Nonlinear Distortion Correction of Camera Based on Straight Lines

Zhang Zhengyu, Huang Xuhui, Ying Jiang, Zhou Run
2017 DEStech Transactions on Engineering and Technology Research  
Nonlinear distortion correction of camera is used to promote the photogrammetric accuracy. According to the principle which a straight line in three-dimensional space projecting on the CCD plane of camera remains a straight line, a nonlinear distortion correction method based on straight lines is proposed. Experimental results have demonstrated that the nonlinear distortion coefficients are gradually converged to the correct result, with the increase of uniform distribution of the selected
more » ... f the selected straight lines on the CCD. This method does not require the high-cost calibration plate, as well as the camera external parameters, only using the straight lines in the photos, and the timeconsuming process of coupling optimization involving distortion coefficients and camera external parameters is avoided. Therefore it has value. KEYWORDS machine vision; photogrammetry; camera calibration; distortion correction INSTRUCTIONS The camera optical system is not an ideal pin-pole model, there existing problems like the lens distortion, distort the central of photography and collinear relationship between the measuring point, its imaging point and center of camera lens etc. The camera calibration can be used to get the distortion coefficients, and it is divided into the three kinds [1] [2] [3][4][5][6][7][8][9][10][11][12][13] . The first is based on collinear equation [1] [2] [3] . It needs high precision calibration object whose surface is printed many points whose accuracy 3D coordination is known to stablish the constraint relationship following collinear equation to solve the image distortion coefficients and external parameters of camera, but as the width of a calibration plate more than 400mm, its manufacturing and storage maintenance costs increase significantly. This kind of method includes Tsai's two-step calibration [7] , the iterative method proposed by Weng [8] and Martin [9] 's double plane calibration [13] .
doi:10.12783/dtetr/mcemic2016/9538 fatcat:wiqsbw6m65hfxndx4hdppnlgjq