JP2005151172A - Print controller, print control method, and print control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an image with the quality of a print result image approximately kept constant in a print step without needing to print a special image such as a test pattern, etc. <P>SOLUTION: The print control method comprises a step S30 for acquiring the feature quantity extracted from a print result image formed on a printing medium on the basis of original image data, and a step S36 of holding the feature quantity acquired in the feature quantity acquiring step with the original image data related thereto as a feature quantity history database. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a print control apparatus, a print control method, and a print control program that can improve the quality of a print result image from an image forming apparatus.

  In order to control the image quality of print results output from image forming devices such as printers and copiers, multiple reference patches with different densities are created on the paper, and the density of the created reference patches is measured with a density sensor. The gradation correction data is created based on the comparison between the highlight gradation correction condition corresponding to the vicinity of the minimum density value output from the image forming apparatus and the reference patch measured by the density sensor, and the subsequent printing conditions are set. Techniques for automatic control are disclosed (for example, JP-A-8-292616 and JP-A-8-251414).

  Also disclosed is a technique for performing gradation correction by providing an image scanner in an image forming apparatus. Print a test pattern for correction on paper, extract the test pattern characteristic value obtained by reading the test pattern on the paper with an image scanner, and perform automatic correction of gradation characteristics based on the characteristic value (for example, JP-A Nos. 11-284794 and 2002-262092).

  When a large amount of the same original image is continuously printed, the gradation of the print result image gradually changes. Therefore, in order to keep the gradation of the print result image constant, it is necessary to perform printing while adjusting the gradation.

  Therefore, a technique for determining whether the color density of the printing result is good or not when performing continuous printing is also disclosed. For example, when printing, a test pattern to be a color sample is printed on a part of the paper, a measurement area of the print result and a color sample are simultaneously photographed with a video camera, and the color sample is photographed. A technique for determining whether or not the color density of a printing result is acceptable based on the color sample image data is disclosed (Japanese Patent Laid-Open No. 9-141837).

JP-A-8-292616 JP-A-8-251414 Japanese Patent Laid-Open No. 11-284794 JP 2002-262092 A Japanese Patent Laid-Open No. 9-141837

  In the above conventional technique, a test pattern must always be printed in order to detect a change in the gradation of a printed image. However, if the test pattern and the document image data to be printed are printed at the same time, there is a problem that the layout of the document image is disturbed. Even if the test pattern is printed on the margin of the paper, an extra process such as cutting off the portion where the test pattern is printed after printing is required.

  Also, when printing different original image data after printing some original image data and then printing the previous original image data again, the previous print result and the current print result for the same original image data It was not possible to confirm whether or not the same printing result was obtained. Furthermore, when the same document image data is printed at time intervals, the printing conditions cannot be corrected so that the same image quality as the previous printing result can be obtained.

  An object of the present invention is to provide a print control apparatus, a print control method, and a print control program that can correct image quality variations even during continuous printing.

  The present invention provides a feature amount acquisition unit that acquires a feature amount extracted from a print result image formed on a print medium based on document image data, a feature amount acquired by the feature amount acquisition unit, and the document image The printing control apparatus includes storage means for associating data and holding the data as a feature amount history database.

  Further, it is preferable that the feature amount acquisition unit acquires a feature amount extracted from a region of interest predetermined for each document image data. At this time, the feature amount can be a gradation of an image.

  Furthermore, a history data extraction unit that extracts, as history data, a feature amount that is stored in association with the document image data from the feature amount history database, a feature amount acquired by the feature amount acquisition unit, and the history data extraction It is preferable to include correction condition setting means for setting a correction condition for forming the original image data based on the history data extracted by the means.

  At this time, the correction condition setting unit calculates a difference between the feature amount acquired by the feature amount acquisition unit and the history data extracted by the history data extraction unit, and sets the correction condition based on the difference. can do.

  In addition, it is preferable that the storage unit holds the feature amount acquired by the feature amount acquisition unit and the attribute of the document image data in association with each other.

  The present invention provides a feature amount acquisition step of acquiring a feature amount extracted from a print result image formed on a print medium based on document image data, the feature amount acquired in the feature amount acquisition step, and the document image The print control method includes a history data registration step of associating data with each other and holding the data as a feature amount history database.

  In the feature amount acquisition step, it is preferable to acquire a feature amount extracted from a region of interest predetermined for each document image data. At this time, the feature amount can be a gradation of an image.

  Further, a history data extracting step of extracting, as history data, a feature amount associated with the document image data from the feature amount history database, a feature amount acquired in the feature amount acquiring step, and the history data extraction And a correction condition setting step of setting a correction condition for forming the original image data based on the feature amount extracted in the process.

  At this time, in the correction condition setting step, a difference between the feature amount acquired in the feature amount acquisition step and the feature amount extracted in the history data extraction step is calculated, and the correction condition is set based on the difference. can do.

  In the history data registration step, it is preferable that the feature amount acquired in the feature amount acquisition step and the attribute of the document image data are stored in association with each other.

  The present invention provides a feature amount acquisition unit that acquires a feature amount extracted from a print result image formed on a print medium based on original image data, and a storage unit that includes the feature amount According to another aspect of the invention, there is provided a print control program that functions as a print control apparatus including a history data registration unit that associates the feature amount acquired by the acquisition unit with the document image data and stores the feature amount as a feature amount history database.

  Further, it is preferable that the feature amount acquisition unit acquires a feature amount extracted from a region of interest predetermined for each document image data. At this time, the feature amount may be a gradation of an image.

  A history data extracting unit for extracting, as history data, a feature amount stored in association with the document image data from the feature amount history database; and a feature amount acquired by the feature amount acquiring unit; It is preferable to function as a print control apparatus including correction condition setting means for setting correction conditions for image formation of the document image data based on the history data extracted by the history data extraction means.

  The correction condition setting unit calculates a difference between the feature amount acquired by the feature amount acquisition unit and the history data extracted by the history data extraction unit, and sets the correction condition based on the difference. be able to.

  It is also preferable that the storage unit stores the feature amount acquired by the feature amount acquisition unit and the attribute of the document image data in association with each other.

  According to the present invention, it is possible to perform image formation while maintaining the image quality of the print result image substantially constant in continuous printing and intermittent printing without the need to print a special image such as a test pattern. In particular, the effect is remarkable in an area where the image quality of a company logo or the like should be kept constant.

  As shown in FIG. 1, the print control apparatus 100 according to the embodiment of the present invention is used by a system configuration connected to an image forming apparatus 200 and an inspection apparatus 300 via an information transmission medium such as a bus or a network.

  Examples of the image forming apparatus 200 include a printer, a copier, a digital multifunction machine, and the like. The image forming apparatus 200 can be configured to include a control unit 201, a document image data acquisition unit 202, a paper feeding unit 203, a printing unit 204, a paper discharge unit 205, and a data interface 206.

  When the image forming apparatus 200 is an electrophotographic printer having a copying function, the document image data obtaining unit 202 includes a platen 222 and a scanner 224, and the sheet feeding unit 203 includes a sheet stocker 230 and a sheet conveying belt 232, and printing unit. Reference numeral 204 includes a charging unit 240, an exposure unit 241, a developing unit 242, a photosensitive member 243, a transfer unit 244, a fixing unit 245, and the like, and the paper discharge unit 205 includes a paper discharge stocker 250.

  Using the data interface 206, the image forming apparatus 200 receives document image data to be printed from the print control apparatus 100 via a network or the like. The control unit 201 converts the document image data received from the document image data acquisition unit 202 into a so-called halftone image (halftone image) and transmits it to the printing unit 204.

  The printing unit 204 forms an image based on the document image data. In the printing unit 204, the original image data is not printed as it is, but the printing conditions are adjusted so as to obtain a printing result image according to the printer characteristics and the user's preference. The control unit 201 uses the data interface 206 to receive correction conditions for document image data from the print control apparatus 100 via a network or the like. Based on the received correction condition, the control unit 201 controls the printing unit 204 so that the original image data is formed as a print result image according to printer characteristics and user preference.

  For example, the gradation of the document image data is corrected based on a lookup table (LUT: Look Up Table) for gradation correction. In the case of color printing, the LUT is generally created for each color of cyan (C), magenta (M), yellow (Y), and black (K). In the case of monochrome printing, the LUT is generally created only for black (K). Based on the LUT, the control unit 201 controls the printing unit 204 so that the gradation of each color of the document image data is expressed in an appropriate toner amount and halftone mode. Document image data correction processing using an LUT is performed not only in an electrophotographic printer but also in other types of image forming apparatuses.

  The paper feeding unit 203 supplies paper necessary for printing from the paper stocker 230 to the printing unit 204 by the paper transport belt 232. The printing unit 204 prints document image data received from the control unit 201 on a sheet. After charging the photosensitive member 243 by the charging unit 240, the exposure unit 241 forms document image data on the surface of the photosensitive member 243 as a latent image, the developing unit 242 attaches toner to the latent image on the photosensitive member, and the transfer unit 244. Thus, the toner is transferred onto the sheet, and the fixing unit 245 fixes the toner on the sheet. Through these steps, the original image data is formed on the paper. In the paper discharge unit 205, the paper printed by the printing unit 204 is discharged to the paper discharge stocker 250.

  The document image data may be read by the document image data acquisition unit 202. The scanner 224 is used to read a document image from a document placed on the platen 222, digitize the read document image, and send it to the control unit 201 as document image data. At this time, it is preferable that the document image data read via the network or the like can be transmitted to the print control apparatus 100 using the data interface 206 as necessary.

  Note that the image forming apparatus 200 according to the present embodiment is not limited to the above-described electrophotographic printer as long as it can form original image data to be printed on paper. Further, the paper means not only general paper but also general objects to be printed including OHP sheets, cardboard, and postcards.

  The inspection apparatus 300 is used in combination with the image forming apparatus 200. The inspection apparatus 300 has a function of reading a print result image on a sheet at a later stage than the printing unit 204 of the image forming apparatus 200 and outputting the result as print result image data to the print control apparatus 100. Have. The inspection apparatus 300 can be configured to include an image reading unit 301 and a data interface 302.

  The image reading unit 301 can include a lamp serving as a light source, a line sensor including a photoelectric conversion element, and an analog / digital converter. By illuminating the sheet conveyed using the lamp and photoelectrically converting the light reflected from the sheet using the line sensor, an entire image of the print result image formed on the sheet is obtained. The acquired print result image is digitized by an analog / digital converter to generate print result image data. The print result image data is sent to the print control apparatus 100 via the network using the data interface 302.

  As illustrated in FIG. 2, the print control apparatus 100 includes a control unit 10, a storage unit 12, a data interface 14, and an input / output unit 16. The control unit 10 corresponds to a CPU of a computer, and controls the print control apparatus 100 in an integrated manner by executing a print control program. The storage unit 12 includes a semiconductor memory, and stores and saves electronic information such as a program processed by the control unit 10, image data, and correction conditions. When the data to be stored and held is a large capacity, it is also preferable to use a large capacity storage device such as a hard disk device, a magnetic tape device, a magnetic disk device, an optical disk device, a magneto-optical disk device as an auxiliary storage device. . The data interface 14 is connected to a network and enables information transmission with the data interface 206 of the image forming apparatus 200 and the data interface 302 of the inspection apparatus 300. Using the data interface 14, electronic information such as image data and correction conditions is transmitted and received via a network. The input / output unit 16 includes, for example, a touch panel and the like, and is used for receiving an instruction from the user or presenting information to the user.

  The print control apparatus 100 receives the print result image data transmitted from the inspection apparatus 300, and extracts a feature amount representing image quality from the received print result image data. Further, the correction function is set based on the extracted feature amount, and the correction condition is transmitted to the image forming apparatus 200.

  FIG. 3 is a flowchart of a print control method performed by the print control apparatus 100, the image forming apparatus 200, and the inspection apparatus 300. Each step of the flowchart can be executed after being converted into a print control program that can be processed by a computer.

  In the following, a description will be given of the LUT for correcting the gradation (color tone) of the document image data as the correction condition of the document image data.

  In step S <b> 10, document image data is acquired by the image forming apparatus 200 in the print control apparatus 100. The control unit 10 receives document image data together with a print command from another computer via the network using the data interface 14. Further, the document image data read by the document image data acquisition unit 202 of the image forming apparatus 200 may be acquired via a network.

  The acquired document image data is registered in the storage unit 12 as a document image database. As shown in FIG. 4, the document image database is one in which a unique identification number is sequentially assigned to each document image data and registered. That is, each document image data can be specified by a unique identification number.

  In step S12, a region of interest is designated from the image represented by the document image data. The attention area is an area in which deterioration of image quality is regarded as important in the print result image when the image forming apparatus 200 forms an image of original image data on a sheet. For example, an area in which the gradation is required to be always maintained constant in a print result image, such as a company logo or a sample photograph of a product listed in a catalog, is set as a focused area.

  Specifically, an area that requires image quality inspection is determined in advance for each document image data to be printed, and an area corresponding to the area can be cut out from the print result image data and specified as a region of interest.

  For example, when the document image data is transmitted to the print control apparatus 100 in step S10, the data to be transmitted is designated at the same time as an area of interest.

  When the document image data is bitmap data, the data for specifying the region to be the region of interest is expressed as a set of coordinate data indicating each bit position included in the region of interest. For example, in the example of FIG. 5, in the case of bitmap-format document image data represented by the identification number 001, two coordinates {(0, 0), (50, 50)} are registered in combination. . In this case, it can be determined as data indicating that a rectangular area whose upper left corner is coordinates (0, 0) and whose lower right corner is coordinates (50, 50) is a region of interest.

  Further, when the document image data is expressed in the page description language, the data for specifying the area to be the attention area is represented as a description code indicating the attention area. For example, in the example of FIG. 5, in the case of the document image data in the PDF format represented by the identification number 002, a description code {% BoundingBox: 0 0 50 50} is registered. In this case, it can be determined as data indicating that a rectangular area whose upper left corner is coordinates (0, 0) and whose lower right corner is coordinates (50, 50) is a region of interest.

  The area of interest is registered in the area of interest database in association with an identifier that identifies the corresponding document image data. That is, as shown in FIG. 5, an identifier for specifying the document image data received in step S10, for example, an identification number, is associated with data for specifying the region to be the region of interest and stored in the storage unit 12 as a region of interest data file And hold.

  Here, in order to simplify the explanation, an example in which a simple rectangular area is designated as the attention area has been described. However, data that designates a more complicated shape as the attention area may be registered. A plurality of regions of interest may be designated for each document image data. In this way, by using the attention area database that associates the document image data with the attention area, the attention area can be determined for each document image, or the attention area can be easily changed.

  In step S14, document image data to be printed is designated. The control unit 10 causes the input / output unit 16 to display a list of document image data registered in the document image database and a user interface screen that prompts the user to select document image data to be printed. The user designates document image data to be printed on the user interface screen. The document image data can be designated by an identification number registered in the document image database.

  The document image data received in step S10 may be used as a print target as it is. In this case, a unique identification number is assigned to the received document image data and registered in the document image database, and the identification number is used as a number for specifying the document image data to be printed.

  In step S <b> 16, the document image data to be printed and the correction conditions are transmitted to the image forming apparatus 200. Using the data interface 14, the control unit 10 sends the document image data designated in step S14 and the correction conditions for the document image data to the image forming apparatus 200 via the network.

  Here, when the process proceeds from step S14 to step S16, a standard correction condition is transmitted. For example, if the correction condition is an LUT for gradation correction, as shown in FIG. 6, the LUT for correcting the gradation at the time of printing proportional to the gradation of the document image data is transmitted as a standard LUT.

  On the other hand, when the process proceeds from step S38 to step S16, the correction condition set in step S38 is transmitted to the image forming apparatus 200.

  In step S18, the document image data and the correction conditions are received by the image forming apparatus 200. The control unit 201 uses the data interface 206 to receive document image data and correction conditions from the print control apparatus 100 via the network.

  In step S20, image formation is performed based on the document image data and correction conditions. The control unit 201 transmits the received document image data to the printing unit 204. The printing unit 204 forms an image on a sheet based on the document image data. At this time, the control unit 201 controls printing conditions in the printing unit 204 based on the received correction conditions.

  For example, when an LUT for gradation adjustment is received as a correction condition, the gradation of each color of the document image data is corrected based on the LUT, and the toner is adjusted so that the print result image has the corrected gradation. Control the concentration. For example, when the LUT shown in FIG. 7 is received as a correction condition, if the original image data has an area with a cyan (C) gradation of 100, the gradation is 103 when printing based on the LUT conversion table. Thus, the toner density of cyan (C) is controlled.

  As described above, by forming the original image data while controlling the printing conditions based on the correction conditions, it is possible to obtain a printing result image according to the printer characteristics and the user's preference.

  In step S22, print result image data is acquired. The inspection apparatus 300 reads the print result image printed on the paper in step S20, and acquires digitized print result image data.

  In step S <b> 24, the print result image data is transmitted to the print control apparatus 100. The print result image data acquired in step S22 is transmitted from the inspection apparatus 300 to the print control apparatus 100 via the network using the data interface 302.

  In step S <b> 26, print result image data is received by the print control apparatus 100. The control unit 10 receives the print result image data transmitted from the inspection apparatus 300 via the network using the data interface 14.

  In step S28, the attention area data is specified from the print result document data. The control unit 10 refers to the target region database stored in the storage unit 12 and reads an identifier associated with the document image data to be printed in step S14, that is, a region associated with the identification number. Then, an area corresponding to the read area is cut out from the print result image data received in step S26, and the image data of the area is specified as the attention area data.

  In step S30, feature amounts are extracted from the identified region-of-interest data. The control unit 10 extracts a feature amount from the image data of the region of interest specified in step S14.

  The feature amount is an amount representing the image quality of the image. For example, the gradation (color tone) of each color, the color difference, the sharpness of the edge, and the like can be mentioned. Here, a feature amount controlled as a printing condition when image formation is performed by the image forming apparatus 200 in step S20 is targeted. In particular, feature quantities that are required to be always maintained constant in the region of interest of the document image data are targeted. For example, when color printing is performed while adjusting the gradation based on the LUT, the gradation (density) of red (R), green (G), and blue (B) is extracted.

  An existing image processing method can be used for extracting the feature amount. For example, red (R): 230, green (G): 10, blue (B): 50 as 8-bit data for each color gradation from a company logo mark cut out as a region of interest from print result image data. In this way, the gradation of each color is extracted.

  In step S32, the history data of the feature amount registered for the target area of the document image data to be printed is obtained. The control unit 10 refers to the feature amount history database registered in the storage unit 12 and determines whether or not the feature amount has already been registered for the document image data specified by the identification number specified in step S14. Investigate. If the feature value history is registered in the feature value history database in association with the identification number designated in step S14, the data value is acquired.

  In the feature amount history database, as shown in FIG. 8, feature amounts extracted from the region of interest of document image data that has been printed by the image forming apparatus 200 so far are registered as history data. The registered feature quantity is a feature quantity that is required to be always maintained constant in the print result image of the target area, such as a gradation level extracted from a company logo that is the target area.

  For example, if the document image data specified by the identification number 001 has been a print target in the past, the history data of the feature amount associated with the identification number 001 is registered. In the example of FIG. 8, the gradation of each color is registered as 8-bit data as the feature quantity, and the gradation levels of the region of interest of the document image data specified by the identification number 001 are R: 220, G: 15, B: 55. It is registered as. Further, the document image data specified by the identification number 002 has not been printed yet, and the gradation of the region of interest has not been registered yet.

  In step S34, correction conditions are determined. The control unit 10 sets correction conditions used for the next printing based on the feature amount extracted in step S30 and the feature amount history data read in step S32. If the feature amount is not yet registered for the document image data specified by the identification number specified in step S14 in step S32, no processing is performed in this step, and the correction condition transmitted last in step S16 is set. The new correction condition is used as it is.

  If the feature amount for the document image data specified by the identification number specified in step S14 is registered in step S32, the feature amount extracted in step S30 and the feature amount history data read in step S32 And a correction condition is set based on the difference data.

  For example, when the feature amount is a gradation of each color, the difference data can be expressed by differences ΔR, ΔG, ΔB of the tone data of each RGB color. For example, the identification number 001 of the document image data, the gradation of each color extracted in step S30 is R: 230, G: 10, B: 50, and the history data of the feature amount read in step S32 is When extracted as R: 220, G: 15, and B: 55, the difference data is ΔR = 230−220 = 10, ΔG = 10−15 = −5, and ΔB = 50−55 = −5. When the difference data exceeds a predetermined difference level, gradation correction processing is performed.

  The occurrence of such a difference means that the gradation is R: 220, G: 15, and B: 55 in the focus area of the past print result image, but in the focus area of the print result image printed this time. The gradations are R: 230, G: 10, and B: 50, which means that the gradation of the region of interest has changed due to changes in the mechanical characteristics of the printer over time. Accordingly, the correction condition used for correcting the gradation, that is, the gradation of the R component of the LUT is lowered and the gradation of the G and B components is changed.

  FIG. 9 shows a tone reproducibility curve A for explaining the tone correction processing. In FIG. 9, the horizontal axis represents the gradation (C-in) input to the printing unit 204, and the vertical axis represents the gradation (C-out) read from the region of interest of the print result image data. In the print control apparatus 100, the LUT is set so that the gradation reproducibility curve A matches the target curve B.

  In this way, by storing the history data of the feature amount extracted from the region of interest, it is compared with the feature amount extracted from the newly printed print result image, and the correction condition is determined from the difference as needed. It can be changed. As a result, it is possible to perform image formation of the same document image data while maintaining the image quality of the region of interest constant.

  In step S36, the feature amount history database is updated. The control unit 10 registers the feature amount extracted in step S30 in association with the identification number that specifies the document image data specified in step S14.

  For example, when the document image data specified by the identification number 001 is designated as a printing target in step S14, the feature amount history data associated with the identification number 001 is extracted in step S30 as shown in FIG. Replaced with feature quantity. If no feature quantity has been recorded for the identification number 001, the feature quantity extracted in step S30 is associated with the identification number 001 and newly registered in the feature quantity history database.

  In step S38, it is determined whether or not to continue printing. The control unit 10 counts the number of copies of the original image data designated in step S14, and determines whether or not a predetermined number of prints has been reached. When further printing is performed, the process proceeds to step S16. If the planned number of copies has been reached, the process is terminated.

  As described above, according to the present embodiment, it is possible to perform image formation while maintaining the image quality of the region of interest constant by storing the history data of the feature amount. Also, when the same document image data is formed after a while after printing, it can be determined whether or not the image quality of the region of interest is the same as the previous time. Further, the correction condition can be reset according to the determination result, and control can be performed so that the image quality of the region of interest is kept constant.

  Further, there is no need to print a specific test pattern on the paper, and the image quality of the region of interest can be maintained without disturbing the layout of the original image to be printed.

  The print control process as described above is preferably performed for all print results that are continuously printed. However, when the processing burden due to processing for all print results is large, sampling is performed at predetermined intervals from the print results that are continuously printed, and processing is performed on the sampled print result image data. You can go.

  It is also preferable to store and save the attributes of each document image data in the document image database. The attributes of document image data include a file name, a file size, an identifier of an application for processing document image data, an order number for printing, and the like. By storing these attributes, it is possible to easily specify the document image data and the history data of the feature amount based on the file name and the order number for processing. Further, in addition to the correction condition setting process, a process for changing the document image data itself and a charge process for a print order can be performed together.

  In addition, when performing book printing by sequentially repeating a plurality of document image data, the feature amount of the region of interest is extracted from the print result image data based on the same document image data acquired for each number of sheets to be registered, and the correction condition Can be registered as history data in the feature amount history database.

  In addition, the said embodiment is an example of this invention and is not limited to this. For example, in the above embodiment, the print control apparatus 100, the image forming apparatus 200, and the inspection apparatus 300 have been described as separate apparatuses. However, any two or more apparatuses may be combined to form a single apparatus. In that case, information can be exchanged not via the network but via the data bus inside the apparatus.

1 is a diagram showing a configuration of an image forming system in an embodiment of the present invention. 1 is a block diagram illustrating a configuration of a print control apparatus according to an embodiment of the present invention. It is a figure which shows the flowchart of the printing control method in embodiment of this invention. It is a figure which shows the example of registration of the original image database in embodiment of this invention. It is a figure which shows the example of registration of the attention area database in embodiment of this invention. It is a figure which shows the example of a standard look-up table (LUT). It is a figure which shows the example of a look-up table (LUT). It is a figure which shows the example of registration of the feature-value log | history database in embodiment of this invention. It is a figure which shows the example of the gradation reproducibility curve for demonstrating a gradation correction process. It is a figure explaining the registration or update of the feature-value log | history database in embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Control part, 12 Memory | storage part, 14 Data interface, 16 Input / output part, 100 Print control apparatus, 200 Image forming apparatus, 201 Control part, 202 Original image data acquisition means, 203 Paper feed means, 204 Printing means, 205 Paper discharge Means, 206 data interface, 222 platen, 224 scanner, 230 paper stocker, 232 paper transport belt, 240 charging unit, 241 exposure unit, 242 developing unit, 243 photoconductor, 244 transfer unit, 245 fixing unit, 250 paper discharge stocker, 300 Inspection device, 301 Image reading means, 302 Data interface.

Claims (18)

A feature amount acquisition means for acquiring a feature amount extracted from a print result image formed on a print medium based on document image data;
Storage means for associating the feature quantity acquired by the feature quantity acquisition means with the document image data and holding it as a feature quantity history database;
A printing control apparatus comprising: The print control apparatus according to claim 1,
History data extraction means for extracting, as history data, feature quantities stored in association with the document image data from the feature quantity history database;
Correction condition setting means for setting correction conditions for image formation of the document image data based on the feature quantity acquired by the feature quantity acquisition means and the history data extracted by the history data extraction means;
A printing control apparatus comprising: The print control apparatus according to claim 2,
The correction condition setting unit calculates a difference between the feature amount acquired by the feature amount acquisition unit and the history data extracted by the history data extraction unit, and sets the correction condition based on the difference. A printing control device. In the printing control apparatus according to any one of claims 1 to 3,
The printing control apparatus, wherein the storage unit holds the feature amount acquired by the feature amount acquisition unit and the attribute of the document image data in association with each other. In the printing control apparatus according to any one of claims 1 to 4,
The print control apparatus, wherein the feature amount acquisition unit acquires a feature amount extracted from a region of interest predetermined for each document image data. In the printing control apparatus according to any one of claims 1 to 5,
The print control apparatus, wherein the feature amount is a gradation of an image. A feature amount acquisition step of acquiring a feature amount extracted from a print result image formed on a print medium based on document image data;
A history data registration step of associating the feature amount acquired in the feature amount acquisition step with the document image data and holding it as a feature amount history database;
A printing control method comprising: The printing control method according to claim 7,
A history data extraction step for extracting, as history data, feature quantities stored in association with the document image data from the feature quantity history database;
A correction condition setting step for setting a correction condition for image formation of the document image data based on the feature amount acquired in the feature amount acquisition step and the feature amount extracted in the history data extraction step;
A printing control method comprising: The printing control method according to claim 8,
In the correction condition setting step, a difference between the feature amount acquired in the feature amount acquisition step and the feature amount extracted in the history data extraction step is calculated, and the correction condition is set based on the difference. A printing control method. In the printing control method according to any one of claims 7 to 9,
In the history data registering step, the feature amount acquired in the feature amount acquiring step and the attribute of the document image data are stored in association with each other. In the printing control method according to any one of claims 7 to 10,
The print control method characterized in that the feature amount acquisition step acquires a feature amount extracted from a region of interest predetermined for each document image data. In the printing control method according to any one of claims 7 to 11,
The print control method, wherein the feature amount is a gradation of an image. A computer having storage means;
A feature amount acquisition means for acquiring a feature amount extracted from a print result image formed on a print medium based on document image data;
History data registration means for causing the storage means to associate the feature quantity acquired by the feature quantity acquisition means with the document image data and hold it as a feature quantity history database;
A print control program that functions as a print control apparatus including The print control program according to claim 13.
The computer,
History data extraction means for extracting, as history data, feature quantities stored in association with the document image data from the feature quantity history database;
Correction condition setting means for setting correction conditions for image formation of the document image data based on the feature quantity acquired by the feature quantity acquisition means and the history data extracted by the history data extraction means;
A print control program that functions as a print control apparatus including The print control program according to claim 14,
The correction condition setting unit calculates a difference between the feature amount acquired by the feature amount acquisition unit and the history data extracted by the history data extraction unit, and causes the correction condition to be set based on the difference. Characteristic print control program. In the printing control program according to any one of claims 13 to 15,
A printing control program that causes the storage unit to store the feature amount acquired by the feature amount acquisition unit and the attribute of the document image data in association with each other. The print control program according to any one of claims 13 to 16,
The print control program according to claim 1, wherein the feature amount acquisition unit acquires a feature amount extracted from a region of interest predetermined for each document image data. The print control program according to any one of claims 13 to 17,
The print control program characterized in that the feature amount is a gradation of an image.

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