Abstract: A method is used for inspecting at least one copy of a printed product. At least one element, which is spatially constant with respect to a fixed reference point and at least one element which is spatially variant with respect to the same fixed reference point are reliably inspected by reference image data being used for a desired-actual value comparison of the at least one spatially variant element. The reference image data takes account of the variable position of the at least one element; i.e. the spatial variance thereof.

Abstract: A method is used for inspecting at least one copy of a printed product. At least one element, which is spatially constant with respect to a fixed reference point and at least one element which is spatially variant with respect to the same fixed reference point are reliably inspected by reference image data being used for a desired-actual value comparison of the at least one spatially variant element. The reference image data takes account of the variable position of the at least one element; i.e. the spatial variance thereof.

Abstract: A method for controlling the quality of printed documents, such as banknotes, in which only part of the surface of the printed documents is available for inspection, comprising the steps of (i) storing a reference image; (ii) acquiring a sample image of a sample printed document to be controlled, which sample image covers only a limited portion of the sample printed document; (iii) selecting a search pattern within the acquired sample image; (iv) searching the reference image for a match with the selected search pattern, (v) determining control parameters linked to the position of the search pattern within said sample image and within said reference image, (vi) comparing the control parameters linked to the position of the search pattern within the sample image with the control parameters linked to the position of the search pattern within the reference image; and (vii) based on the results of the comparison of the control parameters, accepting or rejecting the sample printed document.

Abstract: A method for controlling the quality of printed documents, such as banknotes, in which only part of the surface of the printed documents is available for inspection, comprising the steps of (i) storing a reference image; (ii) acquiring a sample image of a sample printed document to be controlled, which sample image covers only a limited portion of the sample printed document; (iii) selecting a search pattern within the acquired sample image; (iv) searching the reference image for a match with the selected search pattern, (v) determining control parameters linked to the position of the search pattern within said sample image and within said reference image, (vi) comparing the control parameters linked to the position of the search pattern within the sample image with the control parameters linked to the position of the search pattern within the reference image; and (vii) based on the results of the comparison of the control parameters, accepting or rejecting the sample printed document.

Abstract: A system is provided for inspecting a printed image. The system is provided with at least one evaluation unit, a display device and an image scanner. That scanner takes an image that represents, at least partially, a printed image. The copied printed image belongs to a sequence of images printed on a print carrier by a printing machine. The evaluation unit receives data that is correlated to an image which has been taken, and evaluates that data by comparing it with recorded data of at least one preceding image, or with a reference image. The display device is provided with a graphic display surface that is comprised of several areas which are controlled, in a different manner, by the evaluation unit, and which are preferably simultaneously displayed. A first area displays several images, such as the just taken image, the preceding image and the reference image.

Abstract: A material, with at least one identification characteristic, is subjected to a qualitative evaluation. A color image of this at least one identification characteristic is taken using an electronic image sensor which produces an electrical signal that is evaluated by an evaluation device. Another electrical signal is obtained from at least one reference image and is stored in a data memory. The second electric signal, has a set point value, for the first electric signal, for at least two set point values contained in the reference image. The first signal is compared to at least two set point values in the second image. The color image of the identification characteristic is tested for deviation from the reference. The identification characteristic is checked for association with at least one aspect of the identification characteristic of the material. The tasks are carried out in a continuous working process being carried out by a machine, such as a printing machine, during a continuous printing process.

Abstract: A method for qualitatively evaluating material with at least one identification characteristic, whose position can vary within an expectation range designated by tolerance limits, involves the use of at least one illuminating device, at least one photoelectric sensor and an evaluating device. At least one background reference value and at least one mask reference are stored in the evaluating device. The background reference represents the characteristics of a printed image, particularly the gray scale value, in at least one portion which surrounds the identification characteristic. The mask reference represents the geometrical contour of the identification characteristic. During inspection of the printed material, differential image data is found, at least from the expectation range, from the actual image data, and from the background reference value in the evaluating device. The actual position of the identification characteristic is subsequently derived in the evaluating device.

Abstract: A material, with at least one identification characteristic, is subjected to a qualitative evaluation. A color image of this at least one identification characteristic is taken using an electronic image sensor which produces an electrical signal that is evaluated by an evaluation device. Another electrical signal is obtained from at least one reference image and is stored in a data memory. The second electric signal, has a set point value, for the first electric signal, for at least two set point values contained in the reference image. The first signal is compared to at least two set point values in the second image. The color image of the identification characteristic is tested for deviation from the reference. The identification characteristic is checked for association with at least one aspect of the identification characteristic of the material. The tasks are carried out in a continuous working process being carried out by a machine, such as a printing machine, during a continuous printing process.

Abstract: A system is provided for inspecting a printed image. The system is provided with at least one evaluation unit, a display device and an image scanner. That scanner takes an image that represents, at least partially, a printed image. The copied printed image belongs to a sequence of images printed on a print carrier by a printing machine. The evaluation unit receives data that is correlated to an image which has been taken, and evaluates that data by comparing it with recorded data of at least one preceding image, or with a reference image. The display device is provided with a graphic display surface that is comprised of several areas which are controlled, in a different manner, by the evaluation unit, and which are preferably simultaneously displayed. A first area displays several images, such as the just taken image, the preceding image and the reference image.

Abstract: A method for qualitatively evaluating material with at least one identification characteristic, whose position can vary within an expectation range designated by tolerance limits, involves the use of at least one illuminating device, at least one photoelectric sensor and an evaluating device. At least one background reference value and at least one mask reference are stored in the evaluating device. The background reference represents the characteristics of a printed image, particularly the gray scale value, in at least one portion which surrounds the identification characteristic. The mask reference represents the geometrical contour of the identification characteristic. During inspection of the printed material, differential image data is found, at least from the expectation range, from the actual image data, and from the background reference value in the evaluating device. The actual position of the identification characteristic is subsequently derived in the evaluating device.