“Image Correction for High Accurate Image Measurement with Digital Image”

The recent high advancement of CCD device is making quantitative image measurements practical in many areas. However, various kinds of distortions are included in the obtained image such as distortions due to the aberration of lens and inaccurate setting of camera posture (position and direction), which cannot be ignored for accurate measurement. In this paper we describe a method of correction of such distortions and treatment of digital image in the accuracy of sub-pixel order. Utilizing a high resolution CCD camera with more than six million photocells, we propose a correction method for image distortion caused by the lens' distortion and camera's angle of view can be obtained. We also experimentally verified that, the proposed method could achieve sub-pixel resolution with 4 times fidelity compared to the digital resolution of the camera.