An apparatus for inspecting images is disclosed. In an embodiment an apparatus includes a camera for recording a surface of a printed product, the printed product being movable relative to the apparatus, a first illumination unit of a first type for illuminating a first partial region of a region that is capturable by the camera, a second illumination unit of a second type for illuminating a second partial region of the region that is capturable by the camera, and an evaluation unit for processing image information captured by the camera, wherein the first illumination unit differs from the second illumination unit, and wherein the first illumination unit forms a diffuse illumination source and has an internally illuminated tunnel.

A method for inspecting printed products of a machine for processing printing substrates includes recording and digitizing produced printed products by using at least one image sensor and analyzing the printed products by using a computer to find potential defects. Defects in the printed products are detected by the computer by comparing the recorded and digitized printed image with a digital reference image, analyzing occurring deviations, and marking defective printed products in a manner suitable for removal. The computer spatially subdivides every digitized printed image into regions with deviations, calculates the time required to analyze every one of the regions, and terminates the analysis of a digitized printed image when the time required to analyze the regions exceeds a predefined value of time per digitized printed image.

An inspecting apparatus for inspecting print images printed on a transparent printing medium. The apparatus includes a first transport roller for transporting the transparent printing medium; a second transport roller spaced from the first transport roller, and disposed downstream in a transport direction, for transporting the transparent printing medium; a photographing device for photographing the print images located in an inspection area; and a light emitting device for emitting light for photographing the print images located in the inspection area. The first transport roller and second transport roller have outer circumferential surfaces thereof each with a light absorbing member for absorbing the light from the light emitting device.

Provided are an inspection method, a program, an inspection device, and a printing device capable of realizing a uniform inspection in a defect inspection of a printed article using a special substrate. A method includes an imaging data acquisition step (S14) of acquiring imaging data (48) of a printed article using a special substrate, a non-printing region positional information acquisition step (S16) of acquiring information (44) for specifying a position of a non-printing region in the imaging data, the non-printing region corresponding to a substrate region of the printed article on which a pattern and a background of the pattern are not printed, an inspection step (S20) of specifying the non-printing region, analyzing the imaging data by applying a predetermined inspection rule (46), and performing an inspection of the printed article, and a notification step (S22) of performing a notification of an inspection result (50) and not performing a notification of an inspection result indicating that a defect is present in the substrate region of the printed article corresponding to the non-printing region.

A method is described in which a reflection is obtained of a laser light pattern reflected from a substrate. A reflection of diffuse light may be obtained from the substrate. A first parameter may be determined, relating to the substrate from the reflected laser light pattern. A second parameter may be determined, relating to the substrate from the reflected diffuse light and a characteristic of the substrate may be determined from the first and second parameters. A print apparatus and a machine-readable medium are also disclosed.

The present invention relates to a print quality inspection apparatus comprising: an illuminator (35 or 35A-35C) for irradiating light onto a printout (1) provided with a motion thread (1b); a camera (34 or 34A) for capturing an image of the printout; and a print quality inspection unit (10) for inspecting the print quality of the printout (1) on the basis of image data captured by the camera (34 or 34A). The camera (34) captures images of printouts (1) for each RGB color, and the print quality inspection unit (10) performs a print quality inspection having a scope that includes the motion thread (1b) on the basis of image data of a color of the same hue as the color of the motion thread (1b), or the illuminator (35A-35C) emits a color of the same hue as the color of the motion thread (1b), and the monochrome camera (34A) captures a monochrome image.

The invention relates to a method for verifying a printing plate, specifically a gravure cylinder, for errors in an engraving of the printing plate, comprising the following steps: Generating at least two proofs using a printing plate to be verified, capturing at least one digital image each of the at least two proofs with an image-capturing unit, comparing each of the digital images of the at least two proofs with the engraving template of the printing plate, wherein the comparison comprises the following steps: Detecting deviations between each of the images and the engraving template, and verifying that the detected deviations occur in identical fashion on the digital images of all of the at least two proofs, wherein a pseudo error is indicated if the comparison does not show identical deviations between the digital images of the at least two proofs, and wherein identical deviations indicate an engraving defect in the printing plate.

A quality control station (2) for a sheet element processing machine, the station having at least one camera (6) arranged for capturing images of sheet elements (4) transported through the quality control station (2), and further having a camera calibration system (10). The camera calibration system (10) having a target holder (12) for holding an optical target (14), and a drive (15) for the target holder (12). The drive (15) is adapted for displacing the target holder (12) between a rest position, in which it is outside of the viewing area (7) of the camera (6), and a calibration position in which it is arranged in the viewing area (7) of the camera (6).

A verification system for verification of a print output from a printing device includes at least one image recording device arranged spaced apart from the printing device. The printing device is configured to compute when a printed area passes the image recording device after a printing operation by a print head of the printing device, and generate a signal to the image recording device. The signal activates the image recording device to capture an image of a printed area and process the image for detecting, if the print out meets certain parameters.

The invention provides a press operator target for facilitating visual verification of colour accuracy in printed colour matter against an ideal colour proof. The invention also includes so-called Light/Master/Dark (“LMD”) standards for visually accessing colour variation that is acceptable in a particular print design and to aid a press operator in decision making in order to achieve a better proof to print match. Finally the aforementioned items are assembled into a colour proof assembly, which includes the press operator target, as well as the LMD standards.