scholarly journals INFLUENCE OF MECHANICAL ERRORS IN A ZOOM CAMERA

2011 ◽  
Vol 22 (1) ◽  
pp. 21 ◽  
Author(s):  
Alfredo Gardel ◽  
Jose Luis Lazaro ◽  
Jean Marc Lavest
Keyword(s):  
Standard Deviation ◽  
Field Of View ◽  
Zoom Lens ◽  
Calibration Model ◽  
Lens System ◽  
Principal Point ◽  
Geometrical Modelling ◽  
Camera Parameters ◽  
Calibration Parameters ◽  
Pinhole Model

As it is well known, varying the focus and zoom of a camera lens system changes the alignment of the lens components resulting in a displacement of the image centre and field of view. Thus, knowledge of how the image centre shifts may be important for some aspects of camera calibration. As shown in other papers, the pinhole model is not adequate for zoom lenses. To ensure a calibration model for these lenses, the calibration parameters must be adjusted. The geometrical modelling of a zoom lens is realized from its lens specifications. The influence on the calibration parameters is calculated by introducing mechanical errors in the mobile lenses. Figures are given describing the errors obtained in the principal point coordinates and also in its standard deviation. A comparison is then made with the errors that come from the incorrect detection of the calibration points. It is concluded that mechanical errors of actual zoom lenses can be neglected in the calibration process because detection errors have more influence on the camera parameters.

Design of Zoom Lens System with Movable Components Including Large Aperture and with Ultra-Wide Field of View

2021 ◽  
Vol 58 (7) ◽  
pp. 0708001
Author(s):  
沈志娟 Shen Zhijuan ◽  
林海峰 Lin Haifeng ◽  
曹一青 Cao Yiqing
Keyword(s):  
Field Of View ◽  
Zoom Lens ◽  
Wide Field ◽  
Lens System ◽  
Large Aperture ◽  
Wide Field Of View

Three-component double conjugate zoom lens system from tunable focus lenses

2013 ◽  
Vol 52 (4) ◽  
pp. 862 ◽  
Author(s):  
Antonín Mikš ◽  
Jiří Novák
Keyword(s):  
Zoom Lens ◽  
Lens System

Design of Compact Infrared Zoom Lens System

2012 ◽  
Vol 571 ◽  
pp. 324-327
Author(s):  
A Qi Yan ◽  
Deng Shan Wu ◽  
Hao Wang ◽  
Jian Zhong Cao ◽  
Jing Jin Ma ◽  
...  
Keyword(s):  
Focal Plane ◽  
Low Cost ◽  
Optical Design ◽  
Focal Plane Array ◽  
Relevant Information ◽  
Commercial Application ◽  
Zoom Lens ◽  
Lens System ◽  
Compact Design ◽  
Infrared Materials

Infrared zoom lens system with cooled focal plane array (FPA) detector is widely used in military application. Relevant information about optical design can be got easily, but research on infrared zoom lens system with low cost and high image quality for commercial application is less. This paper design a Compact infrared zoom lens system with only four lenses, using an uncooled focal plane array (FPA) with 384×288 pixels with zoom ratio 3:1. Because of large F number and less lenses, transmission of the whole zoom system is greatly improved. NETD and MRTD of infrared system will be satisfying by this compact design. There is no special surface such as diffractive surface, HOE in zoom lens system, and only Ge and Znse infrared materials are chosen which result in lower production cost of infrared zoom lens system for commercial applications.

scholarly journals A New Model of RGB-D Camera Calibration Based On 3D Control Field

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5082 ◽  
Author(s):  
Zhang ◽  
Huang ◽  
Zhao
Keyword(s):  
3D Reconstruction ◽  
State Of The Art ◽  
Calibration Model ◽  
Control Field ◽  
New Model ◽  
Depth Images ◽  
Extrinsic Parameters ◽  
Relationship Model ◽  
Relative Pose ◽  
Calibration Parameters

With extensive application of RGB-D cameras in robotics, computer vision, and many other fields, accurate calibration becomes more and more critical to the sensors. However, most existing models for calibrating depth and the relative pose between a depth camera and an RGB camera are not universally applicable to many different kinds of RGB-D cameras. In this paper, by using the collinear equation and space resection of photogrammetry, we present a new model to correct the depth and calibrate the relative pose between depth and RGB cameras based on a 3D control field. We establish a rigorous relationship model between the two cameras; then, we optimize the relative parameters of two cameras by least-squares iteration. For depth correction, based on the extrinsic parameters related to object space, the reference depths are calculated by using a collinear equation. Then, we calibrate the depth measurements with consideration of the distortion of pixels in depth images. We apply Kinect-2 to verify the calibration parameters by registering depth and color images. We test the effect of depth correction based on 3D reconstruction. Compared to the registration results from a state-of-the-art calibration model, the registration results obtained with our calibration parameters improve dramatically. Likewise, the performances of 3D reconstruction demonstrate obvious improvements after depth correction.

scholarly journals EVN-Merlin Observations of the Remarkable Lens System: 2016+112

1996 ◽  
Vol 173 ◽  
pp. 339-340
Author(s):  
M.A. Garrett ◽  
S. Nair ◽  
D. Walsh ◽  
R.W. Porcas ◽  
A.R. Patnaik
Keyword(s):  
Field Of View ◽  
Wide Field ◽  
Common Elements ◽  
Lens System ◽  
Field Mapping ◽  
Mapping Techniques

2016+112 was observed simultaneously with the European VLBI Network (EVN) and MERLIN arrays during the May 1993 joint EVN-MERLIN session at λ18 cm. Common elements to both arrays included the Jodrell Bank 76-m Lovell and 32-m Cambridge telescopes. In order to simultaneously map the entire 4 arcsec2 field of view, various wide-field mapping techniques were employed (see Garrett et al. 1994b).

Evaluation of the Kodak Ektachem Glucose and Urea Methods

1980 ◽  
Vol 17 (6) ◽  
pp. 293-300 ◽  
Author(s):  
Penelope M S Clark ◽  
Larry J Kricka ◽  
Thomas P Whitehead
Keyword(s):  
Cerebrospinal Fluid ◽  
Analytical Methods ◽  
External Quality Assessment ◽  
Calibration Model ◽  
Tetraacetic Acid ◽  
Pleural Effusions ◽  
Serum Samples ◽  
External Quality ◽  
Control Serum ◽  
Calibration Parameters

An evaluation of the Kodak Ektachem glucose and urea methods is described. Aspects evaluated included precision, linearity, accuracy, correlation with routine methods, interferences (haemoglobin, bilirubin, protein, dextran, lipaemia, ethylene-diamine tetraacetic acid, fluoride/oxalate, and heparin), and carryover. Stability and batch-to-batch variation in glucose and urea reagents were also investigated. The performance of the Ektachem glucose and urea methods was shown to be as satisfactory as conventional analytical methods. The requirement to reconstitute control serum samples in a bicarbonate diluent in order to obtain accurate results presents problems for the analysis of lyophilised specimens circulated by external quality assessment schemes. The complex calibration model and the significance of variation in the calibration parameters need further explanation. The Ektachem methods are designed specifically for use with human serum. However, the methods performed satisfactorily with cerebrospinal fluid, pleural effusions, and animal serum but not with urine.

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