Nonlinear Distortion Correction of Camera Based on Straight Lines

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 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 time-consuming process of coupling optimization involving distortion coefficients and camera external parameters is avoided. Therefore it has value.