JP6794834B2 - Image processing equipment and programs - Google Patents

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 uses an intermediate data object input in the drawing order as a basic color object having the same shape as the object and having only basic color components, and individual spot colors having the same shape. It is decomposed into a spot color object for each spot color component that has only components, the basic color object is output, and the spot color object is stored in the spot color version spool. At this time, the shape of the existing spot color object in the spot color plate spool is changed to a shape excluding the portion hidden by the spot color object to be stored. Each time the object color separator finishes processing for all the objects for one page, the objects in each spot color spool are output while simulating the spot color components with the basic colors according to the stacking order of each spot color plate in printing. To do.

In the system disclosed in Patent Document 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 means. The spot color image data is extracted from this intermediate data by the spot color image data extraction unit, and the color information of the extracted spot color image data is converted into the color information expressed by the process color by the color information conversion unit. The transmittance information addition unit adds the transmittance information to the color information of the converted spot color image data. The drawing processing unit adds the colors of both image data based on the transparency information and color information of the special color image data determined by the overlap determination unit to have 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 Document 3 performs plate separation processing and RIP processing for each page to generate raster data of each color of CMYK and raster data corresponding to the spot color name, and then a CMYK value specified by the spot color name. Based on the above, the special color raster data is combined with the CMYK color raster data and output. As a result, the overprint of the spot-colored object is accurately reproduced in color.

In Patent Document 4, a flag value indicating whether or not each pixel is a spot color (that is, a process color) is recorded in plate data for control called a tag plate, and a tone adjustment or the like is performed for the color value of a non-spot color pixel. A control is disclosed in which color correction is performed and the color value of a spot color pixel is not subjected to the color correction.

JP-A-2015-188212 Japanese Unexamined Patent Publication No. 2015-026933 Japanese Unexamined Patent Publication No. 2004-148535 JP-A-2009-267927

In the method of creating control information indicating whether each pixel is a spot color or not and applying color correction only to pixels that are not spot colors by referring to this control information, color reproduction is performed for the part where the spot color is overprinted on the basic color of the background. Cannot be done correctly. This is because the pixels on which the spot color is overprinted are recorded as spot color pixels in the control information, so that color correction is not performed on the basic color of the base.

On the other hand, in the method of generating the raster data of each basic color plate and the special color plate respectively and synthesizing the raster data of the special color plate with the raster data of the basic color plate, after performing color correction on the raster data of the basic color plate, By synthesizing the raster data of the spot color version, it is possible to accurately reproduce the color of the spot color overprint. However, the computer that executes this method of processing needs a storage capacity for storing both the raster data of the basic color version and the raster data of the spot color version.

The present invention requires less memory than a method of generating raster data for each plate of basic colors and spot colors and synthesizing spot color raster data with color-corrected basic color raster data. The purpose is to reduce it.

The invention according to claim 1 is a means for dividing image element data in an intermediate data format in an output unit into spot color element data and non-special color element data, and the input non-special color element data group and the special 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 portion of the drawing data to be color-corrected in the drawing data, and the drawing means are described above. After finishing drawing of all the non-special color element data in the output unit and before starting drawing of the special color element data in the output unit, the color with respect to the drawing data in the buffer at that time. It has a control means for causing the correction means to perform color correction, and after the completion of the color correction, for controlling the drawing means to draw the special color element data on the color-corrected drawing data in the buffer. It is an image processing device.

According to the second aspect of the present invention, the drawing means generates drawing data in the buffer in the data format of the bitmap format or the compression format in which the amount of data in the region is smaller for each region in the output unit. The image processing apparatus according to claim 1, wherein the image processing apparatus is characterized in that.

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

In the invention according to claim 4, the dividing means stores the non-special 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 special color element data group derived from the above is stored in the second buffer, and the image processing apparatus further uses all the non-special color element data groups in the output unit stored in the first buffer as the drawing means. The overlay information to be supplied and then applied to the non-feature element data group stored in the second buffer is supplied to the drawing means, and then the non-feature element data stored in the second buffer is supplied. The control means has a supply means for supplying the group to the drawing means, and when the superposition information is supplied to the drawing means, the control means suspends the operation of the drawing means and draws the drawing in the buffer. The feature is that the color correction means performs color correction on the data, and after the color correction is completed, the operation of the drawing means is restarted to process the special color element data group supplied from the supply means. The image processing apparatus according to any one of claims 1 to 3.

The invention according to claim 5 further includes means for generating information indicating a region of non-spot color element data using a color representation other than device CMYK among the drawing data in the buffer, and the control means is said to be said. Any one of claims 1 to 4, wherein a region shown as a region of non-spot color element data using a color representation other than device CMYK for information is treated as not corresponding to the portion to be color-corrected. The image processing apparatus according to the above.

The invention according to claim 6 is to input the spot color element data and the non-feature element data in the intermediate data format in the output unit into the computer, and draw the non-feature element data group and the spot color element data group in a buffer. , A drawing means for generating drawing data in the buffer, a color correction means for performing color correction on a portion of the drawing data in the buffer to be color-corrected, and all the drawing means in the output unit. After the drawing of the non-special color element data is completed and before the drawing of the special color element data in the output unit is started, the color correction means performs color correction on the drawing data in the buffer at that time. This is a program for causing the drawing means to function as a control means for controlling the drawing data of the special color element to be drawn on the color-corrected drawing data in the buffer after the color correction is completed.

According to the invention of claim 1 or 6, as compared with a method of generating raster data for each plate of a basic color and a spot color and synthesizing the raster data of the spot color with the raster data of the basic color to which color correction has been performed. , The amount of memory required can be reduced.

According to the invention of claim 2, the amount of drawing data can be reduced as compared with the method in which the entire area is in either the bitmap format or the compressed format.

According to the invention of claim 3, the load of color correction of the color correction means can be reduced as compared with the case where the entire area is in the bitmap format, and the amount of drawing data is larger than that in the case where the entire area is in the run length format. Can be reduced.

According to the invention of claim 4, it is lower that the drawing of the last non-spot color element data in the output unit is completed than the method of examining the color information contained in each of the non-spot color element data and the spot color element data. It can be detected by the load.

According to the invention of claim 5, it is possible to accurately reproduce the color of non-spot color element data to which the color correction of the color correction means is not applied in addition to the spot color.

It is a block diagram which shows the example of the structure of an image processing system. It is a figure which shows the example of the functional configuration of the front-end apparatus and the back-end apparatus provided in the print control system. It is a figure which shows the specific example of the transition of the storage contents of a special color spool. It is a figure which shows an example of the processing procedure of the spot color smoothing part. It is a figure for demonstrating a specific example of processing of a spot color smoothing part. It is a figure which shows an example of the internal structure of a drawing part. It is a figure which shows an example of the processing procedure of a drawing part. It is a figure for demonstrating a specific example of processing of a drawing part. It is a figure which shows an example of the structure of the buffer part in a drawing part.

<System configuration of the embodiment>
FIG. 1 is a block diagram showing an example of the configuration of an image processing system. The example system of FIG. 1 includes a terminal device 10, a print control system 20, and a print device 50. The print control system 20 has 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 means 60, and sends a print job including a document print command to the front-end device 30 according to a user's instruction. The front-end device 30 is connected to the back-end device 40 via the communication means 62, and the back-end device 40 is connected to the printing device 50 via the communication means 64.

The communication means 60, 62, 64 may be, for example, a data communication network such as a LAN (Local Area Network). The communication means 60, 62, 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 between 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 of the above, 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 data of the processing result is passed to the back-end device 40, and printing is performed by the printing device 50 according to the image data generated by the back-end device 40. The image data in this embodiment refers to data in which an image to be printed is represented 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, for example, a general-purpose computer. 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 and from other devices via the communication interface. Further, an input device such as a keyboard or 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. Further, a secondary storage device such as an HDD (hard disk drive) or SSD (solid state drive) is connected to the bus via an I / O interface. Further, a disk drive for reading a portable non-volatile recording medium of various standards such as a DVD and a flash memory may be connected. Such a drive acts as an external storage device for memory. A program in which the processing contents of each embodiment described later are 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. When the program stored in the secondary storage device is read into the memory and executed by the CPU, the processing of the embodiment described later is realized.

In the example of each embodiment described later, a part of the functions of the back-end device 40 may be realized by hardware processing instead of software processing by executing a program. For hardware processing, for example, an integrated circuit such as an ASIC (Application Specific Integrated Circuit) is used. Further, for example, a processor called a dynamic reconfigurable processor (DRP), which can dynamically reconfigure a circuit in the middle of processing execution, may be used. For example, by preconfiguring hardware elements such as DRP and ASIC that execute a part of the functions of the back-end device 40 and connecting such hardware elements to the bus of a general-purpose computer, the back end device 40 can be backed up. The end device 40 may be realized.

As one specific example of the hardware that realizes 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 of which functions as a server, are mounted in one housing. A blade server is a server device in which a general-purpose computer equipped with a CPU and a memory is mounted on one 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 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 the 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 individual 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 processing each of these devices may be executed on the same computer).

The printing device 50 is a device that prints on a medium such as paper, and may be, for example, a continuous paper printer or a cut paper printer. The printing method of the printing apparatus 50 is not particularly limited. It may be an electrophotographic method or an inkjet method. Alternatively, other methods may be used.

FIG. 2 shows an example of the functional configuration 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 coupling 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 the present embodiment, the print job includes, for example, a command to print the document and data in which the document to be printed is described in the page description language. A page description language (abbreviated as PDL: PDL is an abbreviation for Page Description Language) is a computer programming language for causing an information processing device to execute display processing, printing processing, and the like. Examples of page description languages 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 characters, figures, images (bitmap images), and other objects that make up the document to be printed. In the following description, the data in which the document to be printed is described in the page description language is referred to as "PDL data". The print job receiving unit 32 passes the PDL data included in the received print job to the interpreting 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 an instruction indicating 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 paper with the printing device 50. The image data is data in which an image to be printed is expressed in a format that can be handled by the printing apparatus 50, and 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 subdivided into minute elements having a simpler shape. As the intermediate data format, various formats such as a display list format and a format shown in Patent Document 1 are known.

By interpreting the PDL data, the interpretation unit 34 decomposes each object represented by the PDL data into a unit shape (for example, a rectangular format, a run format, or a raster format) used in the intermediate data format, and decomposes each object into each unit shape. Generates data that represents its shape and color (which represents an object in an intermediate data format). The interpretation unit 34 decomposes the generated intermediate data format object into a basic color object consisting of only the basic color components and a spot color object consisting of only the spot color components. Here, the basic color is a primary color used for printing (for example, four colors of C, M, Y, and K), and is also called a process color. The basic color object and the spot color object obtained by decomposition differ only in the color data item indicating the color of the object, and the other data items inherit the data of the object before decomposition. The basic color object has only the values of each basic color component (for example, C, M, Y, K) as color data, and the spot color object is a set of, for example, the name of the spot color (spot 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 decomposing the objects to the first buffer 42a 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 that are sequentially output from the interpretation unit 34 in the intermediate data format. Further, a spot color simulation is performed in which the spot color of the smoothed spot color object is converted into the expression in the basic color of the printing apparatus 50. At the time of this smoothing, the spot color smoothing unit 36 makes the color of the portion where objects having the same spot color component overlap each other become the color of the spot color component itself (not the color in which the spot color components overlap). In addition, 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 the spot color objects in the 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 that order. Further, the second buffer 42b stores the spot color objects (however, converted to the basic color representation at this point) sequentially output from the spot color smoothing unit 36 in that order. The objects stored in the first buffer 42a and the second buffer 42b are in the intermediate data format. The coupling unit 43 combines the intermediate data stored in the first buffer 42a and the second buffer 42b and supplies the intermediate data to the drawing unit 44. That is, as a coupling process, the coupling unit 43 first supplies the intermediate data of the object group of the output unit accumulated in the first buffer 42a to the drawing unit 44 for each output unit, and then supplies the intermediate data of the object group in the second buffer 42b. The intermediate data of the object group of the output unit is supplied to the drawing unit 44. This order corresponds to the plate order in which the images of each plate of the basic colors are superimposed and the images of the spot color plates are superimposed in the traditional printing process. The output unit is a unit indicating the range of image data output to the printing device 50 by the back-end device 40 for each output process. Outputs pages, bands (one divided area when the page is divided into multiple parts in the sub-scanning direction), tiles (one divided area when the page is divided into multiple parts in both the main scanning direction and the sub-scanning direction), etc. This is an example of a unit. The drawing unit 44 generates drawing data for one output unit in the built-in buffer, converts the drawing data into image data, and outputs the drawing data to the printing device 50.

The drawing unit 44 draws the intermediate data of each object input in order from the connecting unit 43, finally generates the image data of the output unit, and writes the generated image data to 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. It may be converted to and output. The data format of the drawing data is closer to the image data than the intermediate data, but at least partially different from the image data. For example, this example corresponds to the case where the image data is in the raster format and the drawing data is in the run-length format.

In the drawing unit 44, the basic color object group in the output unit is first input in order from the connecting unit 43 for each output unit such as a page, and then the spot color object group is input. In this object input flow, the drawing unit 44, at that time, after the drawing of all the basic color objects in the output unit is completed and before starting the drawing of 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 device 50. As for the spot color object, when the spot color smoothing unit 36 converts the spot color into a basic color expression, the conversion that reflects the characteristics of the color space of the printing device 50 is performed, so that no color correction is required. Then, after the color correction is completed, the drawing unit 44 draws the spot color objects in the output unit in order on the color-corrected drawing data / image data, and synthesizes them.

The image data of each output unit generated by the drawing unit 44 is stored in the output buffer 46, and is sequentially read from the printing device 50. The printing device 50 prints the image data of each output unit read from the output buffer 46 on the paper.

Next, with reference to FIG. 3, the process performed by the spot color smoothing unit 36 will be described with reference to a specific example. 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) that are sequentially input from the interpretation unit 34 to the spot color smoothing unit 36 are displayed. It is shown together with numbers 1 to 3 indicating the order of production. The lower part of FIG. 3 shows the state of the object group in the special color spool 38 at the time when the upper special 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. From the knockout-designated object, such a special color object having a special color component value of 0 is generated. At this point, since there is no spot color object in the spot color spool 38 for the G version, the eclipse process is not performed. A spot color object having a spot color component value of "0" is for eclipsing an object of the spot color whose drawing order is earlier than that of the object to produce a knockout effect. Therefore, the spot color object having a value of "0" is used. It does not need to be drawn. Therefore, the first spot color object is not stored in the spot color spool 38. The second generated spot color object has color data of G = 0.01. Even at this point, 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 with the first spot color object (second in the input order) in the spot color spool 38. Therefore, the shape of the first spot color object in the spot color spool 38 is changed (eclipse) to the shape excluding the portion overlapping with the third spot color object in the input order. Further, the third spot color object is stored in the spot color spool 38 and becomes the second object in the spot color spool 38. If the third spot color object is the last object in the drawing order on the page 100, the object inside the spot color spool 38 when the above processing for the third spot color object is completed (this example). Then, two objects) will be output to the back-end device 40. For details of the eclipse processing, 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 then eclipses each object in the spot color spool 38 with the received spot color object (S32). When eclipse is completed for all the objects in the spot color spool 38, the received spot color objects are stored in the spot color spool 38 (S34). The above processing of S30 to S34 is 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), the spot color spool 38 at that time stores the spot color objects that do not overlap with each other. That is, the smoothing of the spot color objects in the output unit is completed. After that, the spot color smoothing unit 36 color-converts the color data of each spot color object in the spot color spool 38 from the spot color expression to the basic color expression (S38). Then, the spot color smoothing unit 36 outputs the instruction data to set the superposition 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 to reset the superposition information is output to the second buffer 42b (S44).

The superposition information is information that defines how to obtain the color value (pixel value) of the superposition result when the spot color plate is superposed on the background image (in this example, the image consisting of the basic color objects). is there. For example, the above-mentioned information such as the transmittance and the presence / absence of overprint designation is an example of the superimposed information. In addition, the overlay information is obtained when the result of adding 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). It may be information that defines how to determine (and how to adjust the values of other pixels accordingly). The overlay information, which is specified in the original PDL data in document units, page units, or object units, is inherited by the entire document, page, or object of the intermediate data (the object of the intermediate data is). , Generally, the PDL object is interpreted and further divided). The instruction data for setting the superposition information and the instruction data for resetting are stored in the second buffer 42b as one of the intermediate data in association with the output order in the same manner as the intermediate data of other feature 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 it (this application is performed by the drawing unit 44 of the back-end device 40). ..

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

It is assumed that the four objects 102A to D 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 designated as knockouts and the objects 102C and 102D are designated as overprints. Further, in this example, it is assumed that there is only one spot color (denoted as "Spot" in the figure).

In the example of FIG. 4, the colors (C, M, Y, K, Spot) of the object 102A are (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 overprint, if the density of a certain color component of an object is 0, the underlying color is transmitted as it is for that color component, so that color component is treated as "non-existent" (NA) in this object. Be told.

In this case, in the procedure of FIG. 4, 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. It is decomposed into objects. The basic color object is output to the first buffer 42a 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 with Spot = 0 is used for the eclipse processing of the object in the spot color spool 38, but since the value of the spot color component is "0" here, 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 object. Among them, the basic color object is output to the back-end device 40 (second in the "output intermediate data" column). A 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 of (C, M, Y, K) = (NA, NA, NA, NA) and a spot color object of Spot = 0.01. The object. Of these, the basic color object has all the basic color components of NA, so it is the same as if the object does not exist at all. Therefore, the basic color object is not sent to the first buffer 42a. On the other hand, the spot color object with Spot = 0.01 eclipses the spot color object in the spot color spool 38 and is 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 (Since the spot color object is not generated from the object 102C, it is omitted in FIG. 4).

When the above processing is completed, the spot color objects 102E and 102F are stored in the spot color spool 38. When the output of the basic color object for the fourth input object 102D and the processing related to the spot color spool 38 are completed, the spot color objects 102E and 102F in the spot color spool 38 are color-converted to 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 the accumulation of all the basic color objects and the spot color objects derived from one output unit in the first buffer 42a and the second buffer 42b is completed, the coupling unit 43 draws the intermediate data in the drawing unit 44. Output to. In this output, the coupling unit 43 first supplies the objects in the first buffer 42a to the drawing unit 44 in order, and after that, supplies the objects 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. Further, 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 representing the image to be printed. In this case, the drawing unit 44 does not have to 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 when both of them are in the same run-length format.

In another example, the drawing data may be in a data format closer to the image data than the intermediate data, but may be data in a data format that is at least partially different from the image data. For example, this example corresponds to the case where the image data format that can be handled by the printing apparatus 50 is the raster format, while the drawing data is the run-length format. In this case, the data conversion unit 94 performs a process of 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 in a hardware circuit. In addition, when the image data is in either raster format or run-length format, while the drawing data is data in which both raster format and run-length format are mixed (detailed examples will be described later), this example is also used. Applicable. The data conversion unit 94 converts the portion of this type of drawing data 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, the buffer unit 80 keeps the buffer unit 80 until the accumulation of drawing data generated from all the objects included in one output unit (which includes both the basic color object and the spot color object) is completed. The drawing data input from the drawing data generation unit 70 is accumulated in order. Then, when the accumulation 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 the intermediate data input in order from the coupling unit 43. When it is detected by this monitoring that the input of the spot color object is started, the spot color determination unit 90 suspends the generation of drawing data from the intermediate data (or the output of the generated drawing data) to the drawing data generation unit 70. In addition to instructing the color correction unit 92 to perform color correction. The spot color determination unit 90 may determine that the input of the spot color object has started when, for example, it detects the instruction data to set the superposition information from the intermediate data output in order from the coupling unit 43. .. However, this is just an example. Instead, the spot color determination unit 90 examines the color data of the intermediate data of each object output in order from the combination unit 43, and when the color data detects the first object showing the spot color, the input of the spot color object is input. It may be determined that it has started.

The drawing data generation unit 70, which has been instructed to pause by the spot color determination unit 90, pauses its operation before outputting the spot color object having the first output order in the output unit to the buffer unit 80. By the time this pause instruction arrives, the generation of drawing data for the basic object group of the output unit and the output to the buffer unit 80 have already been completed. Therefore, at this point in time, the buffer unit 80 is in a state in which drawing data groups generated from all the basic color object groups in the output unit are accumulated. At this time, the color correction unit 92 that receives the color correction instruction from the spot color determination unit 90 corrects the drawing data stored in the buffer unit 80. This color correction is a correction for reproducing the same color as the color in the color space of the PDL data in the color space of the printing apparatus 50. The color correction unit 92 writes back the color-corrected drawing data 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 the drawing data after color correction.

After the completion of this replacement, the color correction unit 92 instructs the drawing data generation unit 70 to restart the output of the drawing data. At the time of this instruction, drawing data generated from all the basic color objects in the output unit and having been color-corrected is stored in the buffer unit 80. When the drawing data generation unit 70 resumes the operation in response to the instruction, the intermediate data of the spot color object of 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 are written to the buffer unit 80 in this way, the buffer unit 80 finally outputs the drawing data held in the subsequent stage. When the drawing data has the same data format as the image data that can be handled by the printing device 50, there is no data conversion unit 94 after the buffer unit 80, and the drawing data in the buffer unit 80, that is, the image data is transmitted to the printing device 50. Be supplied. When the drawing data has a data format different from the image data that can be handled by the printing device 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. It is supplied to the printing device 50.

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

In this procedure, when the next intermediate data is input to the drawing unit 44 from the connecting unit 43 (S50), the data indicates the start of the spot color object (for example, the data indicating the set of the overlay information described above). ), The spot color determination unit 90 determines (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 to the buffer unit 80 (S54). Then, it is determined whether or not the object is the last object of the output unit (S56), and if the determination result is No, the process returns to S50 and the next intermediate data is input from the coupling unit 43.

When the determination result in S52 is Yes (that is, the input of the special color object group is started), the special 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. After that, the drawing data generation unit 70 does not output the drawing data of the object to the buffer unit 80 until there is a restart instruction. Therefore, at the time when this pause instruction 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 determination unit 90 instructs the color correction 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 executes color correction for matching the drawing data derived from the basic color object group in the buffer unit 80 to the color space of the printing device 50. The color-corrected drawing data is written back to the buffer unit 80.

When the color correction of the drawing data in the buffer unit 80 is completed (the determination result in S62 is Yes), the color correction unit 92 draws the drawing data generation unit 70 (or outputs the drawing data to the buffer unit 80). Is instructed to restart (S64). Upon receiving this instruction, the drawing data generation unit 70 restarts the drawing process (or output of the drawing data to the buffer unit 80). As a result, the drawing data generation unit 70 acquires from the coupling unit 43 in order from the head object of the spot color object group of the output unit (S50), generates drawing data of the spot color object, and buffers the generated drawing data. It is combined with the drawing data in 80 (S54). The processes of S50, S54, and S56 are repeated until the drawing process of the last feature color object of the output unit is completed. Then, when the drawing of the last special color object is completed, the drawing data generation unit 70 ends the drawing process. After that, 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 device 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 device 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 is an example in which the drawing data of the five objects 1 to 5 displayed at the right end of FIG. 5 are sequentially input to the drawing unit 44.

(1) When the drawing of the basic color objects 1 to 3 shown in FIG. 5 is completed, the drawing data 200 is stored in the buffer unit 80 (for the sake of clarity, the drawing data is schematically shown as an image in the figure). Is retained. In the drawing data 200, the basic color objects 2 and 3 are sequentially arranged on the area 202 in which the color corresponding to the basic color object 1 is (C, M, Y, K) = (1,0,1,0). It is an overlap. The color of the area 204 corresponding to the basic color objects 2 and 3 in the drawing data 200 is the same color as the basic color object 1 (C, M, Y, K) = (1,0,1,0).

(2) In the example of FIG. 5, since the basic color objects are 1 to 3, when these drawings are completed and the drawing data 200 is formed in the buffer unit 80, the drawing data generation unit 70 is temporarily stopped, and the drawing data generation unit 70 is paused. Color correction is performed by the color correction unit 92 for 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 colors of the rectangular (square) area 214 of the drawing data 210 of the composition result are the colors of the basic color objects 4 and 5 (0.9, 0.1, 0.9, 0) in the color correction result (0.9, 0.1, 0.9, 0) of the area 204. 0,0,0,0.01) is plate-synthesized (0.9,0.1,0.9,0.01). The color of the area 212 where the spot color objects do not overlap remains (0.9, 0.1, 0.9, 0), and the color of the area 216 of only the spot color objects is (0, 0, 0, 0.01). It becomes.

As described above, in the present embodiment, the front-end device 30 divides the intermediate data of the output unit into the basic color object and the spot color object and outputs them to separate buffers (first buffer 42a and second buffer 42b). Then, when the back-end device 40 first draws the intermediate data of all the basic color objects in the first buffer 42a into the buffer unit 80, the buffer before starting the drawing of the spot color objects 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 objects group can be correctly reproduced by the printing apparatus 50. Then, the drawing result of the spot color object group is combined with the drawing data that has undergone this 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.

Further, the system of the present embodiment holds the data of the basic color object and the special color object separately at the intermediate data stage, but at the drawing data stage, the basic color object group is drawn in the buffer unit 80 for color correction. After that, the special 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 (page buffer, etc.) for special colors in addition to the basic colors at the stage of drawing data in which the amount of data is much larger than that of the intermediate data. Therefore, the memory capacity requirement of the back-end device 40 is required. It will be relaxed.

Next, with reference to FIG. 9, 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.

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 a line buffer 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 the image to be printed, and hold the drawing data of the line. In this example, the image of one output unit is composed of (n + 1) lines from line 0 to line n. In the illustrated example, each line buffer 86-0 to 86-n (hereinafter collectively referred to as "line buffer 86" when it is not necessary to distinguish them) is in either a bitmap format or a run-length format, respectively. Stores the drawing data of.

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 dynamically executed each time the input object is drawn.

In the run length format, one run (a tuple of pixels having the same value) is represented by, for example, a set of coordinates of the start point and end point of the run and the pixel value (for example, density) of the run, so that the data of one run is a run. The data has a fixed length regardless of the number of pixels included in. Therefore, when the number of runs included in one line is small, the amount of drawing data for one line is smaller in the run-length format than in the bitmap format. However, when 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 the objects to be input in order after that, the number of runs in the line is monitored for each line, and the buffer format is changed to the bitmap format for the lines whose number of runs exceeds the threshold value. ..

The buffer format determination unit 82 holds the buffer format information of each line buffer 86. Then, when the drawing data of each line generated by the drawing data generation unit 70 is written to the corresponding line buffer 86, if the buffer format of the line is the 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 to the corresponding line buffer 86 in the bitmap format. Further, 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 run-length format and bitmap format can be realized by known digital circuits. For example, when the drawing data generation unit 70 generates run-length format drawing data, the bitmap format output unit 84a converts the drawing data into a bitmap format and writes it to the line buffer 86, and the run-length format output unit 84b writes the drawing data to the line buffer 86 in the run-length format.

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

As a result of writing the run-length format 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 when the number of runs in the line buffer 86 exceeds the threshold value. Instructs format conversion. Upon receiving the instruction, the data format conversion unit 88 reads the drawing data (run in this case) 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. Writes back the bitmap data of to the line buffer 86. As a result, the drawing data in the line buffer 86 is in a bitmap format. Then, the buffer format determination unit 82 stores that the data format of the line buffer 86 is a bitmap format, and subsequently passes the drawing data to be written to the line buffer 86 to the bitmap format output unit 84a.

Further, when a long single-color image is newly written to the line buffer 86 that holds the drawing data in the bitmap format 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 above threshold and below the second threshold). May become. In this case, the amount of drawing data is smaller when the drawing data in the line buffer 86 is returned to the run-length format. Therefore, in the buffer format determination unit 82, 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 the drawing data is written is represented in the run length format is calculated. When it is determined that the value is equal to or less than the second threshold value, the data format conversion unit 88 may be instructed to convert the drawing data of 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 value 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 may be converted by the data format conversion unit 88.

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 with respect to the drawing data held in each line buffer 86. To perform color correction. At this time, if the drawing data in the line buffer 86 is in the 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 that make up 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 run-length format line buffer 86 is much smaller than that of the bitmap format. There are few.

Then, after the color correction is completed, the drawing data generation unit 70 resumes the operation, and the drawing data of the spot color object is written to 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 format of drawing data in line units. Then, as the drawing data format of each line, a format in which the amount of drawing data of the line is small is selected from the bitmap format and the run-length format. In the present embodiment, the 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 conversion unit 94 and supplied to the printing apparatus 50. .. However, if the printing device 50 has a configuration capable of accepting and processing drawing data in which such data formats are mixed (for example, it has a built-in function of the data conversion unit 94), such a configuration can be performed from the back-end device 40. Drawing data in which data formats are mixed may be transmitted to the printing device 50 via the communication means 64. In this case, since the amount of data in the drawing data in which the data formats are mixed is smaller than that in the image data in a single format such as the bitmap format, the amount of communication in the communication means 64 can be reduced.

Further, 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 the 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 color-corrected is smaller than in the case where color correction is performed for each pixel. Therefore, the run-length format line requires less time for the correction processing of the color correction unit 92 than the bitmap format line. Therefore, the drawing data in which the data formats are mixed as illustrated above requires less time for color correction than the drawing data in the bitmap format as a whole. The drawing data in the run-length format as a whole may take less time for color correction than the drawing data in which the data formats are mixed as described above, but the amount of data may be larger than in the case where the data formats are mixed. high. As described above, in the evaluation of the drawing data in which the data formats are mixed by the method of the example of FIG. 9 in total, the large amount of data (the required memory capacity is small) and the processing load of the color correction are evaluated as the whole drawing data. Is better than unifying to bitmap format or run length format.

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

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

By the way, in the embodiment described above, the basic color to be color-corrected (that is, the basic color to be color-corrected by the color correction unit 92) is generally in the device CMYK color space. Since the device CMYK color space depends on individual devices (for example, printing devices), it is necessary to make corrections according to the characteristics of the printing device 50 used for output.

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

Therefore, the color of the color expression other than such a spot color in the PDL data and not the color correction target of the color correction unit 92 (referred to as "non-correction target color". The non-correction target color does not include the spot color). When the object of the above is included, the color correction unit 92 may control the drawing data in the buffer unit 80 so that the non-correction target color portion is not color-corrected. For this purpose, for example, discrimination information indicating whether or not each area in the page is a non-correction target color (that is, device CMYK or a spot color) may be used. In this example, for example, when the interpreting unit 34 generates the intermediate data of the object, if the object is the uncorrected target color, it is converted into the representation of the device CMYK and the uncorrected target color is added to the intermediate data. Set the indicated flag. Then, when the flag of the non-correction target color is set in the received intermediate data, the drawing data generation unit 70 does not have a drawing data area (pixel group in which the drawing data exists) generated from the intermediate data. Write in the discrimination information that it is the color to be corrected. Then, when the color correction unit 92 performs color correction on the drawing data group in the buffer unit 80 in response to the instruction of the spot color determination unit 90, the color correction unit 92 relates to a region of the page where the discrimination information indicates that the color is a non-correction target color. Does not perform color correction. In the above example, the interpretation unit 34 converts the non-correction target color into the device CMYK, but 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 discrimination 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 version (for example, one similar to that described in Patent Document 4) having a bit indicating whether or not the pixel is a non-correction target color may be used for each pixel of the page. Good.

10 terminal device, 20 print control system, 30 front-end device, 32 print job receiver, 34 interpreter, 36 spot smoothing section, 38 spot spool, 40 back-end device, 42a 1st buffer, 42b 2nd buffer, 43 Joining 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)

A means to divide the image element data in the intermediate data format in the output unit into spot color element data and non-spot color element data,
A drawing means for generating drawing data in the buffer by drawing the input non-special color element data group and the special color element data group in the buffer.
A color correction means for performing color correction on a portion of the drawing data in the buffer to be color-corrected,
After the drawing means has finished drawing all the non-special color element data in the output unit, and before starting drawing of the special color element data in the output unit, the drawing data in the buffer at that time. Control that causes the color correction means to perform color correction, and after the completion of the color correction, controls the drawing means to draw the special color element data on the color-corrected drawing data in the buffer. Means and
An image processing device having. The drawing means is characterized in that drawing data in a data format in which the amount of data in the region is smaller, whichever is smaller in the bitmap format or the compression format, is generated in the buffer for each region in the output unit. Item 1. 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-special color element data group derived from the image element data group in the output unit in the first buffer, and stores the non-special color element data group derived from the image data element group in the output unit. Is stored in the second buffer,
The image processing device further
All the non-feature element data groups in the output unit stored in the first buffer are supplied to the drawing means, and then applied to the non-feature element data group stored in the second buffer. It has a supply means for supplying the matching information to the drawing means and then supplying the non-feature element data group stored in the second buffer to the drawing means.
When the superimposition information is supplied to the drawing means, the control means suspends the operation of the drawing means and causes the color correction means to perform color correction on the drawing data in the buffer. The method according to any one of claims 1 to 3, wherein after the completion of the color correction, the operation of the drawing means is restarted to process the special color element data group supplied from the supply means. Image processing equipment. Further having a means for generating information indicating an area of non-spot color element data using a color representation other than the device CMYK among the drawing data in the buffer.
Claims 1 to 1, wherein the control means treats a region indicated as a region of non-spot color element data using a color representation other than the device CMYK in the information as not corresponding to the portion to be color-corrected. The image processing apparatus according to any one of 4. Computer,
A drawing in which the special color element data and the non-special color element data in the intermediate data format in the output unit are input, and the non-special color element data group and the special color element data group are drawn in the buffer to generate drawing data in the buffer. Means and
A color correction means for performing color correction on a portion of the drawing data in the buffer to be color-corrected.
After the drawing means has finished drawing all the non-special color element data in the output unit, and before starting drawing of the special color element data in the output unit, the drawing data in the buffer at that time. Control that causes the color correction means to perform color correction, and after the completion of the color correction, controls the drawing means to draw the special color element data on the color-corrected drawing data in the buffer. means,
A program to function as.