Abstract: An image forming apparatus includes an image forming unit for forming an image on a sheet, mode setting unit for setting a test mode for a detection of a cause for a defect in the formed image, a control unit for causing the image forming means to form a plurality of sample images by changing operating conditions of the image forming unit when the test mode is set by the mode setting unit, an input unit for manually inputting a result of comparison of the plurality of sample images and display unit, wherein the control unit determines the particulars of the detection for the cause of the defect in the formed image or contents of the test mode to be subsequently carried out in response to an input of the input unit and, at the same time, causes the display unit to perform a display of the cause for the defect in the formed image or a display of the contents of the test mode to be subsequently carried out.

Abstract: An image processing apparatus includes an exposing lamp to expose an original, and a detector to detect the position and color of marker information marked by a predetermined color on the original which is exposed by the exposing lamp. A first determining circuit determines additional information which is added to the original image in accordance with the color of the marker information detected by the detector, and a second determining circuit determines the recording position of the additional information determined by the first determining circuit in accordance with the position of the marker information detected by the detector. An image forming device for synthesizing the original image and the additional information for recording on the same recording sheet.