| 摘要 |
PURPOSE:To obtain a projection length in a short time by dividing the boundary line of an image into multiple straight lines, generating multiple graphics by means of the straight lines and detectors, adding the areas of the graphics containing image parts and subtracting the areas of the graphics which do not contain them. CONSTITUTION:The boundary line of the image is divided into the multiple straight lines and multiple graphics (trapezoids, for example) are formed by the straight lines and respective detectors. Then, the areas of respective graphics are obtained. The areas of the graphics containing the image parts are added and the areas of the graphics which do not contain the image part are subtracted. Such processing is executed for respective detectors. Thus, the areas of the image parts which are alloted to respective detectors, namely, the projection length can be obtained. Thus, the projection length can be obtained in a short time since Fourier transform and orthogonal polar coordinate transformation are not required. |
