수치사진측량에 스마트폰 카메라의 활용 가능성 평가

Abstract

Recently high resolution CCD(charge-coupled device) and CMOS(complementary mental-oxide-semiconductor) sensor to the development of photogrammetry to utilization of high resolution non-metric camera is increasing. So high resolution camera image is provided to smartphone camera. This study aimed to analyze the accuracy of the images of smartphone to determine three-dimension position of photogrammetry prior to the development of photogrammetric system applying smartphone and evaluate the feasibility to use. First of all, prior to the accuracy assessment of smartphone camera, camera calibration was conducted to correct lens distortion of each camera and camera calibration of distortion coefficients is used to distortion model of balance system and the accuracy of image coordinates and object coordinates calculated by bundle adjustment during this procedure was analyzed. The results of calibration on 8 types of projects showed that all cases were in RMS error by less than 1 mm from bundle adjustment. And camera calibration was conducted on autofocus and infinite focus. In terms of autofocus and infinite focus on S model, the pattern of distorted curve was almost the same, so it could be judged that change in distortion pattern according to focus mode is very little. Lastly the checkpoint performance by total station was fixed as most probable value and the checkpoint performance determined by each project was fixed as observed value to calculate statistics on residual of individual methods. The result showed that all projects had relatively large errors in the direction of X, the direction of object distance compared to the direction of Y and Z. As mentioned above, in terms of accuracy for determination of three-dimension position, the feasibility to use smartphone camera would be enough.