Image inspecting apparatus and image forming apparatus

An image forming apparatus, comprising:

• an image forming portion configured to form an image on a sheet;
• a scanner configured to irradiate, with light, a sheet surface of a sheet formed with a reference image for alignment by the image forming portion and to obtain image data by reading the sheet surface by receiving light reflected on the sheet surface;
• a storage configured to previously store a first correlation between an edge-blur amount of a rising edge portion and/or a falling edge portion of the image data obtained using the scanner and a distance from a focal point of the scanner to the sheet surface;
• and
• a hardware processor configured to measure a distance between a reference position and a reference image on the sheet surface read by the scanner, and to correct an image forming position of the sheet in accordance with the distance, wherein
• the hardware processor is further configured to calculate the edge-blur amount from the image data obtained by the scanner, to calculate heights of the reference position and the reference image, using the focal point of the scanner as a base point on the basis of the calculated edge-blur amount and the first correlation stored in the storage, to calculate a distance between the reference position and the reference image on the sheet surface by using the heights of the reference position and the reference image and the distance between the reference position and the reference image in a sheet conveying direction, and to control the image forming portion to output the image on the sheet at the corrected image forming position based on the distance between the reference position and the reference image.