An image inspection device analyzes data of a first read image obtained by reading a defective nozzle detection pattern which is recorded in a first region of a recording medium by a single pass ink jet printing apparatus to detect a defective nozzle of a line-type ink jet head used to record the defective nozzle detection pattern and stores a history of the detection result of the defective nozzle in a history information storage unit. The image inspection device analyzes data of a second read image of a printed image recorded in a second region of the recording medium to detect an image defect of the printed image and collates information about the detected image defect with history information stored in the history information storage unit to specify a defective nozzle causing the image defect.

A method for processing print data includes a matching processing step of performing pattern matching between a streak detection pattern including a streak pattern having a width of one pixel and print data after a RIP process, a length measurement step of determining, when matching is established in the matching processing step, a length of a streak candidate part including a part corresponding to the streak pattern in a region where matching is established and a part continuous in an extending direction of the streak pattern and having a same value as a data value of the streak pattern, in the print data, and a determination step of determining whether or not the streak candidate part is white streak data that possibly results in a streak, by comparing the length determined in the length measurement step against a predetermined threshold.

An image inspection device analyzes data of a first read image obtained by reading a defective nozzle detection pattern which is recorded in a first region of a recording medium by a single pass ink jet printing apparatus to detect a defective nozzle of a line-type ink jet head used to record the defective nozzle detection pattern and stores a history of the detection result of the defective nozzle in a history information storage unit. The image inspection device analyzes data of a second read image of a printed image recorded in a second region of the recording medium to detect an image defect of the printed image and collates information about the detected image defect with history information stored in the history information storage unit to specify a defective nozzle causing the image defect.

A defect inspection apparatus includes a first slit light source together with a machine base in which a through hole is formed. A second slit light source and a half mirror are provided inside the through hole. First slit light from the first slit light source is directly incident on an object to be photographed (for example, an automobile body). On the other hand, second slit light from the second slit light source proceeds in a direction perpendicular to the direction in which the first slit light proceeds, and thereafter, is refracted by the half mirror, led out from the through hole, and made incident on the object to be photographed.

Systems and techniques are described for detecting surface profile defects within a moving web. An example system includes a conveyor configured to translate the web, along a downweb direction and at a translation speed, relative to an inspection area; a point light source configured to emit light, wherein the point light source is positioned and oriented relative to the conveyor to illuminate a portion of the web positioned within the inspection area; a diffusing screen positioned and oriented relative to the conveyor to receive the light reflected from the web as the web is translated through the inspection area; an image capture device configured to capture images of the diffusing screen; and a computing device configured to: identify, based on the images, a surface profile defect in a surface of web; and output data indicating a relative location of the defect within the web.