Abstract: The disclosed method and apparatus execute a printing step for setting a printing condition concerning at least one of a printing machine, a dot pattern, printing paper and ink, and printing an image having a plurality of different dot percentages with the printing condition set; a profile creating step for creating a profile showing printing stability in form of a relationship between the printing condition and each of the dot percentages by measuring a print image obtained in the printing step; a calculating step for deriving printing stability for each color area of an image to be printed, from image data of the image to be printed, the printing condition in time of printing and the profile; and a displaying step for displaying the printing stability of each color area, obtained in the calculating step, of the image to be printed.

Abstract: An ink feeding method for a printing machine includes a first color density measuring step for measuring color density of prints at selected times, an expected color density computing step for computing, based on the color density of prints measured in the first color density measuring step, an expected color density of prints occurring after a predetermined number X of prints are made, an ink feeding rate correcting step for correcting the ink feeding rate based on the expected color density of prints computed in the expected color density computing step and a target color density of prints, a second color density measuring step for measuring color density of an Xth print in the predetermined number X of prints after the ink feeding rate is corrected, and a number of prints correcting step for varying the predetermined number X of prints based on the color density measured in the second color density measuring step and the target color density of prints.

Abstract: An ink feeding method for a printing machine includes a first color density measuring step for measuring color density of prints at selected times, an expected color density computing step for computing, based on the color density of prints measured in the first color density measuring step, an expected color density of prints occurring after a predetermined number X of prints are made, an ink feeding rate correcting step for correcting the ink feeding rate based on the expected color density of prints computed in the expected color density computing step and a target color density of prints, a second color density measuring step for measuring color density of an Xth print in the predetermined number X of prints after the ink feeding rate is corrected, and a number of prints correcting step for varying the predetermined number X of prints based on the color density measured in the second color density measuring step and the target color density of prints.

Abstract: A print defect displaying method for displaying a defect on prints based on image data obtained by successively reading images from the prints. The method includes a first imaging step for obtaining first image data having a first resolution by reading an image from a first print, a defect detecting step for detecting a defect on the prints by comparing the image data obtained in the first imaging step and reference image data, a second imaging step for obtaining second image data having a second resolution higher than the first resolution, by reading an image from an area, including the defect detected in the defect detecting step, on a second print produced after the first print, and an enlarged image displaying step for displaying in enlargement the area including the defect based on the second image data.

Abstract: A tone control method for controlling tones of prints includes a control point selecting step for selecting, based on reference image data, a control point for use in controlling the tones of prints; a first obtaining step for obtaining information on an area around the control point in the reference image data as first area information; a second obtaining step for obtaining information on an area around a control point in the read image data, corresponding to the control point in the reference image data, as second area information; a determining step for determining whether the control points are proper, by comparing the first area information and second area information; and a tone control step for controlling the tones of the prints based on color information on the control points when the control points are determined proper in the determining step.

Abstract: A representative point determining method for determining representative points to be compared when adjusting color tones of a print made by a printing machine, by comparing image data serving as a reference and image data obtained by reading an image on the print. The method includes a representative point setting step executed by an operator for setting a representative point to at least one of a plurality of areas corresponding to ink keys of the printing machine, and a representative point determining step for determining representative points for other areas corresponding to the ink keys based on the representative point set by the operator and by using setting conditions for setting representative points to the other areas.

Abstract: A tone control method for creating data for controlling ink feeding rates of a printing machine, by comparing image data serving as a reference and image data obtained by reading an image from an actual print. The method includes a control point determining step for determining a plurality of control points for each area corresponding to ink keys in each ink well of the printing machine, a weight factor calculating step for calculating a weight factor of each of the control points determined in the control point determining step, by using a color spread of each control point, a color purity of each control point and a dot percent of each control point, and a calculating step for calculating color values for controlling the ink feeding rates, by totaling, for all of the control points, products of the color values and the weight factor of each of the control points.

Abstract: In a job selecting step executed in parallel to a printing step, a display screen 100 displays, in a setting window 201 appearing in an upper portion thereof, a plurality of job data 103a, 103b, 103c and 103d downloaded from a RIP 102 and stored in a printing machine, along with various setting keys 221. The operator selects job data for a next printing process from among these job data 103a, 103b, 103c and 103d. At this time, a printing state window 202 is displayed in a lower portion of the display screen 100. This printing state window 202 is a screen constantly displayed during printing processes.

Abstract: An ink feeding method for a printing machine includes a first color density measuring step for measuring color density of prints at selected times, an expected color density computing step for computing, based on the color density of prints measured in the first color density measuring step, an expected color density of prints occurring after a predetermined number X of prints are made, an ink feeding rate correcting step for correcting the ink feeding rate based on the expected color density of prints computed in the expected color density computing step and a target color density of prints, a second color density measuring step for measuring color density of an Xth print in the predetermined number X of prints after the ink feeding rate is corrected, and a number of prints correcting step for varying the predetermined number X of prints based on the color density measured in the second color density measuring step and the target color density of prints.

Abstract: An ink feeding method for a printing machine includes a color density measuring step for measuring color density of prints at intervals of time, a variation coefficient computing step for computing a variation coefficient for varying the ink feeding rate based on the color density of prints and a target color density of prints, a color density gradient computing step for computing, based on the color density of prints, a color density gradient representing a rate of variation in the color density of prints occurring with an increase in the number of prints, an expected color density computing step for computing, based on the color density gradient, an expected color density of prints occurring after a predetermined number of prints are made, a determining step for determining whether the expected color density of prints occurring after the predetermined number of prints are made exceeds the target color density of prints, and a variation coefficient correcting step for correcting the variation coefficient whe

Abstract: A representative point determining method for determining representative points to be compared when adjusting color tones of a print made by a printing machine, by comparing image data serving as a reference and image data obtained by reading an image on the print. The method includes a representative point setting step executed by an operator for setting a representative point to at least one of a plurality of areas corresponding to ink keys of the printing machine, and a representative point determining step for determining representative points for other areas corresponding to the ink keys based on the representative point set by the operator and by using setting conditions for setting representative points to the other areas.

Abstract: A color chart is printed by each of multiple printers A, B, C based on the same color chart data. The printed color charts (401) are then measured using a colorimeter (110) to acquire color measurement data DA, DB, DC corresponding respectively to printers A, B, C. A profile generator (100a) then generates a profile using this color measurement data DA, DB, DC by applying an averaging operation to the color measurement data DA, DB, DC to generate average color measurement data Davg. The color measurement data DA, DB, DC and average color measurement data Davg are then displayed for evaluation by the operator, who determines whether reprinting the color chart is necessary. If reprinting is not necessary, a common profile (405) describing color reproduction by the printers A, B, C is generated based on the average color measurement data Davg. The resulting common profile is then used for color correction of image data to be used for printing in a prepress printing system comprising the printers A, B, C.

Abstract: A printed sheet measurement apparatus initially captures images on a reference sheet and a printed sheet to store respective image data. Next, both of the image data are displayed on a display element, and a pair of corresponding points are specified for each of the image data. A judgment is made as to whether or not the pair of corresponding points on each of the images are spaced at least a predetermined distance apart from each other. If not, the corresponding points are specified again. After the corresponding points are determined, the coordinates of the corresponding points are stored. The coordinates of an objective point at which a colorimetric value is to be computed is computed based on the corresponding points. Next, a colorimetric value on the coordinates is measured.

Abstract: In an initial state, a key control switch for adjusting opening degrees of ink keys and a display changeover switch are displayed on a display screen of a touch sensitive control panel. The key control switch is a collection of key control switches individually arranged in areas corresponding to the ink keys, and for each ink color. The individual key control switches indicate color densities of control strips on a print measured by a color density measuring device and the opening degrees of the ink keys. When the changeover switch is operated in this state, the control panel simultaneously displays the key control switches and an image of the print being processed.

Abstract: An ink feeding method for a printing machine includes a color density measuring step for measuring color density of prints at intervals of time, a variation coefficient computing step for computing a variation coefficient for varying the ink feeding rate based on the color density of prints and a target color density of prints, a color density gradient computing step for computing, based on the color density of prints, a color density gradient representing a rate of variation in the color density of prints occurring with an increase in the number of prints, an expected color density computing step for computing, based on the color density gradient, an expected color density of prints occurring after a predetermined number of prints are made, a determining step for determining whether the expected color density of prints occurring after the predetermined number of prints are made exceeds the target color density of prints, and a variation coefficient correcting step for correcting the variation coefficient whe

Abstract: A method of feeding dampening water includes a density measuring step for measuring densities of first and second detecting patches 101 and 102 printed adjacent each other on printed matter 100 and presenting a difference in density variations after printing with varied feed rates of damping water and ink, a dampening water feeding step for controlling the feed rate of dampening water based on the densities of the first and second detecting patches 101 and 102 measured in the density measuring step, and an ink feeding step for controlling the feed rate of ink based on the densities of the first and second detecting patches measured in the density measuring step, and the feed rate of dampening water.

Abstract: A method of feeding dampening water includes a density measuring step for measuring densities of first and second detecting patches 101 and 102 printed adjacent each other on printed matter 100 and presenting a difference in density variations after printing with varied feed rates of damping water and ink, a dampening water feeding step for controlling the feed rate of dampening water based on the densities of the first and second detecting patches 101 and 102 measured in the density measuring step, and an ink feeding step for controlling the feed rate of ink based on the densities of the first and second detecting patches measured in the density measuring step, and the feed rate of dampening water.

Abstract: An image scanning technique of the present invention shortens the time required for reading images of a plurality of originals set on an original tray. The positions of a lens 18 and a line of CCDs 20 are adjusted, so as to enable a scanning range of the line of CCDs 20 in a primary scanning direction to cover a plurality of originals. A first shooting range Z1 of the line of CCDs 20 covers four trimming areas Tr1,Tr2, Tr5, and Tr6. The procedure of the image scanning technique first reads white reference data of a white reference plate in the first shooting range Z1, then scans the four trimming areas Tr1, Tr2, Tr5, and Tr6 while fixing the shooting range to the first shooting range Z1, and carries out shading correction to correct image data obtained by the scan with the white reference data. This structure requires the process of scanning the white reference plate and updating the white reference data only once for correcting the image data of the plurality of originals.

Abstract: An image scanning technique of the present invention shortens the time required for reading images of a plurality of originals set on an original tray. The positions of a lens 18 and a line of CCDs 20 are adjusted, so as to enable a scanning range of the line of CCDs 20 in a primary scanning direction to cover a plurality of originals. A first shooting range Z1 of the line of CCDs 20 covers four trimming areas Tr1, Tr2, Tr5, and Tr6. The procedure of the image scanning technique first reads white reference data of a white reference plate in the first shooting range Z1, then scans the four trimming areas Tr1, Tr2, Tr5, and Tr6 while fixing the shooting range to the first shooting range Z1, and carries out shading correction to correct image data obtained by the scan with the white reference data. This structure requires the process of scanning the white reference plate and updating the white reference data only once for correcting the image data of the plurality of originals.