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This work will discuss the design of a high linearity, low dispersion injection circuit to be used for pixel-level calibration of detector readout electronics. In hybrid pixel detectors, the circuit provides a useful means for precise analog test of the pixel cell unit already at the chip level, when no sensor is connected or the detector has been connected to the chip. Moreover, it provides a simple...
An easy way to achieve higher depth of field in a camera-laser configuration is to tilt the image sensor respect to the lens plane, such that the image plane, laser plane and the lens plane intersect in a unique line (Scheimpflug condition [1]). If something has to be measured with this kind of cameras, a proper camera calibration must be done. The usual calibration methods are not valid in this case...
In this paper we construct a long-distance VGA signal extending system featuring the self-tuning capability. The physical carrier of the signal is the typical local area network (LAN) cables such as CAT-5e. By investigating the noise distributions over the carrier a video restoration algorithm is proposed. The algorithm calculates the associated statistics and identifies the optimal IC control parameters...
We present a multi-view 3D video acquisition and its processing system for multi-view 3D television (3DTV). The proposed hybrid camera system consists of three-color cameras and one time of flight (TOF) camera. Since currently available TOF cameras do not provide color images associated with the depth image, we use a beam splitter between the color camera of the center view and the TOF camera to minimize...
PMD camera is an active 3D camera based on TOF principle. This camera can capture intensity image and depth map at the same time and also has advantages of high frame rate, non-scan and independence on ambient light, etc. But the depth data are contaminated by random noise and systematic bias. To solve this problem, this paper analyzes the factors that affect the precision of distance data and presents...
To satisfy the demand of the real-time computer vision system, a method of camera calibration was analysed. According to the camera model from OpenCV(Intel Open Source Computer Vision Library), with radial aberration and tangential aberration considered, Zhang's arithmetic of camera calibration was applied. As the experimental result showed, the arithmetic exerted OpenCV library function at a great...
3D Time-of-Flight cameras are able to deliver robust depth maps of dynamic scenes. The frame rate, however, is limited because today's systems utilizing two-tap sensors need to acquire the required raw images in multiple instances in order to compute one depth map. These multiple raw images allow canceling out systematic errors introduced by asymmetries in the two taps, which otherwise would distort...
In recent years, there has been increased interest in characterizing and extracting 3D information from video sequences for object tracking and identification. In this paper, we propose a single view-based framework for robust estimation of height and position. In this work, 2D features of a target object is back-projected into the 3D scene space where its coordinate system is given by a rectangular...
Currently, the price of digital camera is decreasing and many users afford to purchase it. The digital camera can be used for many applications. The digital camera can also be used for accurate measurement such as determination of three dimensional (3D) coordinates, production of accurate measurement and generation of 3D model of objects. However, the digital camera need to be calibrated to obtain...
We introduce a general technique for blending imagery from multiple projectors on a tracked, moving, non-planar object. Our technique continuously computes visibility of pixels over the surfaces of the object and dynamically computes the per-pixel weights for each projector. This approach supports smooth transitions between areas of the object illuminated by different number of projectors, down to...
Recently, there are many autonomous navigation applications done in outdoor environment. However, safe navigation is still a daunting challenge in terrain containing vegetation. Thus, a study on vegetation detection for outdoor automobile navigation is investigated in this work. At the early state of our research, we focused on the segmentation of LADAR data into two classes by using local three-dimensional...
A measurement system is designed and produced to map the flux density of concentrated solar radiation in the focal plane of solar furnace with an indirect method. It includes a Lambertian moving bar, a CCD-camera and flux gauges. The movement of the bar and the image taking and processing are controlled by a computer. An integrated gray image which indicates the relative value of the radiation flux...
The parameter estimation variance of the Single Point Active Alignment Method (SPAAM) is studied through an experiment where 11 subjects are instructed to create alignments using an Optical See-Through Head Mounted Display (OSTHMD) such that three separate correspondence point distributions are acquired. Modeling the OSTHMD and the subject's dominant eye as a pinhole camera, findings show that a correspondence...
This paper presents an analysis of multiple size region of interest in selected area or segment of disparity mapping in application of stereo vision. The mapping is about to deal with the intensities of pixels which allocate the depths of an image and can be extracted to get the distance values. This region is a reference view of the stereo camera and stereo vision baseline is based on horizontal...
This paper presents a new real-time fish-eye distortion correction algorithm based on Midpoint Circle Algorithm with application in IP network camera. In particular, our method is no need of a planar checkerboard, iterative fitting of model parameters, complex computation, or traditional lookup table. Hence, our algorithm is very suitable for embedded camera platform without any extra hardware resources.
To solve the problem of precise edge localization and measurement on low-resolution images, statistics characters of edge gradient magnitude of both high and low resolution images along the gradient direction are extracted and analyzed. The gradient magnitude statistics is described with General Gaussian Distribution (GGD). The relationship between statistics of high and low resolution images is established...
A image processing engine, which performs halftoning and calibration of nonlinear optical response for electrophoretic displays (EPDs), is proposed. The engine processes images according to temperature dependent characteristics of EPDs for getting better visual quality.
In the planar measurement based on image, the size of objects' image cannot keep linearity with their real size due to the aberration of lens and CCD. This paper use a new simple method to eliminate them. Firstly, the coordinate system are set and their transforms are modeled. Then, a separating parameter method is provided to simplified the course of measurement. So several separated parameters needed...
Wheel set wear online measurement is important for the safety running of train vehicle. Measuring principle based on structure light imaging and machine vision was put forward. The main components included structure light source, CCD and wheel detector. Calibration error of CCD and wheel detector will greatly influence the precision of the wear measurement. A calibration system was designed for the...
A lane-departure detection system without intrinsic and extrinsic camera parameters calibration is proposed in this paper. The proposed system, which provides driving safety by lane detection and lane departure warning, is focused on urban road with complicated lane marks instead of simple highway scenes. Due to the complexity of urban traffic scenes, false lane detections are highly caused by warning...
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