JP4723870B2 - Method and apparatus for setting target pixel region for color tone control of printing and picture color tone control method and apparatus of printing press - Google Patents

Description

The present invention relates to a picture color tone control method and apparatus for a printing press that uses a sensor to control color tone by paying attention to a specific pixel region.

Various techniques have been proposed as techniques for controlling the color tone of a picture of a printing press.
For example, in the techniques proposed in Patent Document 1 and Patent Document 2, color tone control is performed in the following procedure.
First, the spectral reflectance of the pattern printed by each color printing unit is measured with a spectrometer. Then, the spectral reflectance (average spectral reflectance of the entire key zone) is calculated for each key zone of the ink key, and the color coordinate value (L * a * b) proposed by the International Illumination Committee for the spectral reflectance of each key zone. *). Test printing is performed by adjusting the ink supply amount of each color, and when a print sheet having a desired color tone (hereinafter referred to as “OK sheet”) is obtained, the color coordinate value of each key zone of the OK sheet is set as the target color coordinate value. To do. Next, the actual printing is started, and the color coordinate value difference (color difference) between the OK sheet and the printing sheet (hereinafter, the printing sheet obtained by the main printing is referred to as the main printing sheet) is calculated for each key zone. The increase / decrease amount of the ink key opening of each printing unit with respect to is calculated, and the opening of each ink key of each printing unit is adjusted by online control so that the color difference becomes zero.

  However, in the techniques disclosed in Patent Documents 1 and 2, a spectrometer is used as a measuring unit, the spectrometer is expensive, and the spectrometer is a measurement target (in this case, a printing press). When the sheet moves at a very high speed, it cannot follow the processing capacity. Further, in the above method, since tone control is started after the OK sheet is printed, a lot of damaged paper is generated between the start-up and the printing of the OK sheet. Further, in the above method, since the image in the key zone of the ink key is averaged over the entire key zone and the color tone control is performed based on the average spectral reflectance, when the image line ratio of the image in the key zone is low, The measurement error of the spectrometer becomes large and the control tends to become unstable. Furthermore, orders from customers may require particularly strict color tone management for specific attention points in the design. If you want to control the color tone for specific attention points in this way, you can use a standard image. Data such as CIP3 [PPF (Print Production Format) data of CIP3 (Cooperation for Integration of Prepress, Press, Postpress) standard] etc. must be obtained from the upstream plate making process as data.

In order to solve these problems, Patent Document 3 proposes a technique for performing color tone control according to the following procedure.
First, a target color mixture halftone density is set for each ink supply unit width when the printed pattern is divided by the ink supply unit width of the ink supply apparatus. The ink supply unit width of the ink supply device is the key width (key zone) of each ink key when the ink supply device is an ink key device, and when the ink supply device is a digital pump device. It is the pump width of each digital pump. A method for setting the target color mixture halftone density will be described later.

  When printing is started and a main printing sheet is obtained, an actual color mixture halftone density for each ink supply unit width of the main printing sheet is measured using an IRGB densitometer. Then, the actual halftone dot area ratio of each ink color corresponding to the actual mixed color halftone density is obtained based on the correspondence relationship between the halftone dot area ratio of each ink color and the mixed color halftone density. As a method for obtaining the actual halftone dot area ratio from the actual mixed color halftone density, a database storing the relationship between the halftone dot area ratio of each ink color and the mixed color halftone density, for example, newspaper printing JapanColor established by the ISO / TC130 National Committee. A database obtained by printing a standard printed matter and actually measured by an IRGB densitometer may be used. More simply, a value approximated by a well-known Neugebauer equation can be used by using the database. Further, based on the correspondence between the halftone dot area ratio and the mixed color halftone density, the target halftone dot area ratio of each ink color corresponding to the target mixed color halftone density is also obtained. The target halftone dot area ratio does not need to be obtained every time as the actual halftone dot area ratio, and may be obtained once as long as the target mixed color halftone density does not change. For example, the target dot area ratio may also be obtained when the target color mixture halftone density is set.

  Next, an actual monochrome halftone density corresponding to the actual halftone dot area ratio is obtained based on a correspondence relationship between a preset halftone dot area ratio and the monochrome halftone density. As a method of obtaining the actual monochrome dot density from the actual dot area ratio, a map or table showing the relationship between the monochrome dot density and the dot area ratio is prepared, and the actual dot area ratio is set in these maps or tables. It may be applied, or more simply, the relationship may be approximated using a well-known Yule-Nielsen equation and used to determine the relationship. Further, based on the correspondence relationship between the halftone dot area ratio and the monochrome halftone density, a target monochrome halftone density corresponding to the target halftone dot area ratio is also obtained. The target monochromatic halftone density need not be obtained every time as in the case of the actual monochromatic halftone density, and may be obtained once as long as the target halftone dot area ratio does not change. For example, the target monochromatic halftone density may also be obtained when the target halftone dot area ratio is set.

  Next, based on the correspondence relationship between the halftone dot area ratio, the monochrome halftone density, and the solid density set in advance, the solid color corresponding to the deviation between the target monochrome halftone density and the actual monochrome halftone density under the target halftone dot area ratio. Obtain the concentration deviation. As a method for calculating the solid density deviation, a map or table showing the above-mentioned body correspondence may be prepared, and the target halftone dot area ratio, the target monochromatic halftone density, and the actual monochromatic halftone density may be applied to these maps and tables. More simply, the relationship may be approximated using a well-known Yule-Nielsen equation and obtained using this equation. Then, the ink supply amount is adjusted for each ink supply unit width based on the obtained solid density deviation, and the ink supply amount for each color is controlled for each ink supply unit width. The adjustment amount of the ink supply amount based on the solid density deviation can be easily obtained using a known API (Auto Preset Inking) function.

According to such a pattern color tone control method, the color tone control can be performed using an IRGB densitometer instead of a spectrometer, so that the cost for measuring means can be reduced and the high-speed printing machine such as a newspaper rotary press can be used. It becomes possible to respond sufficiently.
Further, as a method for setting a target color mixture halftone density when kcmy halftone dot area ratio data (for example, image data for plate making) of a print target pattern can be acquired from the outside (for example, a print request source), the following points are provided. Proposed.

  First, with respect to the acquired image data (kcmy halftone dot area ratio data), a pixel of interest corresponding to each ink color for each ink supply unit width among pixels constituting the pattern to be printed (a pixel of interest is a single pixel). (It may be a plurality of continuous pixels), and the halftone dot area ratio of the target pixel is converted into the mixed color halftone density based on the correspondence between the halftone dot area ratio and the mixed color halftone density. Then, the mixed color halftone density of the target pixel is set as the target mixed color halftone density, and the actual mixed color halftone density of the set target pixel is measured.

  According to this, since color development can be estimated on a pixel-by-pixel basis, such as using the JapanColor database, color tone control can be performed for a specific point of interest (attention pixel) of a pattern immediately after printing starts without waiting for an OK sheet to be printed. Can be performed. The kcmy halftone dot area ratio data may be bitmap data of a pattern to be printed (for example, 1-bit-Tiff plate-making data), or may be obtained by converting bitmap data into low resolution data equivalent to CIP3 data. Good.

Note that the point of interest can be set by displaying an image of a printed pattern on a display device such as a touch panel using bitmap data, and by the operator arbitrarily specifying the point of interest, or by using the most density sensitivity for each ink color. A method has been proposed in which a pixel having a high autocorrelation with respect to a halftone dot area ratio of each pixel is calculated and automatically extracted and set as a pixel of interest for each ink color. In addition, as a specific method of setting the target pixel, an autocorrelation sensitivity H is introduced, a pixel having the highest autocorrelation sensitivity H is set as a pixel having the highest autocorrelation, and this pixel is set as the target pixel. Yes. For example, the autocorrelation sensitivity Hc of cyan can be expressed by “Hc = c ² / (c + m + y + k)” using each pixel area ratio data (c, m, y, k). The pixel with the highest value is the cyan attention point.

In this way, for each ink color, the pixel having the largest autocorrelation with respect to the dot area ratio of each pixel is calculated and extracted, and this is set as the target pixel. By calculating the halftone density and performing feedback control of the ink supply amount so that the actual single color halftone density approaches the target single color halftone density, more stable color tone control can be performed.
JP 2001-18364 A JP 2001-47605 A JP 2004-106523 A

  By the way, in the above technique, when the target pixel is automatically set, the pixel having the highest autocorrelation (one pixel or a plurality of continuous pixels) is set as the target pixel. The basic unit of pixels to be printed is the pixel unit of plate making data, but the IRGB densitometer, which is a sensor for measuring the actual mixed color halftone density, reduces the amount of reflected light per unit time as the printing speed increases. The measurement accuracy of the densitometer is greatly reduced as the measurement area is affected.

  Therefore, it is necessary to set the pixel of interest using the minimum unit of resolution of the densitometer as a basic unit (this is called a sensor pixel unit or one block). In this case, a collection of a large number of pixels of plate making data corresponds to one pixel (one block) in sensor pixel units. From such a point of view, for example, as shown in FIG. 13 with the symbols C, M, Y, and K, blocks are set in the plate making surface 50 obtained from the plate making data (the actual blocks are so much). It is conceivable that the pixel of interest is set for each block.

  On the other hand, in the technique of Patent Document 3, a pixel having the highest autocorrelation sensitivity H is set as a pixel of interest as a pixel having high density sensitivity and a characteristic that the edge portion of the image is difficult to be included. Sensitivity H includes two conditions: high autocorrelation and low standard deviation. For this reason, when setting a pixel of interest in block units, only a small amount of ink of a certain color may be printed while a majority of the block is blank paper. It may be the block with the highest autocorrelation sensitivity of the ink color.

If the block with the highest autocorrelation sensitivity selected in this way is set as the pixel of interest, the density of the corresponding ink color that is printed only slightly in the block is detected and the tone control is performed, and the density detection sensitivity is increased. The accuracy of the color tone control may decrease due to the decrease.
Therefore, we would like to set the target pixel appropriately so that the color tone control can be carried out more accurately.For example, in the case of newspaper printing, it is necessary to complete the process from paper editing to printing completion in a short time. Not only is the pixel setting appropriate, it must be done efficiently in a short time.

  The present invention has been devised in view of the above-described problems, and can improve the accuracy of color tone control by appropriately setting a target location (target pixel) for control in a short time and efficiently. It is an object of the present invention to provide a method and apparatus for setting a target pixel area for color tone control of printing and a method and apparatus for controlling a picture color tone of a printing press.

In order to achieve the above-described target, the target pixel region setting method for color tone control according to the present invention uses the target pixel region for each ink color to be used for feedback control of the color tone of printing by paying attention to a specific pixel region in a printed pattern. A method of setting, a pixel-of-interest area information writing step of writing information on the pixel-of-interest area corresponding to the plate-making data into the job ticket data when creating plate-making data and printing job ticket data; in carrying out the printing based on the job ticket data, and a noticed pixel region setting step for setting the noticed pixel region into printing picture based on information about the target pixel region written with the above, said pixel of interest There is little information about the area among the solid area, the net area, and the flat area. It is characterized in that also selection information to select one of the any two regions (claim 1). Note that the pixel-of-interest area information writing step is performed, for example, by a person in charge of paper configuration such as a paper designer who is in charge of paper configuration, and the pixel-of-interest region setting step is performed by a print operator or the like.

For example, the printing picture, generally there is a solid area and halftone area of the various halftone dot area ratio, but the paper structure personnel, etc., in particular the control with an emphasis on the color tone of the solid area of the printing picture If it is desired to write information indicating that the solid area is the target pixel area in the job ticket data, and control the emphasis on the color tone of the print area, in particular, the net area is set to the job ticket data. It is only necessary to write information to that effect. In addition, since solid areas and flat mesh areas tend to have uneven color tone, if you want to eliminate such uneven color tones in solid areas or flat mesh areas, the person in charge of the page configuration, etc., should pay attention to the job ticket data in the target pixel area. Information for setting a solid area or a flat net area may be written.

Further, the upper Kitaira network region is preferably image differential value of the halftone dot area ratio of the printing picture is a region below a preset reference value (claim 2). In this case, the image differential value of the halftone dot area ratio is a difference value from adjacent pixels, and the preset reference value for the image differential value of the halftone dot area ratio is, for example, 1%. Can do.
The solid area is an area where the value of the halftone dot area ratio of the printed pattern is equal to or greater than a preset reference value, and the halftone area of the printed pattern is less than the reference value The region is preferable (claim 3). In this case, a preset reference value for the value of the halftone dot area ratio can be set to 70%, for example.

Further, in the target pixel region setting step, it can be set manually or automatically the noticed pixel region based on the information on the pixel of interest areas (Claim 4). In the case of manual, it can be set by, for example, a printing operator, and in the case of automatic, it can be set by using, for example, a computer.
It is preferable that the noticed pixel region to be used for color tone control of the printing of the minus edge portion of the above set noticed pixel region by a predetermined sensor pixels (claim 5).

The target pixel region setting step performed based on the information on the target pixel region is set as a first target pixel region setting step, and, separately from the first target pixel region setting step , halftone dot area ratio data of plate making data is used. Based on this, a region having a high autocorrelation for each ink color is selected for each sensor pixel of the sensor for measuring the amount of reflected light, and the edge portion of the corresponding ink color is removed from the selected region by a predetermined sensor pixel. the area, preferably further comprising a second noticed pixel region setting step of setting as the target pixel area of the pertaining ink color (claim 6).

The target pixel region setting step performed based on the information regarding the target pixel region is a first target pixel region setting step, and the halftone dot area ratio of the plate making data is separated from the first target pixel region setting step. A step of setting the pixel region of interest based on data , wherein a region having a high autocorrelation for each ink color is selected for each sensor pixel of a sensor for measuring the amount of reflected light , and the corresponding ink is selected from the selected region; If the target pixel area exists even if the edge portion of the color is removed by the predetermined sensor pixel, the area obtained by removing the edge portion by the predetermined sensor pixel from the selected region is used as the corresponding ink color. In the case where the pixel region of interest disappears when the edge portion is removed by a predetermined number of sensor pixels, the selected region is set as the pixel region of interest. The region above the autocorrelation is high without excluding the edge portion, that further includes a second noticed pixel region setting step of setting as the target pixel area of the pertaining ink color preferred in (Claim 7 ).

In the second pixel-of-interest region setting step, it is preferable that when the corresponding ink color edge portion is removed from the selected region in the sensor pixel unit, only one pixel is removed in the sensor pixel unit. 8).
Et al is, the noticed pixel region setting step of performing on the basis of the information on the pixel of interest area are first noticed pixel region setting step, the above first noticed pixel region setting step separately, based on the plate making data A region having a high autocorrelation for each ink color is selected for each sensor pixel of the sensor for measuring the amount of reflected light, and the region having a high autocorrelation is selected from the selected region so as to include an edge portion of the corresponding ink color. an area inflated to the outside, preferably further comprising a second noticed pixel region setting step of setting as the target pixel regions (claim 9).
In addition, the region having a high autocorrelation in the second pixel-of-interest region setting step is a group of all pixels having an autocorrelation higher than a preset condition for each ink color. pixel region setting step, is preferably configured as a noticed pixel region automatically setting step of automatically extracting the pixel group by using a computer (claim 10).

The sum area of the first target pixel area set by the first target pixel area setting step and the second target pixel area set by the second target pixel area setting step is set as the target pixel area. (Claim 11 ).
The printing press picture color tone controlling method of the present invention (Claim 12), the target pixel area set by using the color tone control noticed pixel region setting method according to any one of claims 1 to 11 A pattern color tone control method for a printing press that feedback-controls the color tone of printing with attention, and is obtained by printing using a target color mixture halftone density setting step for setting a target color mixture halftone density for the pixel region of interest and the sensor. was the actual color mixture halftone density measurement step of measuring an actual color mixture halftone density regarding the noticed pixel region for each ink color for each Yi Nki supplying unit widths of the print sheet, the halftone dot area ratios and color mixture halftone densities set in advance Based on the correspondence relationship, the target halftone dot area ratio calculating step for obtaining the target halftone dot area ratio of each ink color corresponding to the target mixed color halftone density, and based on the correspondence relationship between the halftone dot area ratio and the mixed color halftone density, Above Based on the actual halftone dot area ratio calculating step for obtaining the actual halftone dot area ratio of each ink color corresponding to the color halftone density, and the correspondence relationship between the predetermined halftone dot area ratio and the single color halftone density, the above target halftone dot area ratio Based on the correspondence relationship between the halftone dot area ratio and the monochromatic halftone density, the actual monochromatic halftone density corresponding to the actual halftone dot area ratio is calculated based on the target monochromatic halftone density calculating step for obtaining the target monochromatic halftone density corresponding to The target monochromatic halftone density based on the target halftone dot area ratio for the target pixel region based on a monochrome halftone density calculating step and a correspondence relationship between a predetermined halftone dot area ratio, a monochromatic halftone density, and a solid density. A solid density deviation calculating step for obtaining a solid density deviation corresponding to a deviation between the actual monochrome color halftone density and an ink supply amount adjusting step for adjusting the ink supply amount for each ink supply unit width based on the solid density deviation. In preparation It is characterized by being.

Further, the target pixel area setting method for color tone control according to any one of claims 6 to 11 is used, and the target mixed color halftone density setting step, the actual mixed color halftone density measuring step, and the target halftone dot area ratio calculating step are performed. , An actual halftone dot area ratio calculating step, a target monochromatic halftone density calculating step, an actual monochromatic halftone density calculating step, and a solid density deviation calculating step are set to the first target pixel area set by the first target pixel area setting step. And the second target pixel region set by the second target pixel region setting step, and the ink supply amount adjusting step performs the ink based on the two solid density deviations obtained from them. it is preferable to adjust the ink supplying amount for each supply unit width (claim 13).

In the ink supply amount adjustment step, the solid density deviation obtained for the first pixel of interest and the solid density deviation obtained for the second pixel of interest are set according to a preset weight. and weighted average Te, it is preferable to adjust the ink supplying amount for each of the ink supplying unit widths based on the weighted average solid density deviation (claim 14).
Tone control noticed pixel region setting apparatus of the printing of the present invention (Claim 15), the noticed pixel region for each ink color to be used for feedback control of the tone of interest to print a particular pixel region in the printing picture an apparatus for setting, controlling and writing means for writing information on the noticed pixel region corresponding to the plate making data to the plate making data and the print job ticket data, the printing based on the plate making data and the job ticket data And an arithmetic unit that automatically sets the target pixel area based on the information on the target pixel area, and the information on the target pixel area includes a solid area, a net area, and a flat net area as the target pixel area. It is the selection information which selects one from at least any two areas.

Upper Kitaira network region is preferably image differential value of the halftone dot area ratio of the printing picture is a region below a preset reference value (claim 16).

The solid area is an area where the value of the halftone dot area ratio of the printed pattern is equal to or greater than a preset reference value, and the halftone area of the printed pattern is less than the reference value The region is preferable (claim 17 ).
The arithmetic unit is preferably in a noticed pixel region to be used for color tone control of the printing of the minus edge portion of the above set noticed pixel region by a predetermined sensor pixels (claim 18).

The arithmetic unit includes a first target pixel region setting unit that sets a target pixel region based on the information about the target pixel region and a first target pixel region setting unit, based on plate making data. A region with a high autocorrelation for each ink color is selected for each sensor pixel of the sensor that measures the amount of reflected light, and a region obtained by removing the edge portion of the corresponding ink color from the selected region by a predetermined sensor pixel is selected. it is preferable that includes the second noticed pixel region setting means for setting as the target pixel (claim 19).
The upper SL computing device, a first noticed pixel region setting means for setting a noticed pixel region based on the information on the pixel of interest areas, apart from the first noticed pixel region setting means, based on the plate making data A region having a high autocorrelation for each ink color is selected for each sensor pixel of the sensor for measuring the amount of reflected light, and the region having a high autocorrelation is included from the selected region to include an edge portion of the corresponding ink color. of an area inflated to the outside, it is preferable that includes the second noticed pixel region setting means for setting as the target pixel regions (claim 20).

In the arithmetic device, a sum area of the first target pixel region set by the first target pixel region setting unit and the second target pixel region set by the second target pixel region setting unit is calculated. it is preferable to set the noticed pixel region (claim 21).
A picture color tone control device for a printing press according to the present invention (Claim 22 ) includes a target pixel region setting device for color tone control of printing according to any one of Claims 15 to 21 , and a final printing obtained by printing. operations and sensor disposed on a sheet traveling line of the target color mixture halftone density setting means for setting a target color mixture halftone density regarding the noticed pixel region of each divided Lee Nki supplying unit width in the print width direction, the sensor Then, based on the correspondence relationship between the mixed color halftone density measuring means for measuring the actual mixed color halftone density for each ink supply unit width of the main printing sheet and the preset halftone dot area ratio and the mixed color halftone density, the target mixed color halftone network A target halftone dot area ratio calculating means for obtaining a target halftone dot area ratio of each ink color corresponding to the density, and each corresponding to the actual mixed color halftone density based on the correspondence relationship between the halftone dot area ratio and the mixed color halftone density. Find the actual dot area ratio of ink color An actual halftone dot area ratio calculating means, a target monochrome halftone density calculating means for obtaining a target monochrome halftone density corresponding to the target halftone dot area ratio based on a correspondence relationship between a preset halftone dot area ratio and a monochrome halftone density; Based on the correspondence relationship between the halftone dot area ratio and the monochromatic halftone density, an actual monochromatic halftone density calculating means for obtaining an actual monochromatic halftone density corresponding to the actual halftone dot area ratio, a preset halftone dot area ratio and a monochromatic halftone dot Solid density deviation calculating means for obtaining a solid density deviation corresponding to a deviation between the target single color halftone density and the actual single color halftone density under the target halftone dot area ratio based on a correspondence relationship between density and solid density; And an ink supply amount adjusting means for adjusting the ink supply amount for each ink supply unit width by feedback control based on the solid density deviation.

The target color mixture halftone density is set as the data that can be acquired from the plate making data , for example, by using the kcmy halftone dot area ratio data of the print target image such as image data for plate making, the pixels constituting the print target picture The target pixel corresponding to each ink color is set for each ink supply unit width, and the halftone dot area ratio of the target pixel is determined based on the relationship between the preset halftone dot area ratio and the mixed color halftone density. Can be converted to Then, the mixed color halftone density of the target pixel is set as the target mixed color halftone density, and the actual mixed color halftone density of the set target pixel is measured. According to this, since the color development can be estimated in units of pixels by using the JapanColor database or the like, it is possible to perform printing appropriately while performing color tone control on the pixel region of interest set with the pattern immediately after the start of printing.

As the above kcmy halftone dot area ratio data, bitmap data of a pattern to be printed (for example, data for 1-bit-Tiff plate making) or CIP4 equivalent to 50.8 dpi (International Cooperation for Integration of Processes in Prepress, Press, and Postpress) standard JDF (Job Definition Format) data, or the same resolution-converted data (1200 dpi or 2400 dpi 1-bit-Tiff data converted to 50 dpi 8-bit-Tiff), and bitmap data can be converted to JDF. Data converted into low-resolution data equivalent to data may be used.

Further, based on the correspondence between the preset color mixture halftone density and the color coordinate value, the actual color coordinate value corresponding to the actual color mixture halftone density of the target pixel measured by the sensor and the target color coordinate corresponding to the target color mixture halftone density The color difference between the actual color coordinate value and the target color coordinate value may be obtained by obtaining the value, and the actual color coordinate value and / or the color difference may be displayed on the display device. According to this, it is possible to intuitively understand how much the color matches the operator.

According to the method for setting a pixel area of interest for printing color tone control (Claim 1) and the apparatus (Claim 15 ) of the present invention, for example, a person in charge of page configuration, such as a designer of a page to print, makes plate making data and printing When creating the job ticket data, information related to the target pixel area corresponding to the plate making data is written in the job ticket data, and at the time of printing, the print operator adds the target pixel in the print pattern based on the information regarding the written target pixel area. The region may be set, and the target pixel region can be set appropriately in a short time. For this reason, even when it is necessary to complete a short period of time from paper editing to printing completion, such as newspaper printing, the target pixel area can be appropriately set, and printing is performed based on the target pixel area. Can be accurately controlled.

In addition, as the information on the target pixel area, for example, selection information for selecting one of the areas of the solid area, the net area, and the flat net area is selected as the target pixel area. Thus, it is only necessary to select and operate one of the regions, and the burden on the printing operator for setting the pixel region of interest is reduced (claims 1 and 15 ).
Further, the upper Kitaira network region, has the above printing picture images differentiation dot percent (the difference between the adjacent pixel) value previously set reference value (for example, 1%) or less in the region (claim 2 , 16) and, on the Symbol solid area, the solid area of the dot percent of the printing picture value preset reference value (e.g., 70%) as a more regions, the net area of the printing picture By setting the halftone dot area ratio to a region less than the reference value (Claims 3 and 17 ), it is possible to easily automatically select each of the solid region, the halftone region, and the flat halftone region.

In the target pixel region setting step, the calculation device automatically sets the target pixel region based on the information on the target pixel region (claim 4), so that the print operator for setting the target pixel region The burden is further reduced.
Further, by setting a region obtained by removing the edge portion of the target pixel region by a predetermined number of sensor pixels as a target pixel region used for printing tone control (claims 5 to 7, 18 , 19 ), It is possible to prevent other areas including blank areas from entering, and density detection is possible even when the target image position and the current image position deviate when the printing speed is increased or when paster (automatic paper splicing) is performed. A decrease in sensitivity can be prevented, and a decrease in the accuracy of color tone control can be suppressed.

Further, apart from the target pixel region setting step (first target pixel region setting step) performed based on the information regarding the target pixel region, the autocorrelation is high for each ink color based on the dot area ratio data of the plate making data. A second target pixel region setting step is provided in which a region is selected in units of sensor pixels, and a region obtained by removing a corresponding ink color edge from the selected region by a predetermined sensor pixel is set as the target pixel. you by (claim 6), but a different measure than the measure of the target point selection, such as the staff in charge of creation paper structure (region having a high autocorrelation), can be set noticed pixel region at the time of printing An operator or the like can respond to a print quality request in a different position from the person in charge of creating the paper configuration.

In addition, if the target pixel disappears when the edge portion is removed by a predetermined number of sensor pixels, the region having the high autocorrelation is excluded from the selected region without removing the edge portion. By further including a second target pixel setting step for setting the target pixel of the ink color (claim 7 ), a scale (autocorrelation) different from the scale for selecting the target point of the person in charge of creating the page configuration, etc. The target pixel region in the region where the target pixel is high) is also applied to a few selected regions (regions with high autocorrelation) where the target pixel disappears by removing the edge portion by a predetermined number of pixels. it can.

Further, according to the design color tone control method (claim 12 ) and apparatus (claim 22 ) of the printing press according to the present invention, the tone control can be performed using a sensor that measures the amount of reflected light instead of the spectrometer. It can reduce the cost of measuring means due to misregistration, and can sufficiently support high-speed printing presses such as a newspaper rotary press, and feedback control of the color tone of printing based on an appropriately set pixel area of interest. Therefore, it is possible to appropriately control the color tone.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a newspaper offset rotary press according to an embodiment of the present invention. The newspaper web offset press of this embodiment is a multi-color printing duplex printing machine, and ink colors [black (k), indigo (c), red (m), yellow (y )] Is provided for each printing unit 2a, 2b, 2c, 2d. In the present embodiment, the printing units 2 a, 2 b, 2 c, and 2 d are provided with an ink key type ink supply device including an ink key 7 and an ink source roller 6. In this type of ink supply apparatus, the ink supply amount can be adjusted by the amount of gap between the ink key 7 and the ink base roller 6 (hereinafter, this gap amount is referred to as the ink key opening). A plurality of ink keys 7 are juxtaposed in the printing width direction, and the ink supply amount can be adjusted in the width unit of the ink key 7 (hereinafter, the ink supply unit width by the ink key 7 is referred to as a key zone). The ink whose supply amount is adjusted by the ink key 7 is moderately kneaded in the ink roller group 5, is supplied to the plate surface of the plate cylinder 4 after forming a thin film, and the ink adhering to the plate surface passes through the blanket cylinder 3. As shown in FIG. Although not shown in FIG. 1, the newspaper offset rotary press of this embodiment is a double-sided printing, and therefore a pair of printing units 2 a, 2 b, 2 c, and 2 d is provided so as to sandwich the conveyance path of the printing sheet 8. Blanket cylinders 3 and 3 are provided, and a plate cylinder 4 and an ink supply device are provided for each blanket cylinder 3.

The newspaper offset rotary press of this embodiment includes a line sensor type IRGB densitometer (sensor) 1 further downstream of the most downstream printing unit 2d. The line sensor type IRGB densitometer 1 reflects I (infrared light), R (red), G (green), and B (blue) reflection densities (mixed-color network) in the form of a line in the print width direction of the pattern color on the printing sheet 8. It is possible to measure the reflection density of the entire print sheet 8 or to measure the reflection density at an arbitrary position. Since the newspaper offset rotary press of this embodiment is a double-sided printing, the line sensor type IRGB densitometer 1 is arranged on both the front and back sides so as to sandwich the conveyance path of the printing sheet 8, and the reflection density on both the front and back sides can be measured. .

  The reflection density measured by the line sensor type IRGB densitometer 1 is transmitted to an arithmetic unit (computer) 10. The computing device 10 is a device that computes ink supply amount control data, performs computation based on the reflection density measured by the line sensor type IRGB densitometer 1, and matches the pattern color of the printing sheet 8 with the target color. The opening of the ink key 7 is calculated. Here, FIG. 2 is a functional block diagram focusing on the color tone control function of the arithmetic unit 10 as well as the schematic configuration of the pattern color tone control device for the newspaper offset rotary press according to one embodiment of the present invention. .

  The arithmetic unit 10 is composed of a DSP (digital signal processor) 11 and a PC (personal computer) 12 that are installed apart from the printing press. The PC 12 includes a color conversion unit 14, an ink supply amount calculation unit 15, an online system. Functions as the control unit 16 and the key opening limiter calculation unit 17 are assigned. The line sensor type IRGB densitometer 1 is connected to the input side of the arithmetic device 10, and the control device 20 with a built-in printing press is connected to the output side. The control device 20 functions as an ink supply amount adjusting means for adjusting the ink supply amount for each key zone of the ink key 7, and controls an opening / closing device (not shown) that opens and closes the ink key 7, and each printing unit 2a, The key opening can be adjusted independently for each of the ink keys 7 of 2b, 2c, and 2d.

  In addition, a display device (print area monitor) for displaying a printed pattern on the paper surface is connected to the arithmetic device 10, and the print area monitor 40 also has a function as a touch panel. The touch panel 40 displays the plate-making data obtained by converting the printing surface of the printing sheet 8 into an image, or the printing surface of the printing sheet 8 imaged by the line sensor type IRGB densitometer 1. You can select the area with your finger.

Prior to color tone control, a target pixel region (also referred to as a target point) is set, and the target pixel region setting method and apparatus for color tone control of printing according to the present invention are applied to the setting of the target pixel region. Has been.
Here, a target pixel region setting method and apparatus for controlling color tone of printing according to the present embodiment will be described. As shown in FIG. 6, the processing steps for setting the target pixel area include processing steps for the paper surface creation part (steps A10 to A30) and processing steps for the printing part (steps A40 to A80). In the case of a national newspaper, the paper preparation part is processed mainly at the base station side, and the printing part is processed mainly at the printing factory in each region.

  That is, for example, in the paper surface creation part on the base station side, the person in charge of the paper surface, such as the designer of the paper surface to be printed, configures the paper surface to be printed (step A10), and creates plate making data based on this (step A20). Further, information relating to the pixel region of interest is written in the job ticket data relating to this printing (step A30). Job ticket data corresponds to a process document that describes the attributes and procedures of printing process management (Processes), plate making (Prepress), printing (Press), and post-processing (Postpress). Although it is created, information on the target pixel region is added to a part of the job ticket data.

  The data format of the job ticket is not limited at all. For example, the JDF (Job Definition Format) of the CIP4 (International Cooperation for Integration of Processes in Prepress, Press, and Postpress) standard uses the XML language. Therefore, it is possible to incorporate not only machine control instructions but also more detailed information such as information to be reflected in business management, and it is easy to write information on the target pixel area. Therefore, it is also preferable to employ a versatile job ticket data format such as CIP4 standard JDF data.

Here, “information on the target pixel region” will be described. When the “target pixel area” is set, the ink supply is controlled so that each ink in the pixel area has a target density. Therefore, it is only necessary to set a portion of the target print pattern for which color tone control is to be performed with high accuracy as the “target pixel region”.
For example, the printing picture, if attention is paid to the dot percent, Classification and base data area, in the network area. Further, paying attention to changes in the halftone dot area ratios can be classified into the above dot percentage uniform tint region, and other realm. In the present embodiment, by selecting what you want to emphasize one of the solid area and the Amiryo region and Hiraamiryo region to the target pixel region, thereby performing the color tone control.

  Select a solid area when emphasizing the heavy part of the design, select a mesh area when emphasizing the light part of the design, and select a flat area when emphasizing the net region part with a uniform pattern. . The flat halftone area that should originally have a uniform color tone has uneven color due to a slight difference in the amount of ink. Therefore, in order to prevent or suppress these, the flat halftone area may be selected. In addition, when it is desired to match a solid color or a halftone (halftone) color with high accuracy, a solid area or a halftone area may be selected. It should be noted that if the control is performed by excluding a highlight portion (a portion having a very small halftone dot area ratio) in the halftone area, halftone can be easily obtained with higher accuracy, so the upper limit of the halftone dot area ratio (for example, 70 percent or 80%) and a lower limit (for example, 20%) may be provided to define the net region.

In this case, the decision as to which should be emphasized is appropriate for the person responsible for the page composition, such as a page designer who creates the sheet based on the request from the customer, and the person responsible for the page composition, for example, the solid area and the network area Alternatively, an area desired by the client to be used as the target pixel area is added to a part of the job ticket data.
On the other hand, for example, in the printing part on the printing factory side, the job ticket data (step A40) sent from the paper surface creation part and the plate making data are acquired (step A50), and the color matching emphasis specified by the designer in the plate making part is emphasized. If the coordinates for the plate making data are not written in the job ticket data, after the determination in step A55, the guidance in the job ticket data based on the plate making data (that is, information on the target pixel region for color tone control) is used. Correspondingly, a pixel region of interest for which a color is to be matched is selected (step A60), and further, an integration control point (a pixel of interest region) corresponding to a preset setting criterion is automatically extracted based on the plate making data (step A70). . In addition, if the coordinates for the plate making data that emphasizes color matching specified by the designer in the plate making part are written in the job ticket data, the coordinates written in the job ticket data are preferentially selected, and the position is noted. A pixel is selected (step A90).

  As described above, the target pixel area is set according to the guidance in the job ticket data (step A60: first target pixel area setting step for setting the first target pixel area), and a preset setting. The target pixel area is set in two systems, corresponding to the reference (step A70: second target pixel area setting step for setting the second target pixel area), and the first and second attentions are set. The final pixel region of interest is set by combining the pixel regions. When the first and second target pixel regions are combined, the first tone pixel region and the second target pixel region are weighted and averaged according to the set weight A, and the tone control is performed. It is supposed to be.

  The setting of the first target pixel area according to the guidance in the job ticket data in step A60 will be further described. At the print preparation stage, as shown in FIG. 7B, an automatic target point candidate selection screen is printed. It is displayed on the area monitor 40 or other monitor. On this selection screen, manual attention point control (manually setting the target pixel region and controlling the color tone), solid color emphasis [automatically setting the target pixel region as a solid region and controlling the color tone, FIG. ) Reference] and emphasis on the color of the mesh [automatically set the pixel area of interest to the mesh area and control the color tone, see FIG. 7C] and emphasis on the color of the flat mesh (solid area of the pixel area of interest Are automatically set to control the color tone, see FIG. 8 (b)], and each check column is selected according to the guidance in the job ticket data. Yes. At this time, it may be checked manually by an operator or automatically by the PC 12. Here, in the initial state, the manual attention point control is checked, and when there is no guidance in the job ticket data, the attention pixel area can be manually set by the operator. Furthermore, in the present embodiment, coordinates for plate making data emphasizing color matching specified by the designer in the plate making part can be written in job ticket data, and coordinates for plate making data emphasizing color matching are written in job ticket data. If so, the position is preferentially selected as the target pixel as described above.

  Also, an automatic attention point designation halftone dot area ratio (solid dot area ratio for solid area and halftone area) X and flat halftone weighted pixel differentiation threshold [a halftone dot area ratio for flat halftone area (including solid area)] The differential value] Y can be changed. Here, the default value of the automatic attention point designation halftone dot area ratio X is 70%, and the default value of the flat halftone weighted pixel differentiation threshold Y is 1% / n pixels [the amount of change in the halftone dot area ratio per unit pixel]. (Percentage)]. Of course, these default values are not limited to such values.

  Then, when the solid area or halftone area is checked (selected) and the automatic attention point designation halftone dot area ratio X is appropriately changed, first, as shown in FIG. Extraction of the halftone dot area ratio of the pixel) (step B10), the halftone dot area ratio is compared with the automatic target point designated halftone dot area ratio X, and the halftone dot area ratio is X for each pixel of each ink. While determining whether the above-mentioned solid area or a halftone area less than X (step B20), if a solid color is important (solid area designation), the corresponding pixel is selected (extracted) as an attention point (attention pixel), and the color of the mesh If emphasis is given (designation of a halftone area), the corresponding pixel is selected (extracted) as a target point (target pixel), and this is performed on the entire area of the printed pattern to select the target pixel area (step B30). As a result, depending on whether or not the first target pixel region (target integration point) exists (step B40), if the first target pixel region (target integration point) exists, the first target pixel region And a second target pixel area to be described later are combined to set the target pixel area, and based on this, the color tone is controlled (step B50: hybrid control), and the first target pixel area (target integration point) exists. If not, the color tone is controlled based on the second target pixel region (step B60: normal integration control).

  When the flat halftone area is checked (selected) and the flat halftone weighted pixel differentiation threshold Y is appropriately changed, as shown in FIG. 8A, first, an integration point is extracted from the plate-making data (halftone dot of each pixel). (Area ratio extraction) is performed (step C10), and then the halftone dot area ratio of each pixel is differentiated (halftone dot area ratio image differentiation) at the halftone dot position (step C20). If the halftone dot area ratio changes between adjacent pixels, the value of the halftone dot area ratio image derivative is calculated according to the amount of change, but in a flat halftone or solid area, halftone dots are calculated between adjacent pixels. Since the area ratio hardly changes, the value of the halftone dot area ratio image derivative is 0 or substantially 0 (see FIG. 8B). Thus, the calculated halftone dot area ratio image differential value (differential pixel) is compared with the flat halftone weighted pixel differential threshold Y, and if the halftone dot area ratio image differential value (differential pixel) is very small, that pixel is selected as the target pixel. (Step C30). Then, this is performed on the entire area of the printed pattern, and the target pixel area is selected. As a result, depending on whether or not the first target pixel region (target integration point) exists (step C40), if the first target pixel region (target integration point) exists, the first target pixel region And a second target pixel region to be described later are combined to set the target pixel region, and based on this, the color tone is controlled (step C50: hybrid control), and the first target pixel region (target integration point) exists. If not, the color tone is controlled based on the second target pixel region (step C60: normal integration control).

  Since the first target pixel area set in this way is set based on the plate making data, it is set with extremely high accuracy. However, the outer edge of the first target pixel area is Focusing on the fact that there is a possibility of being adjacent to a blank area or other area (such as a net area adjacent to a solid area or a net area adjacent to a flat net area) in which neither color is printed, for example, FIG. As shown by broken lines in (a) to (d) of FIG. 5, a region (shaded portion) obtained by removing the edge portion indicated by diagonal lines from the first target pixel region is set as the first target pixel region. ing. Here, as shown in the enlarged view of FIG. 4, a portion (shaded portion) excluding only one pixel (shaded portion) in the sensor pixel unit of the edge portion is set as the first target pixel region. ing.

Next, the setting of the second target pixel area will be described.
The setting of the second target pixel area is performed through the DSP 11 of the arithmetic unit 10, and the DSP 11 is provided with a function (second target pixel area automatic setting means) for automatically setting the second target pixel area.
That is, the plate making data is input to the computing device 10 in advance, and the DSP 11 of the computing device 10 uses the kcmy halftone dot area ratio data obtained based on this plate making data to print the printed pattern with the ink feeding unit width of the ink feeding device. For each ink supply unit width when divided, a region having a high autocorrelation is selected for each ink color, and a region obtained by removing the edge portion of the corresponding ink color from the selected region by a predetermined number of pixels is selected. Automatically set for each ink color as a target pixel area which is a reference area at the time of control corresponding to the color (this function corresponds to a target pixel area automatic setting means which is one of the second target pixel area setting means) ) Here, the ink supply unit width of the ink supply device is the key width (key zone) of each ink key when the ink supply device is an ink key device, and when the ink supply device is a digital pump device. Is the pump width of each digital pump.

The plate-making data is given as bitmap data. In setting the second target pixel area, the bitmap data is converted into low-resolution data equivalent to CDF4 standard JDF data according to the format of the printing press. In addition, the following processing is performed in units of pixels of the sensor.
That is, the region where the autocorrelation is high for each ink color is specifically a region where the autocorrelation sensitivity H is equal to or higher than a predetermined value, and is defined as a pixel unit region of the sensor (IRGB densitometer) 1. . The pixel unit of the sensor is a minimum unit of resolution of the sensor (IRGB densitometer) 1. Specifically, a collection of a large number of pixels for plate making data corresponds to one pixel (one block) in sensor pixel units. For example, if the resolution data is a low resolution of about 50.8 dpi as in CIP3 and the resolution of the sensor 1 block is 2.54 dpi, the area for 20 pixels in the plate making data and 20 pixels in the width (in pixel units of the plate making data). Thus, 20 × 20 = 400 pixels) is one pixel unit of the sensor pixel unit.

The autocorrelation sensitivity H, for example, the autocorrelation sensitivity Hc of cyan, using pixel area ratio data (c, m, y, k ) and can be represented by ^{"Hc = c n / (c} + m + y + k)", this When the autocorrelation sensitivity Hc is compared with a reference autocorrelation sensitivity value (predetermined value) H ₀ set in advance and the autocorrelation sensitivity Hc is equal to or higher than the reference autocorrelation sensitivity value H ₀ , Become.
Similarly, the other color inks, calculates the value of the autocorrelation sensitivity H, for preset reference autocorrelation sensitivity value respectively (predetermined value) H ₀ Comparison.

The reference autocorrelation sensitivity value H ₀ can be set by an operator's input operation. Therefore, to set a higher reference autocorrelation sensitivity value H _0, by setting the target pixel region autocorrelation Search in fairly high region, the target pixel region decreases but the point strong pertaining ink tone or to raise accuracy of up to tone controlling the concentration detection sensitivity from the reference autocorrelation sensitivity value H ₀ is set to low, by setting the noticed pixel region including even a region autocorrelation is not very high, Although the density detection sensitivity is lowered, it is possible to increase the accuracy of the color tone control by expanding the target pixel region. Of course, a recommended value of the reference autocorrelation sensitivity value H ₀ (for example, the autocorrelation average value of the entire picture) is input in advance, and an operator who is not accustomed can use this recommended value. In principle, the reference autocorrelation sensitivity value H ₀ is a common value for each ink color, but it is also conceivable to change the reference autocorrelation sensitivity value H ₀ depending on the ink color.

  Thus, when a region having a high autocorrelation is selected for each ink color, for example, as shown in FIGS. 3A to 3D, the autocorrelation is high for each ink color in the plate-making surface 50. A region is obtained. If such a region with high autocorrelation is set as a target pixel region as it is, it includes the case where only a small amount of ink of a certain color is printed mostly on white paper as described above. Therefore, the density detection sensitivity is lowered and the accuracy of color tone control is lowered. In particular, if the target image position and the current image position are misaligned during printing speed increase or paster (automatic paper splicing), the corresponding ink The printed portion with a small amount of color may be displaced and the accuracy of color tone control may be greatly reduced.

  Therefore, paying attention to the fact that the edge portion on the outer periphery of the region having a high autocorrelation may be adjacent to a blank paper portion on which any color is not printed, for example, as shown in FIGS. As indicated by a broken line, a region (shaded portion) obtained by removing an edge portion indicated by oblique lines from a region having a high autocorrelation is set as a target pixel region. Here, as shown in the enlarged view of FIG. 4, an area (shaded portion) excluding only one pixel (shaded portion) in the sensor pixel unit of the edge portion is set as the target pixel region.

  Note that the region excluding the edge portion from the region having a high autocorrelation is not limited to one pixel in the sensor pixel unit, but removing the edge portion means that a blank page portion is included in the target pixel region. This is to prevent the decrease in density detection sensitivity by suppressing the decrease in density detection sensitivity. On the other hand, only the removed edge part is removed from the target pixel area, and the target pixel area is reduced accordingly. Therefore, it is conceivable that the accuracy of color tone control is reduced from this aspect. Considering these points, in order to ensure the accuracy of the color tone control, it is preferable to exclude only one pixel in the sensor pixel unit of the edge portion.

  It should be noted that the same effect can be obtained by setting the target pixel region to be expanded outside the region having a high autocorrelation so as to surely include the edge portion instead of the process of removing the edge portion from the target pixel region in this way. Is obtained. That is, the decrease in density detection accuracy occurs when an edge portion of a region having a high autocorrelation is not detected due to a minute position shift at the time of detection. Therefore, instead of narrowing the pixel area of interest so that the vicinity of the edge portion is not always detected even if there is a minute positional shift at the time of detection, the vicinity of the edge portion is detected even if there is a small positional shift at the time of detection. Even if the pixel region of interest is expanded so that it is always detected, it is possible to prevent a decrease in density detection accuracy. Even if only one pixel of the sensor pixel unit in the edge portion is removed, there is a case where there is no target pixel in the low image line. However, such a method of expanding the target pixel region does not cause such a problem, It is effective in the case.

  On the other hand, in the present embodiment, the operator himself designates an arbitrary area on the print surface (preferably the print surface of the plate-making surface 50 based on the plate-making data) displayed on the print area monitor 40 as a touch panel as the first target pixel region. As you can select with your finger. The manual setting of the first target pixel region is performed for each ink color, for example, as shown by hatching in FIGS. 5 (a) to 5 (d). The function related to the manual setting of the target pixel region of the arithmetic device 10 and the print area monitor 40 corresponds to the target pixel region manual setting unit which is one of the first target pixel region setting units. Also in the case of manual setting of the target pixel area, the pixel area is set in units of sensor pixels.

  Thus, the target pixel region (first target pixel region) set according to the guidance in the job ticket data or designated by the operator itself, and the target pixel region automatically set by the target pixel region automatic setting unit The target pixel area can be set in two systems (second target pixel area), but in actual color tone control, the control amount based on each of these target pixel areas is set by weighted averaging, Control is based on this. That is, although details will be described later, the solid density deviation of each ink is used for color tone control, and this solid density deviation is based on each of the first target pixel area and the second target pixel area. The color tone control is performed by calculating and weighting and averaging both solid density deviations according to a preset weighting, and adjusting the ink supply amount for each ink supply unit width based on the weighted average density deviation. It is like that.

  For this reason, the arithmetic device 10 is provided with a function (weighting setting means) for setting the weighting in the case of this weighted average, so that the operator can arbitrarily set the weight using a keyboard or the like attached to the arithmetic device 10. It has become. For example, if the weight of the second target pixel area set with attention to autocorrelation is set to 0%, only the first target pixel area set according to the guidance in the job ticket data is used. If the solid density deviation is calculated and the color tone control is performed, and the weight of the second target pixel area is set to 100%, the solid density deviation is calculated based on only the second target pixel area and the color tone control is performed. Can be set to

  Of course, if the weight of the first target pixel region is set to an appropriate value between 0% and 100%, the solid density deviation is calculated and the color tone control is performed at this ratio. If the weight of the second target pixel area is set to 50%, a solid density deviation obtained by simply averaging the solid density deviation based on the first target pixel area and the solid density deviation based on the second target pixel area is used. Color control is performed.

  In this way, after setting the target pixel area, the target color mixture halftone density for each ink supply unit width of each target pixel area when the printed pattern is divided by the ink supply unit width of the ink supply device is set in the plate making data. Set based on picture information.

Hereinafter, with reference to FIGS. 9 and 10, the color tone control process will be described in order.
Here, as shown in FIG. 9, plate-making data [bitmap data (1-bit-Tiff plate-making data) from a base station of a newspaper company, JDF data equivalent to 50.8 dpi, or data converted to the same resolution ( (Page data converted from 1-bit-Tiff data of 1200 dpi or 2400 dpi to 8-bit-Tiff of 50 dpi)]] is obtained (step D10), and the transmitted bitmap data is obtained. The data is converted into low resolution data equivalent to JDF data according to the format of the printing press (step D20), and this low resolution data is used as pixel area ratio data. This resolution conversion process is for sharing with general JDF data, but it is also possible to use the bitmap data itself as pixel area ratio data in subsequent processes.

In step D30, the first target pixel area corresponding to each ink color is automatically set as described above.
In step D50, using the conversion table recorded in the database 141, the halftone dot area ratio ki, ci, mi, yi of the pixel of interest of each ink color that has been automatically set is converted into a mixed color halftone density, which is converted into the target color mixture. Set as the net density Ioa, Roa, Goa, Boa.

  In parallel with steps D30 and D50, in step D40, the second pixel region of interest corresponding to each ink color is automatically set as described above. In step D60, the conversion table recorded in the database 141 is set. Is used to convert the halftone dot area ratios ki, ci, mi, yi of the target pixel of each ink color set manually into a mixed color halftone density and set it as the target mixed color halftone density Ioh, Roh, Goh, Boh .

  When the target color mixture halftone densities Io, Ro, Go, and Bo are set as described above, the processes after step S10 are repeatedly executed as shown in FIG. First, as step S10, the line sensor type IRGB densitometer 1 measures the reflected light amounts i ', r', g ', b' for each pixel on the entire surface of the print sheet 8. The amount of reflected light i ′, r ′, g ′, b ′ of each pixel measured by the IRGB densitometer 1 is input to the DSP 11.

In step S20, the DSP 11 performs a moving average of the reflected light amounts i ′, r ′, g ′, and b ′ of each pixel in units of a predetermined number of printed sheets, so that the reflected light amounts i, r of each pixel from which the noise component has been removed. , G, b are calculated.
Then, as step S30a, the actual mixed color halftone densities I, R, G, B of the first target pixel of each color are calculated using the reflected light amounts i, r, g, b of each pixel calculated in step S20, In step S30b, the actual mixed color halftone densities I, R, G, and B of the second target pixel of each color are calculated using the reflected light amounts i, r, g, and b of each pixel calculated in step S20.

  The DSP 11 calculates the target color mixture halftone density Io, Ro, Go, Bo from the reflected light amount i, r, g, b of the target point of the plate-making image and the reflected light amount of the blank paper portion, and the printing sheet (print sheet) 8 The actual mixed-color halftone densities I, R, G, and B are calculated from the reflected light amounts i, r, g, and b of the target point and the reflected light amount of the blank paper portion. Since the target pixel is basically a set of a plurality of pixels, the reflected light amounts i, r, g, and b are averaged by the plurality of pixels constituting the target pixel. For example, assuming that the reflected light amount of infrared light on a blank paper portion is ip and the average reflected light amount of infrared light in the key zone is ik, the actual mixed color halftone density I of infrared light is I = log10 (ip / ik). Desired. The actual mixed color halftone densities I, R, G, B for each key zone calculated by the DSP 11 are input to the color conversion unit 14 of the PC 12.

The color conversion unit 14 performs the processes of steps S40a, S50a, and S60a and the processes of steps S40b, S50b, and S60b.
First, in step S40a, the target color mixture density Io, Ro, Go, Bo of the first target pixel of each color set in step D50 and the actual color mixture network of the first target pixel of each color calculated in step S30a. The dot area ratio of each ink color corresponding to the densities I, R, G, and B is calculated. In step S40b, the target color mixture density Io, Ro, Go, Bo of the second target pixel of each color set in step D60 and the actual color mixture network of the second target pixel of each color calculated in step S30b. The dot area ratio of each ink color corresponding to the densities I, R, G, B is calculated in the same manner as in step S40a. For these calculations, the database 141 is used, and based on the correspondence stored in the database 141, the halftone dot area ratio of each ink color corresponding to the target color mixture halftone density Io, Ro, Go, Bo is calculated as the target halftone dot area ratio ko. , Co, mo, yo and the halftone dot area ratio of each ink color corresponding to the actual mixed color halftone density I, R, G, B is calculated as the actual halftone dot area ratio k, c, m, y.

  Next, in step S50a, the color conversion unit 14 selects each ink corresponding to the target halftone dot area ratios ko, co, mo, yo and the real halftone dot area ratios k, c, m, y calculated in step S40a. The monochrome halftone density of each color is calculated. Further, as step S50b, the monochrome halftone densities of the respective ink colors corresponding to the target halftone dot area ratios ko, co, mo, yo and the real halftone dot area ratios k, c, m, y calculated in step S40b, respectively. Calculate. A map as shown in FIG. 11 is used for these calculations. FIG. 11 is an example of a map obtained by plotting the monochromatic halftone density actually measured when the halftone dot area ratio is changed as a characteristic curve, and is created from data measured in advance. In the example shown in FIG. 11, by comparing the black target halftone dot area ratio ko and the real halftone dot area ratio k with the map, the target single color halftone density Dako and the real single color halftone density Dak are obtained from the characteristic curves in the map. It has been demanded. In this way, the color conversion unit 14 obtains the target monochromatic halftone densities Dako, Dako, Damo, Dayo and the actual monochromatic halftone densities Dak, Dac, Dam, Day for each ink color.

  Next, in step S60a, the color conversion unit 14 sets each color corresponding to the deviation between the first target pixel target single color halftone density Dako, Dako, Damo, Dayo and the actual single color halftone density Dak, Dac, Dam, Day for each color. Ink color solid density deviations ΔDsk1, ΔDsc1, ΔDsm1, and ΔDsy1 are calculated. Further, as step S60b, the solid density deviation ΔDsk2 of each ink color corresponding to the deviation between the second target pixel target monochrome color density Dako, Dako, Damo, Dayo and the actual monochrome color density Dak, Dac, Dam, Day of each color. , ΔDsc2, ΔDsm2, ΔDsy2 are calculated.

  The solid density also depends on the halftone dot area ratio. For the same monochrome halftone density, the higher the halftone dot area ratio, the lower the solid density. Therefore, the color conversion unit 14 performs calculation using a map as shown in FIG. FIG. 12 is an example of a map in which the monochromatic halftone density actually measured when the monochromatic solid density is changed is plotted as a characteristic curve for each halftone dot area ratio, and is created from data measured in advance. The color conversion unit 14 selects a characteristic curve corresponding to the target halftone dot area ratios ko, co, mo, and yo for each ink color from the map shown in FIG. 12, and sets the target monochromatic halftone densities Dako, Daco, The solid density deviations ΔDsk1, ΔDsc1, ΔDsm1, ΔDsy1, ΔDsk2, ΔDsc2, ΔDsm2, ΔDsy2 are obtained by associating the Damo, Dayo and the actual monochromatic halftone densities Dak, Dac, Dam, Day. In the example shown in FIG. 12, when the target halftone dot area ratio ko of black is 75%, the target single color halftone density Dako and the actual single color halftone density Dak are checked against the map, so that the black color is obtained from the 75% characteristic curve in the map. The solid density deviation ΔDsk is obtained.

As described above, when the solid density deviations ΔDsk1, ΔDsc1, ΔDsm1, and ΔDsy1 based on the first target pixel and the solid density deviations ΔDsk2, ΔDsc2, ΔDsm2, and ΔDsy2 based on the second target pixel are calculated, both solids are obtained in step S65. The density deviations are weighted and averaged according to preset weights to obtain solid density deviations ΔDsk, ΔDsc, ΔDsm, and ΔDsy. The solid density deviations ΔDsk, ΔDsc, ΔDsm, and ΔDsy can be calculated by the following equation if the weight of the second target pixel that is manually set is set to A percent.
ΔDsk = (1−A) · ΔDsk1 + A · ΔDsk2
ΔDsc = (1−A) · ΔDsc1 + A · ΔDsc2
ΔDsm = (1−A) · ΔDsm1 + A · ΔDsm2
ΔDsy = (1−A) · ΔDsy1 + A · ΔDsy2
The solid density deviations ΔDsk, ΔDsc, ΔDsm, ΔDsy of each ink color calculated by the color conversion unit 14 are input to the ink supply amount calculation unit 15. In step S70, the ink supply amount calculation unit 15 calculates key opening deviation amounts ΔKk, ΔKc, ΔKm, and ΔKy corresponding to the solid density deviations ΔDsk, ΔDsc, ΔDsm, and ΔDsy. The key opening deviation amounts ΔKk, ΔKc, ΔKm, ΔKy are the current key opening Kk0, Kc0, Km0, Ky0 of each ink key 7 (the key opening output to the control device 20 of the printing press in the process of the previous step S100). Kk, Kc, Km, Ky), and the ink supply amount calculation unit 15 performs calculation using a known API function (auto-preset inking function). The API function is a function showing the correspondence between the image area ratio A (Ak, Ac, Am, Ay) and the key opening K (Kk, Kc, Km, Ky) in each key zone in order to obtain the reference density. As the line drawing ratio A, the one used in step S0 can be used. Specifically, the ratio kd (kd = ΔDs / Ds) of the solid density deviation ΔDs (ΔDsk, ΔDsc, ΔDsm, ΔDsy) with respect to the reference density Ds (Dsk, Dsc, Dsm, Dsy) is obtained, and at the same time with respect to the line drawing rate A A key opening K for obtaining a reference concentration is obtained using an API function, and a key opening deviation amount ΔK (ΔK = kd × K) for making the solid concentration deviation ΔDs zero is obtained as a product of these.

Next, in step S80, the online control unit 16 uses the key opening deviation amounts ΔKk, ΔKc, ΔKm, ΔKy calculated by the color conversion unit 14 as the printing units 2a, 2b, 2c, 2 respectively.
Correction is made in consideration of the dead time from d to the line sensor type IRGB densitometer 1, the reaction time of the ink key 7 per hour, and the printing speed. This correction is detected as a change in the amount of reflected light by the IRGB densitometer 1 when the ink key 7 is moved after the key opening signal is input, the key opening is changed and the amount of ink supplied to the printing sheet changes. The time delay until is taken into consideration. As such an online feedback control system with a large dead time, for example, PI control with dead time compensation, fuzzy control, robust control and the like are optimal. The online control unit 16 is for online control in which the current key opening Kk0, Kc0, Km0, Ky0 is added to the corrected key opening deviation (online control key opening deviation) ΔKk, ΔKc, ΔKm, ΔKy. The key opening degrees Kk1, Kc1, Km1, and Ky1 are input to the key opening limiter calculation unit 17.

  In step S90, the key opening limiter calculation unit 17 performs correction for restricting the upper limit value for the online control key openings Kk1, Kc1, Km1, and Ky1 calculated by the online control unit 16. This is a process for restricting an abnormal increase in the key opening due to the estimation error of the color conversion algorithm (the processes in steps S40, S50, and S60) particularly in the low image area. Then, in step S100, the key opening limiter calculating unit 17 transmits the key opening Kk, Kc, Km, Ky whose upper limit value is restricted as a key opening signal to the control device 20 of the printing press.

  In step S110, the control device 20 of the printing press determines the opening of each ink key 7 of each printing unit 2a, 2b, 2c, 2d based on the key opening signals Kk, Kc, Km, Ky transmitted from the arithmetic unit 10. Adjust. As a result, the ink supply amount of each ink color is controlled to match the target color tone for each key zone.

  According to the target pixel area setting method and apparatus for color tone control of printing and the color tone control method and apparatus according to the present embodiment, the person in charge of the page configuration such as the designer of the page to print the plate making data and the job ticket data for printing At the time of creation, information about the pixel area of interest corresponding to the above-mentioned plate making data (type of whether the point of interest specified by the client or the point of interest that the designer thinks important, solid, mesh, or flat screen) is selected in the job ticket data Since writing is performed, the printing operator only needs to check the check column based on the written information regarding the target pixel area at the time of printing, the burden on the operator is reduced, and the target pixel area can be set appropriately in a short time. Can be done. In addition, when the attention point designated by the client or the attention point considered important by the designer is specifically designated as coordinates and arms, the pixel area of interest can be selected as it is from this coordinate information, and the burden on the operator is further increased. Thus, the pixel region of interest can be set appropriately in a shorter time.

For this reason, even when it is necessary to complete a short period of time from paper editing to printing completion, such as newspaper printing, the target pixel area can be appropriately set, and printing is performed based on the target pixel area. Can be accurately controlled.
Also, it is possible to automatically check the above check column using the PC 12, and the target pixel region can be appropriately set without requiring any artificial processing.

  In particular, the solid area or the flat mesh area is set to an area in which the image differential (difference from adjacent pixels) value of the dot area ratio of the printed pattern is equal to or less than a preset reference value (for example, 1%). Is a region where the halftone dot area ratio of the printed pattern is equal to or greater than a preset reference value (for example, 70%), and the halftone dot area ratio of the printed pattern is less than the reference value (for example, 70%). By setting the area, automatic selection of each area of the solid area, the net area, and the flat net area can be easily performed, which contributes to the automatic setting of the target pixel area.

  In addition, by setting an area obtained by removing the edge portion of the target pixel area by a predetermined number of sensor pixels as the target pixel area used for printing tone control, other areas including a blank area are not included in the target pixel area. It is possible to prevent a decrease in density detection sensitivity even when there is a difference between the target image position and the current image position when the printing speed is increased or when the paster (automatic paper splicing) is performed. Can be suppressed. In addition, if the target pixel area is set to be expanded outside the area with high autocorrelation, the target pixel area can be reliably secured even in the case of a low image line, and the decrease in accuracy of color tone control is suppressed. can do.

  Further, apart from the first target pixel area setting based on job ticket data or the like, based on the kcmy halftone dot area ratio data of the plate making data, an area having a high autocorrelation for each ink color is determined as a sensor pixel of the IRGB densitometer. Since the second pixel-of-interest area is set based on this selected area, sensing is performed using a different scale (area with high autocorrelation) from the scale of attention point selection by the person in charge of creating the page configuration. Therefore, it is possible to set a pixel region of interest in which the control accuracy is most improved when considered from the above, and it is possible to improve the control performance. The first pixel-of-interest area has human priority, and the second pixel-of-interest area has computer priority. Therefore, at the second pixel-of-interest, there is a feature that a pixel having a low positional sensitivity or color sensitivity is not selected.

  Further, if the target pixel disappears if the edge portion is removed by a predetermined number of sensor pixels, all the regions having high autocorrelation are excluded from the selected region without removing the edge portion. If the target pixel area is set, the present invention can be applied to a small selection area (area with high autocorrelation) in which the target pixel disappears by removing the edge portion by a predetermined number of pixels.

In addition, the intention of the operator can be reflected at an appropriate ratio by performing weighted averaging of the target pixel region set in two systems by weighting setting.
Therefore, if the weight of the first target pixel region is set to 100% or close to this, color tone control (ink supply amount control) that strongly reflects the intention of the paper surface creation part can be performed. On the other hand, when the control is performed without relying much on the paper surface creation part, if the weighting of the first target pixel region is set to 0 percent or close to this, a standard automatically set according to the objective standard by the control device 10 is used. Appropriate color tone control (ink supply amount control) based on the target pixel can be realized.

(B) Others Although the embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above.
For example, in this embodiment, the pixel region of interest set in two systems is weighted average, and the weighting related to the weighted average can be set freely. It is possible to select only three patterns of the first target pixel area (100%), the objective reference priority by the control device 10 (second target pixel area 100%), and the simple average (both 50%). Simply, it is possible to select one of the paper creation part intention priority (first target pixel area 100%) and the objective reference priority (second target pixel area 100%) by the control device 10. Good. Even if only the first target pixel region is employed, a certain effect can be obtained.

Furthermore, a simple sum of the first target pixel region and the second target pixel region may be used as the target pixel region regardless of weighting.
In this embodiment, in addition to a method including a database 141 that associates the halftone dot area ratio of each ink color with the mixed color halftone density, a publicly known method that defines the correspondence between the halftone dot area ratio of each ink color and the mixed color halftone density. The Neugebauer equation is stored, and the halftone dot area ratio of each ink color is applied to this equation to calculate the mixed color halftone density.

  Further, in addition to a method for obtaining a solid density deviation of each ink color corresponding to the deviation between the target monochrome color density and the actual monochrome color density using a map as shown in FIG. 12, the dot area ratio, the monochrome color density, and the solid color are obtained. A method of calculating a solid density deviation by storing a known Yule-Nielsen formula that defines the correspondence with density and applying the target halftone dot area ratio, actual halftone dot area percentage, and monochrome halftone density to this formula is also available. is there.

In the embodiment, a line sensor type IRGB densitometer is used as a sensor for measuring density . However, a spot type IRGB densitometer may be used to scan the print sheet two-dimensionally.

1 is a diagram showing a schematic configuration of a newspaper offset rotary press according to an embodiment of the present invention. It is a functional block diagram which paid its attention to the color tone control function of the arithmetic unit of FIG. It is a figure which shows the printing surface explaining automatic selection of the attention pixel area | region concerning one Embodiment of this invention, (a)-(d) shows the example of an automatic setting area | region, respectively. It is a figure which shows the printing surface explaining automatic selection of the attention pixel area | region concerning one Embodiment of this invention. It is a figure which shows the printing surface explaining manual selection of the attention pixel area | region concerning one Embodiment of this invention, (a)-(d) shows the example of a manual setting area | region, respectively. It is a flowchart explaining selection of the attention pixel area concerning one Embodiment of this invention. 4A and 4B are diagrams for describing setting of a target pixel area (solid, mesh) according to the first embodiment of the present invention, where FIG. 5A is a flowchart, FIG. 5B is a diagram illustrating a screen display of the setting, and FIG. It is a figure which shows the kind of area | region. 4A and 4B are diagrams for explaining selection of a target pixel region (flat mesh) according to the first embodiment of the present invention, where FIG. 5A is a flowchart, and FIG. 3 is a flowchart illustrating a processing flow of color tone control (including setting of a target pixel region) by the arithmetic device of FIG. 1. It is a flowchart which shows the processing flow of the color tone control by the arithmetic unit of FIG. 6 is a map that associates a monochrome halftone density with a halftone dot area ratio. 6 is a map that associates a solid density with a halftone dot area ratio and a monochrome halftone density. It is a figure for demonstrating the subject regarding this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Line sensor type IRGB densitometer 2a, 2b, 2c, 2d Printing unit 3 Blanket cylinder 4 Plate cylinder 5 Ink roller group 6 Ink source roller 7 Ink key 8 Printing sheet 10 Arithmetic unit 11 DSP
12 PC
14 Color Conversion Unit 15 Ink Supply Amount Calculation Unit 16 Online Control Unit 17 Key Opening Limiter Calculation Unit 20 Control Device Built in Printing Machine 30 Touch Panel 32 Display Device 40 Print Area Monitor (Touch Panel)
50 printing side

Claims (22)

A method for setting a pixel region of interest for each ink color used in feedback control of a print color tone by paying attention to a specific pixel region in a printed pattern,
A pixel-of-interest area information writing step of writing information on the pixel-of-interest area corresponding to the plate-making data into the job ticket data when creating the plate-making data and printing job ticket data;
In performing printing based on the plate-making data and the job ticket data, the pixel-of-interest region setting step of setting the pixel-of-interest region in a printed pattern based on the information on the pixel-of-interest region written,
The information on the target pixel area is color tone control characterized in that it is selection information for selecting at least one of a solid area, a halftone area, and a flat halftone area as the target pixel area. Attention pixel region setting method. Upper Kitaira network region, and wherein the image differential value of the halftone dot area ratio of the printing picture is a preset reference value or less in the region, according to claim 1, wherein the color tone controlling noticed pixel region setting method . The solid area is an area where the value of the halftone dot area ratio of the printed pattern is equal to or greater than a preset reference value, and the halftone area of the printed pattern is less than the reference value The method for setting a target pixel region for color tone control according to claim 1, wherein the pixel region is a region. 4. The color tone control according to claim 1, wherein in the target pixel region setting step, the target pixel region is manually or automatically set based on information on the target pixel region. Attention pixel region setting method. 5. The pixel region of interest that is used for color tone control of printing is a region obtained by removing the edge portion of the set pixel region of interest by a predetermined number of sensor pixels. 6. 2. A method for setting a pixel area of interest for color tone control described in 1. The target pixel region setting step performed based on the information on the target pixel region is set as a first target pixel region setting step, and, separately from the first target pixel region setting step, halftone dot area ratio data of plate making data is used. Based on this, a region having a high autocorrelation for each ink color is selected for each sensor pixel of the sensor for measuring the amount of reflected light, and the edge portion of the corresponding ink color is removed from the selected region by a predetermined sensor pixel. 6. The color tone control device according to claim 1, further comprising a second target pixel region setting step of setting the region as the target pixel region of the corresponding ink color. Attention pixel area setting method. The target pixel region setting step performed based on the information on the target pixel region is set as a first target pixel region setting step, and, separately from the first target pixel region setting step, halftone dot area ratio data of plate making data is used. A step of setting the pixel region of interest based on the selected region, wherein a region having a high autocorrelation for each ink color is selected for each sensor pixel of the sensor for measuring the amount of reflected light, and the corresponding ink color is selected from the selected region. If the pixel region of interest exists even if the edge portion is removed by a predetermined sensor pixel, the region in which the edge portion is removed from the selected region by the predetermined sensor pixel is removed from the selected region. If it is set as the target pixel area and the edge part is removed by the predetermined sensor pixels, the target pixel area disappears. 2. The method according to claim 1, further comprising a second target pixel region setting step for setting the region having a high autocorrelation without removing the edge portion as the target pixel region of the corresponding ink color. 6. A method for setting a target pixel area for color tone control according to any one of items 1 to 5. In the second pixel-of-interest region setting step, when the corresponding ink color edge portion is removed from the selected region in the sensor pixel unit, only one pixel is removed in the sensor pixel unit. The method for setting a target pixel area for color tone control according to claim 6 or 7 . The target pixel region setting step performed based on the information on the target pixel region is set as a first target pixel region setting step. Separately from the first target pixel region setting step, each ink color is determined based on the plate making data. A region with a high autocorrelation was selected for each sensor pixel of the sensor that measures the amount of reflected light, and was expanded from the selected region to the outside of the region with a high autocorrelation so as to include the edge portion of the corresponding ink color. 6. The target pixel region setting method for color tone control according to any one of claims 1 to 5, further comprising a second target pixel region setting step for setting a region as the target pixel region. . The region having a high autocorrelation in the second target pixel region setting step is a group of all pixels having a high autocorrelation higher than a preset condition for each ink color,
The second noticed pixel region setting step, characterized in that it is configured as a noticed pixel region automatically setting step of automatically extracting the pixel group by using a computer, according to any one of claims 7-9 Of interest pixel region setting method for color tone control. The sum area of the first target pixel area set by the first target pixel area setting step and the second target pixel area set by the second target pixel area setting step is set as the target pixel area. The method for setting a target pixel region for color tone control according to any one of claims 7 to 10 , wherein: There in claim 1 to 11 any one printing press picture color tone controlling method for feedback control of the color tone of interest to the printing target pixel area set by using the color tone control noticed pixel region setting method according to the And
A target color mixture halftone density setting step for setting a target color mixture halftone density relating to the target pixel region;
Using sensors, and the actual color mixture halftone density measurement step of measuring an actual color mixture halftone density regarding the noticed pixel region for each ink color for each Yi Nki supplying unit widths of the printing sheet obtained in printing,
A target halftone dot area ratio calculating step for obtaining a target halftone dot area ratio of each ink color corresponding to the target mixed color halftone density based on a correspondence relationship between a predetermined halftone dot area ratio and mixed color halftone density;
Based on the correspondence between the halftone dot area ratio and the mixed color halftone density, an actual halftone dot area ratio calculation step for obtaining the actual halftone dot area ratio of each ink color corresponding to the actual mixed color halftone density;
A target monochromatic halftone density calculating step for obtaining a target monochromatic halftone density corresponding to the target halftone dot area ratio based on a correspondence relationship between a predetermined halftone dot area ratio and a monochromatic halftone density;
An actual monochromatic halftone density calculating step for obtaining an actual monochromatic halftone density corresponding to the actual halftone dot area ratio based on the correspondence relationship between the halftone dot area ratio and the monochromatic halftone density;
Based on the correspondence relationship between the halftone dot area ratio, the monochrome halftone density, and the solid density set in advance, for the target pixel area, the target monochrome halftone density and the actual monochrome halftone density under the target halftone dot area ratio A solid density deviation calculating step for obtaining a solid density deviation corresponding to the deviation of
A picture color tone control method for a printing press, comprising: an ink supply amount adjusting step for adjusting an ink supply amount for each ink supply unit width based on the solid density deviation. With use of the color tone control noticed pixel region setting method according to any one of claims 6-11,
The target mixed color halftone density setting step, the actual mixed color halftone density measuring step, the target halftone dot area ratio calculating step, the actual halftone dot area ratio calculating step, the target single color halftone density calculating step, the actual single color halftone density calculating step, and the solid density deviation The calculation step is performed for both the first target pixel region set by the first target pixel region setting step and the second target pixel region set by the second target pixel region setting step. 13. The pattern color tone of a printing press according to claim 12 , wherein, in the ink supply amount adjustment step, the ink supply amount is adjusted for each ink supply unit width based on the two solid density deviations obtained therefrom. Control method. In the ink supply amount adjustment step, the solid density deviation obtained with respect to the first target pixel area and the solid density deviation obtained with respect to the second target pixel area are set according to a preset weighting. 14. The pattern color tone control method for a printing press according to claim 13 , wherein the ink supply amount is adjusted for each of the ink supply unit widths based on the weighted average solid density deviation. An apparatus for setting a pixel region of interest for each ink color, which is used when feedback-controlling the color tone of printing by paying attention to a specific pixel region in a printed pattern,
A writing means for writing information on the noticed pixel region corresponding to the plate making data to the plate making data and the print job ticket data,
An arithmetic unit that controls printing based on the plate-making data and the job ticket data and automatically sets the pixel region of interest based on information on the pixel region of interest;
The information on the target pixel area is selection information for selecting at least one of a solid area, a halftone area, and a flat halftone area as the target pixel area. A target pixel area setting device for color tone control. Upper Kitaira network region, and wherein the image differential value of the halftone dot area ratio of the printing picture is a region below a preset reference value, according to claim 15 tone control target pixel areas of the printing according Setting device. The solid area is an area where the value of the halftone dot area ratio of the printed pattern is equal to or greater than a preset reference value, and the halftone area of the printed pattern is less than the reference value 17. The target pixel region setting device for color tone control of printing according to claim 16, wherein the pixel region is a region. 18. The arithmetic device according to claim 15 , wherein a pixel region in which an edge portion is removed by a predetermined number of sensor pixels from the set target pixel region is set as a target pixel region used for color tone control of printing. The target pixel region setting device for color tone control of printing according to any one of the above. The arithmetic unit includes a first target pixel region setting unit that sets a target pixel region based on the information about the target pixel region and a first target pixel region setting unit, based on plate making data. A region with a high autocorrelation for each ink color is selected for each sensor pixel of the sensor that measures the amount of reflected light, and a region obtained by removing the edge portion of the corresponding ink color from the selected region by a predetermined sensor pixel is selected. 19. The target pixel region setting device for color tone control of printing according to claim 15 , further comprising second target pixel region setting means for setting as the target pixel region . The arithmetic unit includes a first target pixel region setting unit that sets a target pixel region based on the information about the target pixel region and a first target pixel region setting unit, based on plate making data. A region having a high autocorrelation for each ink color is selected for each sensor pixel of the sensor for measuring the amount of reflected light, and the region having a high autocorrelation is selected from the selected region so as to include an edge portion of the corresponding ink color. The color tone control for printing according to any one of claims 15 to 17 , characterized in that an area expanded outward is provided with second target pixel area setting means for setting the target pixel area. Attention pixel area setting device. In the arithmetic device, a sum area of the first target pixel region set by the first target pixel region setting unit and the second target pixel region set by the second target pixel region setting unit is calculated. 21. The target pixel region setting device for color tone control of printing according to claim 19 or 20 , wherein the target pixel region is set in a target pixel region. A target pixel area setting device for color control of printing according to any one of claims 15 to 21 ,
A sensor arranged on the running line of the main printed sheet obtained by printing;
A target color mixture halftone density setting means for setting a target color mixture halftone density regarding the noticed pixel region of each divided Lee Nki supplying unit width in the print width direction,
A mixed color halftone density measuring means for measuring the actual mixed color halftone density for each ink supply unit width of the main printing sheet by operating the sensor;
A target halftone dot area ratio calculating means for obtaining a target halftone dot area ratio of each ink color corresponding to the target mixed color halftone density based on a correspondence relationship between a predetermined halftone dot area ratio and the mixed color halftone density;
Based on the correspondence between the halftone dot area ratio and the mixed color halftone density, an actual halftone dot area ratio calculating means for obtaining the actual halftone dot area ratio of each ink color corresponding to the actual mixed color halftone density,
A target monochromatic halftone density calculating means for obtaining a target monochromatic halftone density corresponding to the target halftone dot area ratio based on a correspondence relationship between a predetermined halftone dot area ratio and a monochromatic halftone density;
Based on the correspondence between the halftone dot area ratio and the monochromatic halftone density, an actual monochromatic halftone density calculating means for obtaining an actual monochromatic halftone density corresponding to the actual halftone dot area ratio;
Based on the correspondence relationship between the halftone dot area ratio, the monochrome halftone density, and the solid density set in advance, the solid corresponding to the deviation between the target monochrome halftone density and the actual monochrome halftone density under the target halftone dot area ratio. Solid density deviation calculating means for obtaining density deviation;
An image color tone control device for a printing press, comprising: an ink supply amount adjusting means for adjusting an ink supply amount for each ink supply unit width by feedback control based on the solid density deviation.

Images