| 摘要 |
An image-forming apparatus forms a test image on a sheet being transported. The test image includes a defect detection image for image defect detection and a plurality of marks for detecting the angle of inclination of the test image on the sheet in a two-dimensional plane extending in a transport direction of the sheet and a width direction of the sheet crossing the transport direction. The plurality of marks are formed at positions remote from each other in a central region of the sheet in the width direction. The image-forming apparatus then reads the test image, detects the plurality of marks, calculates the angle of inclination of the test image based on the plurality of marks, corrects the test image for inclination based on the calculated angle of inclination, and detects an image defect based on corrected-image data representing the corrected test image. |
