An image processing system comprising: an image forming device configured to form an image based on print information, on a first conveyance medium; an information acquisition unit (131, 132, 307) configured to acquire information about the image formed on the first conveyance medium by the image forming device; an ejection control unit configured to control ejection of a second conveyance medium in a case where the image formed on the first conveyance medium is a defective image, based on the information acquired by the information acquisition unit (131, 132, 307); an ejection device (14,141) configured to stack the first conveyance medium and the second conveyance medium; a display control unit configured to control display of identification information that distinguishes and associates each one of a plurality of first conveyance media having defective images stacked on the ejection device (14,141), with a corresponding one of a plurality of second conveyance media stacked on the ejection device (14,141); and an ejection setting unit configured to receive a setting of an interval of ejection of the second conveyance medium, wherein the ejection control unit is configured to: in response to a determination that the image on the first conveyance medium is a defective image, hold ejection of the second conveyance medium in a case where the first conveyance medium having the defective image is to be ejected after ejection of the second conveyance medium and an insertion interval of the second conveyance medium is equal to or smaller than the interval of the setting received by the ejection setting unit; and cause the second conveyance medium to be ejected after the determination, in a case where the first conveyance medium having the defective image is to be ejected after ejection of the second conveyance medium and the insertion interval of the second conveyance medium is greater than the interval of the setting received by the ejection setting unit, and wherein the display control unit is configured to control display of information of a first conveyance medium having a defective image having been ejected after previous ejection of a second conveyance medium, in association with information of the second conveyance medium to be currently ejected. an image forming device configured to form an image based on print information, on a first conveyance medium; an information acquisition unit (131, 132, 307) configured to acquire information about the image formed on the first conveyance medium by the image forming device; an ejection control unit configured to control ejection of a second conveyance medium in a case where the image formed on the first conveyance medium is a defective image, based on the information acquired by the information acquisition unit (131, 132, 307); an ejection device (14,141) configured to stack the first conveyance medium and the second conveyance medium; a display control unit configured to control display of identification information that distinguishes and associates each one of a plurality of first conveyance media having defective images stacked on the ejection device (14,141), with a corresponding one of a plurality of second conveyance media stacked on the ejection device (14,141); and an ejection setting unit configured to receive a setting of an interval of ejection of the second conveyance medium, wherein the ejection control unit is configured to: in response to a determination that the image on the first conveyance medium is a defective image, hold ejection of the second conveyance medium in a case where the first conveyance medium having the defective image is to be ejected after ejection of the second conveyance medium and an insertion interval of the second conveyance medium is equal to or smaller than the interval of the setting received by the ejection setting unit; and cause the second conveyance medium to be ejected after the determination, in a case where the first conveyance medium having the defective image is to be ejected after ejection of the second conveyance medium and the insertion interval of the second conveyance medium is greater than the interval of the setting received by the ejection setting unit, and in response to a determination that the image on the first conveyance medium is a defective image, hold ejection of the second conveyance medium in a case where the first conveyance medium having the defective image is to be ejected after ejection of the second conveyance medium and an insertion interval of the second conveyance medium is equal to or smaller than the interval of the setting received by the ejection setting unit; and cause the second conveyance medium to be ejected after the determination, in a case where the first conveyance medium having the defective image is to be ejected after ejection of the second conveyance medium and the insertion interval of the second conveyance medium is greater than the interval of the setting received by the ejection setting unit, and wherein the display control unit is configured to control display of information of a first conveyance medium having a defective image having been ejected after previous ejection of a second conveyance medium, in association with information of the second conveyance medium to be currently ejected.