parameters. The proposed control formulation becomes identical to the well-known teach by showing controller when the camera-in-hand can be located a priori to the desired position/orientation; thus enabling control in a wide range of applications. Experimental results for regulation control of a 7 degrees-of-freedom robotic manipulator are provided to demonstrate the performance of the proposed visual servo controller.     

Shot boundary detection in the presence of illumination and motion

Detection of gradual transition and the elimination of disturbances caused by illumination change or fast object and camera motion are the major challenges to the current shot boundary detection techniques. These disturbances are often mistaken as shot boundaries. Therefore, it is a challenging task to develop a method that is not only insensitive to various disturbances but also sensitive enough to capture a shot change. To address these challenges, we propose an algorithm for shot boundary detection in the presence of illumination change, fast object motion, and fast camera motion. This is important for accurate and robust detection of shot boundaries and in turn critical for high-level content-based analysis of video. First, the propose algorithm extracts structure features from each video frame by using dual-tree complex wavelet transform. Then, spatial domain structure similarity is computed between adjacent frames. The declaration of shot boundaries are decided based on carefully chosen thresholds. Experimental study is performed on a number of videos that include significant illumination change and fast motion of camera and objects. The performance comparison of the proposed algorithm with other existing techniques validates its effectiveness in terms of better Recall, Precision, and F1 score.     

Micro inspection robot for 1-in pipes

A micro inspection robot for 1-in pipes has been developed. The robot is 23 mm in diameter and 110 mm in length and is equipped with a high-quality micro charge-coupled device (CCD) camera and a dual hand for manipulating small objects in pipes. It can travel through both vertical pipes and curved sections, making possible inspections that would be difficult with conventional endoscopes. Its rate of travel is 6 mm/s and it has a load-pulling power of 1 N. To realize this microrobot, the authors have specially designed and developed several micro devices and micromechanisms: a novel micromechanism called a planetary wheel mechanism for robot drive; a micro electromagnetic motor with a micro planetary reduction gear to drive the planetary wheel mechanism; a micro pneumatic rubber actuator that acts as a hand; a micro CCD camera with high resolution; and a pneumatic wobble motor for rotating the camera and hands. In the paper, the design and performance of these micro devices are reported, the performance of the robot as a whole is described, and an application example is given     

某空间可见光相机的机身桁架结构设计

作为空间可见光相机的主要承载结构,机身桁架结构对于保证机身的力学性能至关重要。为了保证空间相机机身的结构刚度和稳定性,针对机身桁架结构设计进行了研究。研究了桁架的基本结构,分析了支杆力学性能的影响因素,探讨了支杆长度和角度对该机身桁架力学性能的影响。分析了支杆数量、支撑位置和分布形式对机身力学性能的影响,并分析了"△"型和"X"型桁架结构的特点。通过选择合理的支杆数量和分布形式,保证了机身桁架的力学性能。然后在设计分析的基础上进行了力学试验,验证了机身的力学性能。试验结果表明,该桁架结构的设计能够获得较好的力学性能,满足机身结构的设计要求。     

基于深度学习的单像素相机超分辨率成像优化

基于压缩感知和单像素成像的基本原理,设计了一种用于图像超分辨率重建的新型深度卷积神经网络架构.这种单像素超分辨率成像算法成功地将深度学习图像超分辨率重建技术与压缩感知单像素成像技术相结合,从而发展出一种全新的深度学习单像素成像优化方法.与传统的常规压缩感知图像重构算法相比,该算法有效提升了图像超分辨率重建精度和单像素成像质量.通过图像重建的仿真实验和单像素相机的成像实验验证,结果表明这种基于深度学习的新型单像素相机成像方式具有良好的性能表现.     

Broadband Sub-terahertz Camera Based on Photothermal Conversion and IR Thermography

This paper describes a fast sub-terahertz (THz) camera that is based on the use of a quantum infrared camera coupled with a photothermal converter, called a THz-to-Thermal Converter (TTC), thus allowing fast image acquisition. The performance of the experimental setup is presented and discussed, with an emphasis on the advantages of the proposed method for decreasing noise in raw data and increasing the image acquisition rate. A detectivity of 160 pW Hz^?0.5 per pixel has been achieved, and some examples of the practical implementation of sub-THz imaging are given.     

Phase unwrapping based on deep learning in light field fringe projection 3D measurement

Phase unwrapping is one of the key roles in fringe projection three-dimensional (3D) measurement technology. We propose a new method to achieve phase unwrapping in camera array light filed fringe projection 3D measurement based on deep learning. A multi-stream convolutional neural network (CNN) is proposed to learn the mapping relationship between camera array light filed wrapped phases and fringe orders of the expected central view, and is used to predict the fringe order to achieve the phase unwrapping. Experiments are performed on the light field fringe projection data generated by the simulated camera array fringe projection measurement system in Blender and by the experimental 3×3 camera array light field fringe projection system. The performance of the proposed network with light field wrapped phases using multiple directions as network input data is studied, and the advantages of phase unwrapping based on deep learning in light filed fringe projection are demonstrated.     

Rapid detection of camera tampering and abnormal disturbance for video surveillance system

Camera tampering may indicate that a criminal act is occurring. Common examples of camera tampering are turning the camera lens to point to a different direction (i.e., camera motion) and covering the lens by opaque objects or with paint (i.e., camera occlusion). Moreover, various abnormalities such as screen shaking, fogging, defocus, color cast, and screen flickering can strongly deteriorate the performance of a video surveillance system. This study proposes an automated method for rapidly detecting camera tampering and various abnormalities for a video surveillance system. The proposed method is based on the analyses of brightness, edge details, histogram distribution, and high-frequency information, making it computationally efficient. The proposed system runs at a frame rate of 20–30 frames/s, meeting the requirement of real-time operation. Experimental results show the superiority of the proposed method with an average of 4.4% of missed events compared to existing works.     

一种视频叠加芯片及其在摄象监视系统中的应用

文中介绍了字符叠加芯片SD01C01的性能特点及其在摄象监视系统中的应用。给出了固定字符叠加和可变字符叠加部分的硬件电路设计,采用纯硬件电路实现,无须使用单片机,无须软件编程。     

有侧向连接的Sanger算子在摄像机标定中的应用

为了求得摄像机的投影矩阵,在进行标定时,以采样点组合矢量坐标到由投影矩阵决定的超平面距离平方和为目标函数,设计有侧向连接的Sanger网络;采用自适应次分量的提取方法,以自相关矩阵最小特征值所对应的特征向量为超平面的拟合系数,据此求得摄像机的投影矩阵,完成摄像机的标定。根据摄像机的数学模型得到的投影点坐标与实际图像检测结果的图像残差均方值作为标定性能指标,进行精度分析。实验表明,所提出的方法是自适应Sanger算法在摄像机标定中的新应用。     

空间相机空间环境专项试验设计

为了确保空间相机在整个生存周期可靠地工作,根据空间环境的特点及空间相机的特性,提出了仿真空间相机空间环境的专项试验设计方案.方案包括光学性能验证试验,MTF性能测试,热真空环境下的温度调焦系数专项试验,考察碳纤维复合材料稳定性的结构性能验证试验,验证电子元器件是否满足相机功能和性能要求的电子学性能专项试验,验证活动机构...