Application of direct linear transform for calibration of miniature computed tomography

After the development of miniature computed tomography, the calibration is the first thing to do. In this paper, image processing was used for testing miniature CT. We got comprehended coordinates on a chessboard. Then entire data were computed by direct linear transform equation (DLT). DLT is famous equation for finding a real position of three-dimensional object form two-dimensional images in multi projections. Afterward, rotation metric and transition metric of a camera was calculated by DLT. These metric can describe about the circular structure of gantry, flatness of gantry plane and accuracy of rotation angle. These parameters are especially important in reconstruction of cross sectional images by Feldkamp algorithm. Stability of miniature CT helps to reduce the artifacts in the image so good quality x-ray images can be derived.