JP2018110327A - Image-processing device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate raster data for each of basic and spot color plates to make a required memory amount smaller than that required in such a method that basic color raster data subjected to color correction are merged with spot color raster data.SOLUTION: A front-end device converts print data into intermediate data, and decomposes an object in an intermediate data format into spot and basic color objects. An image-drawing data-generating unit 70 draws basic color objects in turn to write the resultant data into a buffer unit 80. When a spot color determination unit 90 senses the start of input of a spot color object, which means the drawing of all of basic color objects in a page has been finished, the image-drawing data-generating unit 70 suspends, and a color-correcting unit 92 performs color correction on image-drawing data in the buffer unit 80 at that point of time. After the completion of color correction, the image-drawing data-generating unit 70 draws the spot color object, and merges the result of the drawing with the image-drawing data subjected to color correction in the buffer unit 80.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an image processing apparatus and a program.

  In the system disclosed in Patent Document 1, the object color separation unit is configured such that an intermediate data object input in the drawing order is an individual color with the same shape and a basic color object having the same shape as the object and the basic color object. The basic color object is output and the special color object is stored in the special color plane spool. At this time, the shape of the existing spot color object in the spot color spool is changed to a shape excluding a portion hidden by the spot color object to be stored. Each time the object color separation unit finishes processing all the objects for one page, the objects in each special color plate spool are output while simulating the special color components with basic colors according to the order of overlap of each special color plate in printing. To do.

  In the system disclosed in Patent Literature 2, the intermediate data generation unit generates intermediate data including color information of each image data based on the color image data received by the receiving unit. The spot color image data is extracted from the intermediate data by the spot color image data extraction unit, and the color information of the extracted spot color image data is converted into color information expressed by the process color by the color information conversion unit. The transmittance information adding unit adds the transmittance information to the color information of the converted spot color image data. The drawing processing unit adds the colors of the two image data based on the transmittance information and color information of the spot color image data determined by the overlap determination unit as having the back image data, and the color information of the back image data. The drawing process is performed as follows.

  The apparatus disclosed in Patent Literature 3 performs color separation processing and RIP processing for each page, generates raster data for each color of CMYK and raster data corresponding to a spot color name, and then specifies a CMYK value specified by the spot color name. Based on the above, the raster data of the spot color is synthesized with the raster data of each color of CMYK and output. As a result, the overprint of the object specified with the spot color is accurately reproduced.

  In Patent Document 4, a flag value indicating whether each pixel has a spot color (that is, a process color) is recorded in control plate data called a tag plate, and tone adjustment or the like is performed on a color value of a pixel that is not a spot color. A control is disclosed in which color correction is performed and color values of the spot color pixels are not corrected.

JP 2015-188212 A Japanese Patent Laying-Open No. 2015-026933 JP 2004-148535 A JP 2009-267927 A

  By creating control information that indicates whether each pixel is a spot color and performing color correction only on pixels that are not spot colors with reference to this control information, color reproduction is performed for the portion where the spot color is overprinted to the basic color of the background Is not correct. This is because the pixels on which the spot color is overprinted are recorded as the spot color pixels in the control information, so that the color correction is not performed on the base basic color.

  On the other hand, in the method of generating raster data for each basic color plate and spot color plate, and combining the raster data for the special color plate with the raster data for the basic color plate, color correction is applied to the raster data for the basic color plate, By combining the raster data of the special color plate, it is possible to accurately reproduce the color of the special color overprint. However, a computer that executes this type of processing requires a storage capacity for storing both raster data for the basic color plate and raster data for the special color plate.

  The present invention generates raster data for each base color and spot color plate, and reduces the amount of memory required compared to a method for combining spot color raster data with color-corrected basic color raster data. The purpose is to reduce.

  According to a first aspect of the present invention, there is provided means for dividing image element data in an intermediate data format in an output unit into spot color element data and non-spot color element data, and the input non-spot color element data group and the spot color element data group. The drawing means for generating drawing data in the buffer by drawing in the buffer, the color correction means for performing color correction on the color correction target portion of the drawing data in the buffer, and the drawing means After drawing for all the non-spot color element data in the output unit, before starting to draw the spot color element data in the output unit, the color for the drawing data in the buffer at that time The correction unit performs color correction, and after the color correction is completed, the drawing unit performs control to draw the spot color element data with respect to the color-corrected drawing data in the buffer. And control means, an image processing apparatus having a.

  According to a second aspect of the present invention, the drawing means generates, in the buffer, drawing data having a data format in which the data amount of the area is smaller between the bitmap format and the compression format for each area in the output unit. The image processing apparatus according to claim 1, wherein:

  The invention according to claim 3 is the image processing apparatus according to claim 2, wherein the compression format is a run-length type.

  The invention according to claim 4 is characterized in that the dividing means accumulates the non-spot color element data group derived from the image element data group in the output unit in a first buffer, and the image data element group in the output unit. The spot color element data group derived from the above is stored in a second buffer, and the image processing apparatus further stores all the non-spot color element data groups in the output unit stored in the first buffer in the drawing unit. Supplying superimposition information to be applied to the non-spot color element data group stored in the second buffer and then to the drawing means, and then the non-spot color element data stored in the second buffer Supply means for supplying a group to the drawing means, and the control means temporarily stops the operation of the drawing means when the overlay information is supplied to the drawing means. Causing the color correction unit to perform color correction on the drawing data, and after completion of the color correction, restarting the operation of the drawing unit to process the spot color element data group supplied from the supply unit. The image processing apparatus according to claim 1, wherein the image processing apparatus is an image processing apparatus.

  The invention according to claim 5 further includes means for generating information indicating a region of non-spot color element data using a color expression other than device CMYK in the drawing data in the buffer, and the control means includes The area indicated as an area of non-spot color element data using color expression other than the device CMYK as information is handled as not corresponding to the color correction target part. The image processing apparatus described in the above.

  According to a sixth aspect of the invention, a spot color element data and a non-spot color element data in an intermediate data format within an output unit are input to the computer, and the non-spot color element data group and the spot color element data group are drawn in a buffer. A drawing unit that generates drawing data in the buffer; a color correction unit that performs color correction on a color correction target portion of the drawing data in the buffer; and the drawing unit includes all of the output units in the output unit. After drawing the non-spot color element data, before starting drawing the spot color element data in the output unit, the color correction unit performs color correction on the drawing data in the buffer at that time. Control means for controlling the drawing means to draw the spot color element data for the color-corrected drawing data in the buffer after completion of the color correction. Is a program for causing the performance.

  According to the invention according to claim 1 or 6, compared to a method of generating raster data for each base color and spot color plate and combining the raster data of the spot color with the raster data of the base color subjected to color correction. The amount of memory required can be reduced.

  According to the second aspect of the present invention, it is possible to reduce the data amount of the drawing data as compared with the method in which the entire area is either the bitmap format or the compression format.

  According to the third aspect of the present invention, the load of color correction by the color correction unit can be reduced as compared with the case where the entire area is in the bitmap format, and the data amount of the drawing data is greater than in the case where the entire area is in the run length format. Can be reduced.

  According to the fourth aspect of the present invention, the process of drawing the last non-spot color element data in the output unit is lower than the method of examining the color information included in each of the non-spot color element data and the spot color element data. Can be detected by load.

  According to the fifth aspect of the present invention, it is possible to accurately perform color reproduction of non-spot color element data that is not applicable to the color correction of the color correction unit in addition to the spot color.

It is a block diagram which shows the example of a structure of an image processing system. It is a figure which shows the example of a function structure of the front end apparatus with which a printing control system is provided, and a back end apparatus. It is a figure which shows the specific example of the transition of the memory content of a spot color spool. It is a figure which shows an example of the process sequence of a spot color smoothing part. It is a figure for demonstrating the specific example of the process of a spot color smoothing part. It is a figure which shows an example of an internal structure of a drawing part. It is a figure which shows an example of the process sequence of a drawing part. It is a figure for demonstrating the specific example of a process of a drawing part. It is a figure which shows an example of a structure of the buffer part in a drawing part.

<System configuration of the embodiment>
FIG. 1 is a block diagram illustrating an example of the configuration of an image processing system. The system in the example of FIG. 1 includes a terminal device 10, a print control system 20, and a printing device 50. The print control system 20 includes a front end device 30 and a back end device 40. The terminal device 10 is connected to the front-end device 30 via the communication unit 60 and transmits a print job including a document print command to the front-end device 30 in accordance with a user instruction. The front-end device 30 is connected to the back-end device 40 via the communication unit 62, and the back-end device 40 is connected to the printing device 50 via the communication unit 64.

  The communication means 60, 62, 64 may be a data communication network such as a LAN (Local Area Network), for example. The communication means 60, 62, and 64 may be communication means common to each other or may be different communication means. For example, a LAN is used as the communication means 60 between the terminal device 10 and the front-end device 30, and the communication means 62 between the front-end device 30 and the back-end device 40 and between the back-end device 40 and the printing device 50. As the communication means 64, dedicated communication means different from the LAN may be used.

  In the system of the example of FIG. 1, the print job transmitted from the terminal device 10 is processed by the front end device 30. The processing result data is transferred to the back-end device 40, and printing is performed by the printing device 50 in accordance with the image data generated in the back-end device 40. The image data in this embodiment indicates data that represents an image to be printed in a data format (for example, raster format or run-length format) that can be handled by the printing apparatus 50.

  The terminal device 10, the front-end device 30, and the back-end device 40 in the example of FIG. 1 can be realized by a general-purpose computer, for example. The computer has a circuit configuration in which a CPU (central processing unit), a memory (primary storage), various I / O (input / output) interfaces, a communication interface, and the like are connected via a bus as hardware. The computer exchanges data with other devices via the communication interface. Further, an input device such as a keyboard and a mouse and a display device such as a liquid crystal display may be connected to the bus via, for example, an I / O interface. Also, a secondary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive) is connected to the bus via an I / O interface. Further, a disk drive for reading portable non-volatile recording media of various standards such as DVD and flash memory may be connected. Such a drive functions as an external storage device for the memory. A program in which the processing content of each embodiment described below is described is stored in a secondary storage device such as an HDD via a recording medium such as a CD or DVD or via a network, and is installed in a computer. The program stored in the secondary storage device is read into the memory and executed by the CPU, whereby the processing of the embodiment described later is realized.

  In the example of each embodiment to be described later, some of the functions of the back-end device 40 may be realized by hardware processing instead of software processing by executing a program. For the hardware processing, for example, an integrated circuit such as ASIC (Application Specific Integrated Circuit) is used. Further, for example, a processor called a dynamically reconfigurable processor (DRP) capable of dynamically reconfiguring a circuit during the execution of processing may be used. For example, hardware elements such as DRP and ASIC that execute a part of the functions of the back-end device 40 are configured in advance, and such hardware elements are connected to a general-purpose computer bus so that The end device 40 may be realized.

  As a specific example of hardware for realizing the front-end device 30 and the back-end device 40, it is conceivable to use a blade server in which a plurality of information processing devices each functioning as a server are mounted in a single casing. The blade server is a server device in which a general-purpose computer including a CPU and a memory is mounted on a single board (blade) and a plurality of blades are mounted in a housing. For example, one blade mounted on the blade server may function as the front end device 30 and the other one blade may function as the back end device 40. Alternatively, for example, each of the front-end device 30 and the back-end device 40 may be realized by a plurality of blades mounted on a blade server.

  Of course, this is only an example, and the front-end device 30 and the back-end device 40 may be constructed on separate computer devices mounted in separate housings. Further, the front-end device 30 and the back-end device 40 may be constructed on the same computer device (that is, a program for performing processing of each device is executed on the same computer).

  The printing apparatus 50 is an apparatus that performs printing on a medium such as paper. For example, the printing apparatus 50 may be a continuous paper printer or a cut paper printer. Note that the printing method of the printing apparatus 50 is not particularly limited. An electrophotographic system or an inkjet system may be used. Other methods may also be used.

  FIG. 2 shows an example of functional configurations of the front-end device 30 and the back-end device 40 included in the print control system 20. The front end device 30 includes a print job receiving unit 32, an interpreting unit 34, and a spot color smoothing unit 36. The back-end device 40 includes a first buffer 42a, a second buffer 42b, a combining unit 43, a drawing unit 44, and an output buffer 46.

  The print job receiving unit 32 of the front end device 30 receives a print job from the terminal device 10. In the example of this embodiment, the print job includes, for example, a command for printing a document and data describing a document to be printed in a page description language. A page description language (abbreviated as PDL: PDL is an abbreviation of Page Description Language) is a computer programming language for causing an information processing device to execute display display processing, printing processing, and the like. Examples of the page description language include PostScript (registered trademark) and PDF (Portable Document Format). The data described in the page description language includes position information, format information, color information, and the like of objects such as characters and figures, images (bitmap images) constituting a document to be printed. In the following description, data in which a document to be printed is described in a page description language is referred to as “PDL data”. The print job reception unit 32 passes PDL data included in the received print job to the interpretation unit 34.

  The interpretation unit 34 interprets the PDL data acquired from the print job reception unit 32, and generates and outputs intermediate data including a command representing a procedure for generating an image to be printed according to the interpretation result. The PDL data is finally converted into image data representing an image to be printed, and this image data is used for printing on a sheet by the printing apparatus 50. The image data is data that represents an image to be printed in a format that can be handled by the printing apparatus 50. For example, data in a raster format (that is, a bitmap format) is an example. The intermediate data is data having an intermediate granularity between the PDL data and the image data. The intermediate data format is, for example, a representation of an image object described in PDL that is further subdivided into simple elements of minute elements. Various intermediate data formats are known, such as a display list format and a format disclosed in Patent Document 1.

  The interpretation unit 34 interprets the PDL data to decompose each object represented by the PDL data into unit shapes used in the intermediate data format (for example, a rectangular format, a run format, and a raster format). The data representing the shape and color (this represents the object in the intermediate data format) is generated. The interpreter 34 separates the generated object in the intermediate data format into a basic color object made up of only basic color components and a spot color object made up of only spot color components. Here, the basic color is a primary color (for example, four colors of C, M, Y, and K) used for printing, and is also called a process color. The basic color object and the spot color object obtained by the separation differ only in the item of color data indicating the color of the object, and the other data items take over the data of the object before the separation. The basic color object has only the value of each basic color component (for example, C, M, Y, K) as color data, and the special color object is, for example, a combination of the name of the special color (special color name) and its density as color data. Or only the spot color name. The interpretation unit 34 sequentially outputs the basic color objects obtained by the separation of the objects to the first buffer 42 a of the back-end device 40, and sequentially outputs the spot color objects to the spot color smoothing unit 36.

  The spot color smoothing unit 36 flattens the spot color objects in the intermediate data format output in order from the interpretation unit 34 while maintaining the intermediate data format. Also, a spot color simulation is performed for converting the spot color of the smoothed spot color object into an expression in the basic color of the printing apparatus 50. At the time of smoothing, the spot color smoothing unit 36 makes the color of the portion where the objects having the same spot color component overlap each other become the color of the spot color component itself (not the color where the spot color components overlap). Next, eclipse processing is performed. The eclipse process is performed using the spot color spool 38. The spot color spool 38 is a spool that stores a spot color object group in an intermediate data format in association with each other in the order of input. The eclipse process will be described in detail later. The spot color smoothing unit 36 sequentially outputs each object of the eclipse processing result to the second buffer 42b of the back-end device 40.

  In the back-end device 40, the first buffer 42a stores the basic color objects output in order from the interpretation unit 34 in association with the order. Further, the second buffer 42b stores the spot color objects output in order from the spot color smoothing unit 36 (however, converted to the basic color expression at this time) in association with the order. The object group stored in the first buffer 42a and the second buffer 42b is of an intermediate data format. The combining unit 43 combines the intermediate data stored in the first buffer 42 a and the second buffer 42 b and supplies the combined data to the drawing unit 44. That is, as a combining process, the combining unit 43 first supplies the intermediate data of the object group of the output unit stored in the first buffer 42a to the drawing unit 44 for each output unit, and then stores the intermediate data in the second buffer 42b. Intermediate data of an output unit object group is supplied to the drawing unit 44. This order corresponds to a plate order in which the images of the special color plates are superimposed on the images of the basic color plates in the traditional printing process. The output unit is a unit indicating a range of image data output to the printing apparatus 50 by the back-end device 40 for each output process. Output page, band (one divided area when the page is divided into a plurality of parts in the sub-scanning direction), tile (one divided area when the page is divided into a plurality of parts in both the main scanning direction and the sub-scanning direction), etc. It is an example of a unit. The drawing unit 44 generates drawing data of one output unit in a built-in buffer, converts the drawing data into image data, and outputs the image data to the printing apparatus 50.

  The drawing unit 44 draws intermediate data of each object sequentially input from the combining unit 43 to finally generate image data of the output unit, and writes the generated image data in the output buffer 46. Here, the drawing unit 44 may directly convert the intermediate data into image data, but as another example, the intermediate data is once converted into drawing data and stored in the buffer, and finally the drawing data in the output unit is converted into image data. May be output after being converted to. The data format of the drawing data is a data format closer to the image data than the intermediate data, but is at least partially different from the image data. For example, the case where the image data is in the raster format and the drawing data is in the run-length format corresponds to this example.

  For each output unit such as a page, first, a basic color object group in the output unit is sequentially input from the combining unit 43 to the drawing unit 44, and then a spot color object group is input. In this object input flow, the drawing unit 44 completes drawing of all the basic color objects in the output unit and then starts drawing the first spot color object in the output unit. Color correction is performed on the generated drawing data or image data. This color correction is a correction for reproducing the color in the color space of the PDL data in the color space (device-dependent color space) of the printing apparatus 50. For the spot color object, when the spot color smoothing unit 36 converts the spot color into the basic color expression, conversion reflecting the characteristics of the color space of the printing apparatus 50 is performed, so that color correction is unnecessary. Then, after this color correction is completed, the drawing unit 44 sequentially draws and combines the spot color objects in the output unit with respect to the color corrected drawing data / image data.

  The image data for each output unit generated by the drawing unit 44 is stored in the output buffer 46 and sequentially read from the printing apparatus 50. The printing apparatus 50 prints the image data of each output unit read from the output buffer 46 on a sheet.

  Next, the process performed by the spot color smoothing unit 36 will be described using a specific example with reference to FIG. In the upper part of FIG. 3, three spot color objects 102b (intermediate data) of spot colors (green in the illustrated example) in the same output unit (for example, page 100) sequentially input from the interpreter 34 to the spot color smoother 36 are displayed. It is shown with numbers 1-3 indicating the generation order. The lower part of FIG. 3 shows the state of the object group in the spot color spool 38 when the upper spot color object 102b is stored. The frame of the page 100 is reference information for representing the position of the spot color object 102b in the page.

  First, the first spot color object is a spot color object having a value of G (green) = 0. Such a spot color object having a spot color component value of 0 is generated from the knockout designated object. At this point, since there is no spot color object in the spot color spool 38 for the G plate, the eclipse process is not performed. Also, the spot color object with the value of “0” for the spot color component is for eclipse the spot color object whose drawing order is earlier than that object to produce a knockout effect. The drawing itself is not necessary. Therefore, the first spot color object is not stored in the spot color spool 38. The spot color object generated second has color data of G = 0.01. Even at this time, since there is no spot color object in the spot color spool 38, the eclipse process is not performed. The second spot color object is stored in the spot color spool 38 and becomes the first spot color object in the spot color spool 38. The third spot color object partially overlaps the first spot color object in the spot color spool 38 (second in the input order). Accordingly, the shape of the first spot color object in the spot color spool 38 is changed (eclipse) to a shape excluding a portion overlapping the third spot color object in the input order. The third spot color object is stored in the spot color spool 38 and becomes the second object in the spot color spool 38. When the third spot color object is the last object in the drawing order on the page 100, an object (in this example) that is inside the spot color spool 38 when the above processing for the third spot color object is completed. Then, two objects) are output to the back-end device 40. For details of the eclipse process, refer to Patent Document 1, for example.

  FIG. 4 shows an example of the processing procedure of the spot color smoothing unit 36. In this procedure, first, the spot color smoothing unit 36 receives a spot color object from the interpretation unit 34 (S30), and performs eclipse processing on each object in the spot color spool 38 with the received spot color object (S32). When eclipse is completed for all objects in the spot color spool 38, the received spot color object is stored in the spot color spool 38 (S34). The above processes of S30 to S34 are repeated for all objects in the output unit such as a page (S36).

  When the processing for all the objects in the output unit is completed (the determination result in S36 is Yes), spot color object groups that do not overlap with each other are stored in the spot color spool 38 at that time. That is, the smoothing of the spot color object group in the output unit is completed. Thereafter, the spot color smoothing unit 36 converts the color data of each spot color object in the spot color spool 38 from the spot color representation to the basic color representation (S38). Then, the spot color smoothing unit 36 outputs instruction data for setting the overlay information to the second buffer 42b (S40), and then outputs each spot color object in the spot color spool 38 to the second buffer 42b. (S42). Then, the instruction data for resetting the overlay information is output to the second buffer 42b (S44).

  The overlay information is information that defines how to obtain the color value (pixel value) of the overlay result when the spot color plate is superimposed on the background image (in this example, the image consisting of the basic color object group). is there. For example, the above-described transmittance, overprint designation information, and the like are examples of overlay information. In addition, when the result obtained by adding together the pixel values of the same basic color of the upper plate and the background image exceeds the upper limit of the pixel value (for example, 255 for 8 bits), the overlay information indicates the value of the pixel. It may be information defining how to decide (and how to adjust the values of other pixels accordingly). The superimposition information is information that is specified in the original PDL data in document units, page units, or object units, and is inherited by the entire intermediate data document, page, or object (the intermediate data object is In general, PDL objects are interpreted and further divided). The instruction data for setting the superposition information and the instruction data for resetting are stored as one of the intermediate data in the second buffer 42b in association with the output order in the same manner as the intermediate data of the other spot color objects. . The superposition information is applied to the spot color object group between the instruction data for setting it and the instruction data for resetting (this application is performed by the drawing unit 44 of the back-end device 40). .

  A specific example of processing according to the procedure of FIG. 4 will be described with reference to FIG.

  Assume that four objects 102A to 102D shown on the left side of FIG. 4 are input to the spot color smoothing unit 36 in order from the top. In this example, it is assumed that the objects 102A and 102B are knocked out and the objects 102C and 102D are overprinted. In this example, it is assumed that there is only one special color (indicated as “Spot” in the figure).

In the example of FIG. 4, the color (C, M, Y, K, Spot) of the object 102A is (1, 0, 1).
, 0, 0) and the color of the object 102B is (0, 0, 1, 0, 0.01). The color of the object 102C is (1, NA, NA, NA, NA), and the color of the object 102D is (NA, NA, NA, NA, 0.01). Here, NA indicates that the value of the component does not exist. In the case of overprinting, if the density of a certain color component of an object is 0, the background color of that color component is transmitted as it is, so that this color component is treated as “not present” (NA). Is called.

  In this case, in the procedure of FIG. 4, first, the first input object 102A is a basic color object of (C, M, Y, K) = (1, 0, 1, 0) and a spot color of Spot = 0. Is broken down into objects. Of these, the basic color object is output to the first buffer 42 a of the back-end device 40. This is the first basic color object in the “output intermediate data” column at the right end of the figure. On the other hand, the spot color object of Spot = 0 is used for eclipse processing of the object in the spot color spool 38, but here, the value of the spot color component is “0”, so it is not stored in the spot color spool 38.

  Next, the second input object 102B is decomposed into a basic color object of (C, M, Y, K) = (0, 0, 1, 0) and a spot color object of Spot = 0.01. The Among them, the basic color object is output to the back-end device 40 (second in the “output intermediate data” column). The spot color object with Spot = 0.01 is stored in the spot color spool 38.

  Next, the third input object 102C is decomposed into a basic color object of (C, M, Y, K) = (1, NA, NA, NA) and a spot color object of Spot = NA. Since the value of the spot color object is NA (does not exist), it is not used for eclipse processing and is not stored in the spot color spool 38. The basic color object is output to the first buffer 42a.

  Finally, the fourth input object 102D is decomposed into a basic color object with (C, M, Y, K) = (NA, NA, NA, NA) and a spot color object with Spot = 0.01. The Of these, the basic color object has the same basic color component as NA, since all the basic color components are NA. Therefore, the basic color object is not sent to the first buffer 42a. On the other hand, the spot color object of Spot = 0.01 is eclipseed the spot color object in the spot color spool 38 and stored in the spot color spool 38.

  The transition of the stored contents of the spot color spool 38 in the above example is the same as that illustrated in FIG. 4 (the spot color object is not generated from the object 102C and is omitted in FIG. 4).

  When the above processing is finished, the spot color spool 38 stores spot color objects 102E and 102F. When the output of the basic color object for the fourth input object 102D and the processing related to the special color spool 38 are finished, the special color objects 102E and 102F in the special color spool 38 are color-converted into the basic color expression. Then, the overlay information (set), the color-converted spot color object 102E, the color-converted spot color object 102F, and the overlay information (reset) are output to the second buffer 42b in this order.

  In the back-end device 40, when all the basic color objects and spot color objects derived from one output unit have been accumulated in the first buffer 42a and the second buffer 42b, the combining unit 43 displays the intermediate data in the drawing unit 44. Output to. In this output, the combining unit 43 first supplies the object groups in the first buffer 42a to the drawing unit 44 in order, and when it finishes, supplies the object groups in the second buffer 42b to the drawing unit 44 in order.

  Next, an example of the internal configuration of the drawing unit 44 of the back-end device 40 will be described with reference to FIG.

  The drawing unit 44 includes a drawing data generation unit 70, a buffer unit 80, a spot color determination unit 90, and a color correction unit 92. The drawing unit 44 may include a data conversion unit 94.

  The drawing data generation unit 70 generates drawing data from the intermediate data of each object that is input in order.

  In one example, the drawing data is data in the same data format as the image data, that is, data in a data format that can be handled by the printing apparatus 50 that represents the image to be printed. In this case, the drawing unit 44 may not include the data conversion unit 94. This example corresponds to the case where both the drawing data and the image data are in the same raster format, or the case where both are in the same run-length format.

  In another example, the drawing data has a data format closer to the image data than the intermediate data, but may be data having a data format that is at least partially different from the image data. For example, this is the case when the image data format that can be handled by the printing apparatus 50 is a raster format, whereas the drawing data is a run-length format. In this case, the data conversion unit 94 performs processing for converting the drawing data into the data format of the image data. For example, the process of converting run-length format data to raster format can be executed at high speed by a hardware circuit. This example also applies when the image data is in either raster format or run-length format, whereas the drawing data is data in which the raster format and run-length format are mixed (detailed examples will be described later). Applicable. The data converter 94 converts a portion of the drawing data of this type having a data format different from that of the image data into the data format of the image data.

  The buffer unit 80 stores the drawing data generated by the drawing data generation unit 70. This accumulation is performed for each output unit (for example, page). That is, until the drawing data generated from all the objects included in one output unit (this includes both the data for the basic color object and the data for the spot color object) has been accumulated, The drawing data input from the drawing data generation unit 70 is stored in order. When the storage of all the drawing data derived from one output unit is completed, the buffer unit 80 outputs the drawing data.

  The spot color determination unit 90 monitors intermediate data sequentially input from the combining unit 43. When it is detected that the input of the spot color object is started by this monitoring, the spot color determination unit 90 temporarily stops the generation of the drawing data from the intermediate data (or the output of the generated drawing data) to the drawing data generation unit 70. Instructing the color correction unit 92 to execute color correction. For example, the spot color determination unit 90 may determine that the input of the spot color object is started when instruction data for setting the superposition information is detected from the intermediate data output in the rank from the combination unit 43. . However, this is only an example. Instead, for example, the spot color determination unit 90 checks the color data of the intermediate data of the objects output in order from the combining unit 43, and when the first object whose color data indicates the spot color is detected, the spot color object is input. You may determine with having started.

  Receiving the pause instruction from the spot color determining unit 90, the drawing data generating unit 70 pauses the operation before outputting the spot color object whose output order in the output unit is the first to the buffer unit 80. At the time when this pause instruction arrives, generation of drawing data and output to the buffer unit 80 for the basic object group of the output unit has already been completed. Therefore, at this time, the buffer unit 80 is in a state where drawing data groups generated from all basic color object groups in the output unit are accumulated. At this time, the color correction unit 92 that has received a color correction instruction from the spot color determination unit 90 performs color correction on the drawing data stored in the buffer unit 80. This color correction is a correction for reproducing in the color space of the printing apparatus 50 the same color as the color in the color space of the PDL data. The color correction unit 92 writes the color corrected drawing data back to the buffer unit 80. As a result, the drawing data before color correction which has been in the buffer unit 80 until then is replaced with drawing data after color correction.

  After the replacement is completed, the color correction unit 92 instructs the drawing data generation unit 70 to resume drawing data output. At the time of this instruction, the buffer unit 80 stores drawing data generated from all basic color objects in the output unit and subjected to color correction. When the drawing data generation unit 70 resumes the operation in response to the instruction, the intermediate data of the spot color object in the output unit is sequentially converted into drawing data and written to the buffer unit 80.

  When the drawing data for all the objects in the output unit is written in the buffer unit 80 in this way, the buffer unit 80 outputs the finally held drawing data to the subsequent stage. When the drawing data has the same data format as the image data that can be handled by the printing apparatus 50, there is no data conversion section 94 after the buffer section 80, and the drawing data in the buffer section 80, that is, the image data is stored in the printing apparatus 50. Supplied. When the drawing data has a data format different from the image data that can be handled by the printing apparatus 50 (or includes a portion having a different data format), the drawing data in the buffer unit 80 is converted into image data by the data conversion unit 94, Supplied to the printing device 50.

  Next, an example of a processing procedure executed by the drawing unit 44 will be described with reference to FIG. The procedure in FIG. 7 is executed for each output unit.

  In this procedure, when the next intermediate data is input from the combining unit 43 to the drawing unit 44 (S50), the data indicates data indicating the start of the spot color object (for example, data for instructing the above-described overlay information set). ) Is determined by the spot color determination unit 90 (S52). If the result of this determination is No, the data is intermediate data of the object to be drawn. In this case, the drawing data generation unit 70 converts the intermediate data of the object into drawing data, and writes the obtained drawing data in the buffer unit 80 (S54). Then, it is determined whether or not the object is the last object of the output unit (S56). If the determination result is No, the process returns to S50 to receive the next intermediate data input from the combining unit 43.

  When the determination result in S52 is Yes (that is, input of the spot color object group is started), the spot color determination unit 90 instructs the drawing data generation unit 70 to pause (S58). In response to this instruction, the drawing data generation unit 70 temporarily performs drawing processing (or at least output of drawing data to the buffer unit 80) before outputting the drawing data of the first spot color object in the output unit to the buffer unit 80. Stop. Thereafter, the drawing data generation unit 70 does not output the drawing data of the object to the buffer unit 80 until a restart instruction is issued. Therefore, at the time when the instruction to pause is given, the buffer unit 80 holds drawing data derived from the basic color object group of the output unit, and the information of the spot color object is reflected in the drawing data. Not.

  Further, the spot color determining unit 90 instructs the color correcting unit 92 to perform color correction on the drawing data in the buffer unit 80 (S60). In response to this instruction, the color correction unit 92 performs color correction for matching the drawing data derived from the basic color object group in the buffer unit 80 with the color space of the printing apparatus 50. The drawing data subjected to the color correction is written back to the buffer unit 80.

  When the color correction of the drawing data in the buffer unit 80 is completed (Yes in S62), the color correction unit 92 performs a drawing operation on the drawing data generation unit 70 (or outputs drawing data to the buffer unit 80). Is instructed to resume (S64). Receiving this instruction, the drawing data generation unit 70 resumes drawing processing (or output of drawing data to the buffer unit 80). Thereby, the drawing data generation unit 70 acquires from the combining unit 43 in order from the first object of the spot color object group of the output unit (S50), generates drawing data of the spot color object, and generates the generated drawing data as a buffer unit. It is combined with the drawing data in 80 (S54). The processes of S50, S54, and S56 are repeated until the final spot color object drawing process of the output unit is completed. When the drawing of the last spot color object is completed, the drawing data generation unit 70 ends the drawing process. Thereafter, the drawing unit 44 converts the drawing data of the final drawing result of the output unit held in the buffer unit 80 into image data by the data conversion unit 94, and outputs the image data to the printing apparatus 50. To do. When the drawing data has the same data format as the image data, the drawing unit 44 outputs the final drawing data formed in the buffer unit 80 to the printing apparatus 50 as it is.

  A specific example of the processing of the drawing unit 44 described above will be described with reference to FIG. FIG. 8 shows an example in which the drawing data of the five objects 1 to 5 displayed at the right end of FIG.

  (1) When drawing of the basic color objects 1 to 3 shown in FIG. 5 is finished, drawing data 200 is stored in the buffer unit 80 (drawing data is schematically shown as an image in the figure for the sake of clarity). Is held. The drawing data 200 includes basic color objects 2 and 3 in order on an area 202 where the color corresponding to the basic color object 1 is (C, M, Y, K) = (1, 0, 1, 0). It is a thing that overlapped. The color of the region 204 corresponding to the basic color objects 2 and 3 in the drawing data 200 is the same color (C, M, Y, K) as the basic color object 1 = (1, 0, 1, 0).

  (2) In the example of FIG. 5, since the basic color objects are 1 to 3, when the drawing is completed and the drawing data 200 is formed in the buffer unit 80, the drawing data generation unit 70 is temporarily stopped. The color correction unit 92 performs color correction on each basic color component of the drawing data 200. As a result, the colors of the areas 202 and 204 of the drawing data 200 are both (C, M, Y, K) = (0.9, 0.1, 0.9, 0).

  (3) When the color correction is completed, the drawing results of the spot color objects 4 and 5 are sequentially combined with the color-corrected drawing data in the buffer unit 80. The colors of the spot color objects 4 and 5 (that is, the spot color objects 102E and 102F in FIG. 5) are (C, M, Y, K) = (0, 0, 0, 0.01) in the basic color representation. The color of the rectangular (square) area 214 of the combined rendering data 210 is the color correction result (0.9, 0.1, 0.9, 0) of the area 204 and the colors of the basic color objects 4 and 5 ( (0, 0, 0, 0.01) is synthesized (0.9, 0.1, 0.9, 0.01). The color of the region 212 where the spot color object does not overlap remains (0.9, 0.1, 0.9, 0), and the color of the region 216 containing only the spot color object is (0, 0, 0, 0.01). It becomes.

  As described above, in the present embodiment, the front-end device 30 divides the output unit intermediate data into basic color objects and spot color objects and outputs them to separate buffers (first buffer 42 a and second buffer 42 b). Then, when the back-end device 40 first draws intermediate data of all the basic color objects in the first buffer 42a in the buffer unit 80, before the drawing of the spot color object group in the second buffer 42b, The color correction unit 92 performs color correction on the drawing data in the unit 80. As a result, the colors of the basic color object group are correctly reproduced by the printing apparatus 50. Then, the drawing result of the spot color object group is synthesized with the drawing data after the color correction. Therefore, in the present embodiment, the color reproduction of the portion where the spot color overlaps the basic color in the original PDL data is correct.

  In addition, the system of the present embodiment separately holds basic color object data and spot color object data in the intermediate data stage, but in the drawing data stage, the basic color object group is drawn in the buffer unit 80 for color correction. After that, the spot color object group is combined with the color corrected drawing data in the same buffer unit 80. Therefore, it is not necessary to prepare a storage area (such as a page buffer) for a special color separately from the basic color at the stage of drawing data having a data amount much larger than that of the intermediate data. Alleviated.

  Next, an example of the internal configuration of the buffer unit 80 of the drawing unit 44 of the back-end device 40 will be described with reference to FIG.

  In the example of FIG. 9, the buffer unit 80 includes a buffer format determination unit 82, a bitmap format output unit 84a, a run length format output unit 84b, and line buffers 86-0 to 86-n for each line (n is a positive integer). including.

  The line buffers 86-0 to 86-n are provided for each line (main scanning line) of an image to be printed, and hold drawing data of the line. In this example, one output unit image is composed of (n + 1) lines from line 0 to line n. In the illustrated example, each of the line buffers 86-0 to 86-n (hereinafter collectively referred to as “line buffer 86” when there is no need to distinguish) is one of a bitmap format and a run length format. The drawing data is stored.

  The buffer format determination unit 82 determines, for each line buffer 86, whether to use the bitmap format or the run length format as the format of the drawing data stored in the line buffer 86. This determination is performed dynamically every time an input object is drawn.

  In the run length format, one run (a group of pixels having the same value) is expressed by, for example, a set of the coordinates of the start and end points of the run and the pixel value (for example, density) of the run. Regardless of the number of pixels included in the data, the data has a fixed length. For this reason, when the number of runs included in one line is small, the data length of the drawing data for one line is smaller in the run length format than in the bitmap format. However, if the number of runs in one line exceeds a certain threshold, the amount of data in the run length format exceeds that in the bitmap format.

  Therefore, as an example, in this embodiment, the buffer format determination unit 82 sets the buffer format of all lines to the run-length format at the time when drawing of the output unit is started. Then, while drawing objects to be input in order, the number of runs in the line is monitored for each line, and the buffer format is changed to the bitmap format for the line whose number of runs exceeds the threshold. .

  The buffer format determination unit 82 holds information on the buffer format of each line buffer 86. Then, when writing the drawing data of each line generated by the drawing data generation unit 70 to the corresponding line buffer 86, if the buffer format of the line is a bitmap format, the drawing result is sent to the bitmap format output unit 84a. The drawing result is passed to the run-length format output unit 84b regardless of the run-length format. The bitmap format output unit 84a writes the drawing data of the line generated by the drawing data generation unit 70 in the corresponding line buffer 86 in the bitmap format. The run-length format output unit 84b writes the drawing data of the line generated by the drawing data generation unit 70 to the corresponding line buffer 86 in the run-length format.

  Here, the format of the drawing data generated by the drawing data generation unit 70 may be a run-length format or a bitmap format. Mutual conversion between the run-length format and the bitmap format can be realized by a known digital circuit. For example, if the drawing data generation unit 70 generates drawing data in the run length format, the bitmap format output unit 84a converts the drawing data into the bitmap format and writes it in the line buffer 86, and the run length format output unit 84b writes the drawing data in the line buffer 86 in the run-length format.

  When the run-length format output unit 84 b writes a new run (run-length format drawing data) to the line buffer 86, a portion of each run held in the line buffer 86 is overlapped with the new run. May be divided by the writing, and as a result, the number of runs in the line buffer 86 may increase. For example, in a situation where there is only one run with a color value 50 in the range from x = 2 to x = 10 in the line buffer 86, a run with a color value 100 from x = 5 to x = 7 is newly written. To do. As a result of this writing, the run held in the line buffer 86 is a run of color value 50 from x = 2 to x = 5, a run of color value 100 in the range from x = 5 to x = 7, x = There are three runs of color value 50 from 7 to x = 10.

  When the number of runs in the line buffer 86 becomes equal to or greater than the threshold as a result of writing the run-length drawing data to the line buffer 86, the buffer format determination unit 82 sends the data of the line buffer 86 to the data format conversion unit 88. Directs format conversion. Upon receiving the instruction, the data format conversion unit 88 reads the drawing data (in this case, the run) from the line buffer 86, converts the data format of the read drawing data from the run length format to the bitmap format, and the conversion result. Are written back to the line buffer 86. As a result, the drawing data in the line buffer 86 is in the bitmap format. Then, the buffer format determination unit 82 stores that the data format of the line buffer 86 is a bitmap format, and thereafter passes the drawing data to be written to the line buffer 86 to the bitmap format output unit 84a.

  Further, when a new single-color image is written in the line buffer 86 holding the bitmap format drawing data by the knockout method, the pixel group belonging to the image in the line buffer 86 can be expressed by one run. As a result, even if the remaining pixels of the line buffer 86 other than the run are regarded as one run, the number of runs in the line buffer 86 is sufficiently small (that is, below the second threshold value below the above threshold value). There is a case. In this case, the amount of drawing data decreases when the drawing data in the line buffer 86 is returned to the run-length format. Therefore, the buffer type determination unit 82 has the number of runs when the drawing data newly written in the line buffer 86 is a single color and the image of the line after writing the drawing data is represented in the run length format. When it is determined that the value is equal to or smaller than the second threshold value, the data format conversion unit 88 may be instructed to convert the drawing data in the line buffer 86 into the run length format.

  In the above example, it is determined whether or not the number of runs in the line buffer 86 is equal to or greater than the threshold for the result of writing new drawing data to the line buffer 86, but new drawing data is written. This determination may be performed immediately before, and the data format conversion by the data format conversion unit 88 may be performed.

  In the example of FIG. 9, when the spot color determination unit 90 detects the start of input of the spot color object group, the drawing data generation unit 70 pauses, and the color correction unit 92 applies to the drawing data held in each line buffer 86. To correct the color. At this time, if the drawing data in the line buffer 86 is a bitmap format, the color correction unit 92 performs color correction for each pixel. On the other hand, if the drawing data in the line buffer 86 is in the run length format, color correction is performed on the color data for each run. Since the number of runs constituting one line is much smaller than the number of pixels in one line, the processing load of color correction for the drawing data in the line buffer 86 in the run length format is much larger than that in the bitmap format. Very few.

  After the color correction is completed, the drawing data generation unit 70 resumes operation, and the drawing data of the spot color object is written into each line buffer 86 that holds the drawing data after the color correction.

  As described above, the buffer unit 80 illustrated in FIG. 9 can determine the drawing data format in units of lines. The drawing data format for each line is selected from the bitmap format and the run-length format that reduces the amount of drawing data for that line. In the present embodiment, drawing data whose data format may differ for each line in the output unit is converted into image data in a single format (for example, bitmap format) by the data converter 94 and supplied to the printing apparatus 50. . However, if the printing apparatus 50 is configured to accept and process drawing data having such mixed data formats (for example, the function of the data conversion unit 94 is built in), the back-end apparatus 40 will do such a process. Drawing data in a mixed data format may be transmitted to the printing apparatus 50 via the communication unit 64. In this case, the amount of data of the mixed data format is smaller than that of the single format image data such as the bitmap format, so that the communication amount of the communication means 64 can be reduced.

  In the example of FIG. 9, the color correction performed by the color correction unit 92 may be performed on the color data of each run for the line buffer 86 having run-length format data. Since the number of runs stored in the line buffer 86 is smaller than the number of pixels in the line, the number of color data to be subjected to color correction is smaller than when color correction is performed for each pixel. For this reason, the run length line requires less time for the correction processing of the color correction unit 92 than the bitmap line. Therefore, the drawing data mixed in the data format exemplified above requires less time for color correction than the drawing data in the bitmap format as a whole. Note that the entire run-length format drawing data may require less time for color correction than the above-described mixed data format drawing data, but the amount of data may be larger than the mixed data format. high. As described above, the drawing data mixed in the data format by the method of the example of FIG. 9 is the entire drawing data in the evaluation that combines the data amount (small memory capacity) and the color correction processing load. Is better than unifying them into a bitmap format or a run length format.

  In the example of FIG. 9, the bitmap format and the run-length format can be mixed in the drawing data for each output unit. However, the format combined with the bitmap format may be a compressed data format other than the run-length format.

  In the example of FIG. 9, the drawing data format can be selected in units of lines, but the units of lines are merely an example. Instead of this, for example, a single block in which a plurality of adjacent lines are combined, a block of vertical m pixels × horizontal n pixels (m and n are positive integers), or the like may be used as a unit for selecting the drawing data format. In the case of the run length format, the data compression is only in the line direction (main scanning direction), whereas in the case of using a block as a unit for selecting the drawing data format, the data compression is also performed in the direction perpendicular to the line (sub scanning direction). Data compression is possible. For example, data compression such as thinning out or averaging one line every two lines.

  In the embodiment described above, the basic color to be subjected to color correction (that is, the basic color for which the color correction unit 92 performs color correction) is generally in the device CMYK color space. Since the device CMYK color space depends on individual devices (for example, a printing apparatus), correction according to the characteristics of the printing apparatus 50 used for output is necessary.

  Here, some of the objects included in the PDL data have color values that are neither device CMYK representation nor special color. Examples thereof include RGB representation and representation in a device-independent color space (for example, various color spaces defined by CIE). Colors that are neither device CMYK nor special colors are not subject to color correction processing by the color correction unit 92. This is because these colors are converted into color values that reflect the characteristics of the printing apparatus 50 when the colors are converted into representations in the color space of the printing apparatus 50, as in the case of spot colors.

  Therefore, a color expression color other than such a special color in the PDL data and not a color correction target of the color correction unit 92 (referred to as “non-correction target color”. The non-correction target color does not include a special color). When the object is included, the color correction unit 92 may be controlled not to perform color correction on the non-correction target color portion of the drawing data in the buffer unit 80. For this purpose, for example, discrimination information indicating whether each area in the page is a non-correction target color (that is, device CMYK or spot color) may be used. In this example, for example, when the interpretation unit 34 generates intermediate data of an object, if the object is a non-correction target color, it is converted into a representation of the device CMYK, and the non-correction target color is added to the intermediate data. Set the flag to indicate. Then, when the non-correction target color flag is set in the received intermediate data, the drawing data generation unit 70 determines that the area of the drawing data generated from the intermediate data (the pixel group in which the drawing data exists) is not. The fact that it is the color to be corrected is written in the discrimination information. Then, when the color correction unit 92 performs color correction on the drawing data group in the buffer unit 80 in accordance with an instruction from the spot color determination unit 90, an area in the page indicating that the non-correction target color is indicated in the determination information. Does not perform color correction. In the above example, the interpretation unit 34 converts the non-correction target color into the device CMYK. Instead, for example, the drawing data generation unit 70 may perform this color space conversion when generating the drawing data. In this case, if the input intermediate data is the non-correction target color, the drawing data generation unit 70 may write in the determination information that the area of the drawing data generated from the intermediate data is the non-correction target color. As an example of such discrimination information, a tag plate (for example, similar to that described in Patent Document 4) having a bit indicating whether or not the pixel is a non-correction target color for each pixel of the page may be used. Good.

  10 terminal device, 20 print control system, 30 front end device, 32 print job receiving unit, 34 interpreting unit, 36 spot color smoothing unit, 38 spot color spool, 40 back end device, 42a first buffer, 42b second buffer, 43 Coupling unit, 44 drawing unit, 46 output buffer, 50 printing device, 60, 62, 64 communication means, 70 drawing data generation unit, 80 buffer unit, 82 buffer format determination unit, 84a bitmap format output unit, 84b run length format Output unit, 86 line buffer, 88 data format conversion unit, 90 spot color determination unit, 92 color correction unit, 94 data conversion unit.

Claims (6)

Means for dividing image element data in the intermediate data format in the output unit into spot color element data and non-spot color element data;
Drawing means for generating drawing data in the buffer by drawing the input non-spot color element data group and the spot color element data group in a buffer;
Color correction means for performing color correction on a portion to be corrected in the drawing data in the buffer;
After the drawing means finishes drawing for all the non-spot color element data in the output unit, and before starting drawing of the spot color element data in the output unit, the drawing data in the buffer at that time Control for causing the color correction unit to perform color correction, and after the color correction is completed, the drawing unit performs control to draw the spot color element data with respect to the color-corrected drawing data in the buffer Means,
An image processing apparatus.   The drawing means generates, in the buffer, drawing data having a data format in which a data amount of the region is smaller between a bitmap format and a compression format for each region in the output unit. Item 8. The image processing apparatus according to Item 1.   The image processing apparatus according to claim 2, wherein the compression format is a run-length type. The dividing means stores the non-spot color element data group derived from the image element data group in the output unit in a first buffer, and the spot color element data group derived from the image data element group in the output unit. In the second buffer,
The image processing apparatus further includes:
All the non-spot color element data groups in the output unit stored in the first buffer are supplied to the drawing means and then applied to the non-spot color element data groups stored in the second buffer. Supply means for supplying alignment information to the drawing means and then supplying the non-spot color element data group stored in the second buffer to the drawing means;
The control unit temporarily stops the operation of the drawing unit when the overlay information is supplied to the drawing unit, and causes the color correction unit to perform color correction on the drawing data in the buffer. 4. The spot color element data group supplied from the supply means is processed by resuming the operation of the drawing means after completion of the color correction. Image processing apparatus. Means for generating information indicating an area of non-spot color element data using a color expression other than device CMYK among the drawing data in the buffer;
The control means treats an area indicated as an area of non-spot color element data using a color expression other than the device CMYK in the information as not corresponding to the color correction target part. 5. The image processing apparatus according to any one of 4 above. Computer
Drawing that generates spot data in the buffer by inputting spot color element data and non-spot color element data in an intermediate data format within the output unit, and drawing the non-spot color element data group and the spot color element data group in the buffer Means,
Color correction means for performing color correction on a portion to be corrected in the drawing data in the buffer;
After the drawing means finishes drawing for all the non-spot color element data in the output unit, and before starting drawing of the spot color element data in the output unit, the drawing data in the buffer at that time Control for causing the color correction unit to perform color correction, and after the color correction is completed, the drawing unit performs control to draw the spot color element data with respect to the color-corrected drawing data in the buffer means,
Program to function as.