JP2017024321A - Image processor, image formation device, and image processing time prediction method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately predict a time required for block division rendering of PDL data.SOLUTION: An image processor for an image formation device having rendering means which generates bit map data which is divided into plural blocks by block division rendering for input PDL data comprises: prediction means which predicts a time required for generation of bit map data in the rendering means; and PDL data generation means for prediction which generates PDL data for prediction in which correction information for said prediction is added to the input PDL data. The prediction means executes said prediction on the basis of correction information included in intermediate data which is generated from the PDL data for prediction.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a technique for predicting the time required for image processing.

  Conventionally, an image forming apparatus having a function of notifying a user of a time required for print processing has been realized. For example, in Patent Document 1, a technique for receiving PDL (Page Description Language) data including a plurality of objects and predicting the time required for print processing from the number and size of drawing objects included in the PDL data (hereinafter referred to as required time prediction technique). ) Has been proposed.

  On the other hand, for example, block division rendering has been proposed as a technique for reducing the memory capacity required for rendering processing (Patent Document 2). This is a process of rendering the intermediate data generated from the PDL data, and generates bitmap data by dividing the vector data included in the intermediate data into a plurality of blocks (small areas), and compresses the image for each block. To do. As a result, the memory capacity used in the rendering process can be reduced.

JP 2003-216359 A JP 2012-254583 A

  In the block division rendering method disclosed in Patent Document 2, division processing is performed during rendering processing based on intermediate data generated from PDL data. When the required time prediction technique disclosed in Patent Document 1 is applied to such block division rendering, since the PDL data before division is used for prediction, it is difficult to accurately predict the time required for rendering processing. This is because, in the case of an object that spans multiple blocks, bitmap data corresponding to only a part of the object is generated in each block, but such processing time in units of blocks is not considered. It is.

  An image processing apparatus according to the present invention is an image processing apparatus for an image forming apparatus having a rendering unit that generates bitmap data divided into a plurality of blocks by block division rendering with respect to input PDL data. Prediction means for predicting the time required to generate bitmap data; and prediction PDL data generation means for generating prediction PDL data in which correction information for prediction is added to the input PDL data. The means is characterized in that the prediction is performed based on correction information included in the intermediate data generated from the prediction PDL data.

  According to the present invention, it is possible to accurately predict the time required for block division rendering of PDL data.

It is a block diagram which shows the structural example of an image processing system. FIG. 3 is a block diagram illustrating an internal configuration of a printer control unit. 10 is a flowchart illustrating a processing flow when outputting an arbitrary print job designated by a user among the retained print jobs. It is a figure which shows an example of the list display screen of a deferred job. It is a figure which shows an example of PDL data. It is a figure which shows an example of a display list. It is a flowchart which shows the flow of a block division | segmentation rendering process. It is a figure which shows the result of having performed the sort process with respect to the edge data extracted from the scan line. It is a figure explaining span information. It is a figure explaining the production | generation process of level information. It is a figure which shows an example of the result of block division. It is a figure which shows an example of a clip command. It is a flowchart which shows the flow of a printing required time calculation process. It is a figure which shows an example of PDL data for prediction. It is a figure which shows the display list produced | generated based on the PDL data for prediction. It is a flowchart which shows the detail of the PDL data for prediction generation processing.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

[Example 1]
FIG. 1 is a block diagram illustrating a configuration example of an image processing system according to the present embodiment. The image processing system 100 includes a host computer 110 as an information processing apparatus that generates print data (PDL data) and a printer 120 as an image forming apparatus that performs image processing on input PDL data and prints it out. Connected through. The printer 120 may be an MFP (Multi Function Peripheral) having a plurality of functions such as copying and FAX, or may be an SFP (Single Function Printer) having only a printing function. Further, as a method used for image formation, for example, an electrophotographic method or an ink jet method can be considered, but the method is not limited thereto. Furthermore, the host computer (hereinafter referred to as host PC) 110 and the printer 120 are connected via the LAN 130, but the connection method is not limited to this. For example, an arbitrary network such as a WAN represented by a public line, a serial transmission method such as USB, and a parallel transmission method such as Centronics and SCSI can be applied.

  The host PC 110 can send and receive files and send and receive emails using a protocol such as FTP and SMB via the LAN 130. Further, the host PC 110 stores an application program for creating a document to be printed and a printer driver for creating a print job in a storage unit (not shown) such as an HDD. Note that the print job created by the printer driver includes print settings and print data (PDL data) created by the user. The print settings include information such as a user ID, paper size, color / monochrome printing, duplex printing, and the number of output copies.

  The printer 120 includes a control unit 121, an operation unit 122, and a printing unit 123. The control unit 121 is connected to the operation unit 122 and the printing unit 123, and controls operation of the entire printer 120 by controlling operations of these units. The control unit 121 transmits and receives image data and the like to and from an external device including the host PC 110 via the LAN 130. The operation unit 122 includes an input button and a touch panel / display, and receives an input operation such as a change to the print setting when outputting a retained print job, for example, from the user. The operation unit 122 also displays an image on the display based on an instruction from the control unit 121. Information related to the user's input operation is sent to the control unit 121. The printing unit 123 receives the image data (bitmap data) processed by the control unit 121 and executes a printing process based on the image data.

  FIG. 2 is a block diagram illustrating an internal configuration of the control unit 121 of the printer 120. A CPU 201 is a central processing unit for controlling the entire printer 120. Note that the CPU 201 may be composed of a plurality of CPUs. A RAM 202 is a work memory for the CPU 201 to operate, and is also an image memory for temporarily storing input image data. The RAM 202 is also called main memory. A ROM 203 is a boot ROM, and stores a system boot program. The HDD 204 stores system software programs for various processes, input image data, and the like.

  The operation unit I / F 205 is an interface for connecting the operation unit 122 and the control unit 121, and outputs image data for displaying various input operation UI screens on the operation unit 122. The operation unit I / F 205 plays a role of transmitting various information input by the user to the CPU 201 via the UI screen displayed on the operation unit 122.

  A network I / F 206 is realized by a LAN card or the like, and is connected to the LAN 130 to input / output information to / from an external device.

  An image bus I / F 207 is an interface for connecting the system bus 208 and an image bus 209 that transfers image data at high speed, and is a bus bridge that converts a data structure. On the image bus 209, a raster image processor (RIP) 210, a device I / F 211, a print image processing unit 212, an image editing image processing unit 213, and a color management module (CMM) 214 are connected. The RIP 210 expands page description language code (PDL data) and vector data described later into bitmap data. The device I / F 211 is an interface between the printing unit 123 and the control unit 121, and performs synchronous / asynchronous conversion of image data.

  The print image processing unit 212 performs image processing such as density correction and resolution conversion according to the printer engine of the printing unit 123 on the image data printed by the printing unit 123. The editing image processing unit 213 performs various types of image processing such as rotation and compression / decompression on the image data. The CMM 214 is a dedicated hardware module that performs color conversion processing (also referred to as color space conversion processing) on image data based on a color profile and calibration data. The color profile is information such as a function for converting color image data expressed in a device-dependent color space into a device-independent color space (for example, Lab). The calibration data is data for correcting the color reproduction characteristics of the printing unit 123.

<Definition of terms>
Here, definitions of terms in the present specification will be described.
An edge is an outline of an object, and refers to an object to be drawn in a page or a boundary between an object and a background.

  A scan line is a line in the main scanning direction in which image data is continuously subjected to memory scanning in the image forming process, and the height of the scan line is 1 pixel. A bundle of a plurality of scan lines is called a band.

  A span refers to a closed region enclosed between edges in a single scan line. That is, it means a closed region in a line having an edge as an end point when one scan line is divided by the edge of the object.

  The level indicates the vertical relationship between objects drawn on the page, and each object is always assigned a different level number.

  Fill refers to paint information for a span. There are fills having different color values for each pixel such as bitmap data and shading, and fills in which color values do not change in the span, such as solid coating.

<Print processing flow>
Next, the printing process in the printer 120 will be described. In this embodiment, a series of processes from temporarily holding a print job received from the host PC 110 to receiving an output instruction for the held print job from the user and printing will be described. FIG. 3 is a flowchart showing a processing flow when outputting an arbitrary print job designated by the user among the reserved print jobs. This series of processing is realized by developing a program stored in the ROM 203 or the HDD 204 in the RAM 202 and executing it by the CPU 201.

  In step 301, the CPU 201 detects a user login notified from the operation unit 122.

  In step 302, the CPU 201 searches for all print jobs that have been reserved by the logged-in user from all the reserved print jobs (reservation jobs), and displays a list on the display of the operation unit 122. FIG. 4 is a diagram illustrating an example of a list display screen of reserved jobs related to the login user. The list display screen 400 includes a display field 401 indicating the user ID of the login user, and a display field 402 indicating the contents of the log-in user's reservation job and the time required to output each print job (required printing time). The time required for printing displayed in the display column 402 is a time obtained by adding the time required for the block division rendering process to the time expected to be required from paper feeding to paper discharge. It should be noted that the time required for predetermined image processing in step 307, which will be described later, is included in the time required from paper feeding to paper discharge. In this embodiment, the required print time displayed in the display field 402 is a highly accurate predicted time considering block division rendering. Then, the user checks and selects a check box 403 of a print job desired to be printed, and presses a print start button 404 to start print processing of the selected print job.

  In step 303, the CPU 201 determines whether or not pressing of the print start button 404 is detected. If an arbitrary print job is selected from the list and printing start is instructed, the process proceeds to step 304. At this time, the CPU 201 loads the PDL data included in the selected print job from the HDD 204 to the RAM 202. On the other hand, if pressing of the print start button 404 cannot be detected, monitoring is continued.

  In step 304, the CPU 201 interprets the type of PDL, the data resolution for rendering, and the drawing command for the loaded PDL data. FIG. 5 is a diagram illustrating an example of PDL data, which includes a page start (layout) command 501 and two types of square drawing commands 502 and 503. FIG. 5A shows an image to be printed and having a resolution of 600 dpi. The paper size (Media) is A4 (210mm x 297mm) and the page orientation (Orientation) is specified as Portrait with the long side vertical. In this case, the width and height of the bitmap data to be generated (Area Size) ) Is “4960pixel × 7040pixel”.

  In step 305, the CPU 201 generates a display list (DL) that is intermediate data for rendering based on the result interpreted in step 304. FIG. 6 shows a display list corresponding to the PDL data of FIG. As shown in FIG. 6, the display list includes start coordinates and end coordinates of line segments that are derived from information on the path point sequence (vertex of the figure) of the object for each of the three types of objects. , Inclination information is stored as edge data. The generated display list is stored in the RAM 202. That is, since three edges are generated from each of the rectangular objects 1, 2, and 3 as shown in FIG. 6, the display list stored in the RAM 202 includes 9 (3 × 3). Edges will be included.

  In step 306, the CPU 201 requests the RIP 210 to render the generated display list. In response to this request, the RIP 210 executes a rendering process and generates bitmap data. As described above, in this embodiment, rendering processing by block division is executed. Details of the block division rendering will be described later.

  In step 307, the CPU 201 requests the print image processing unit 212, the editing image processing unit 213, and the CMM 214 to perform predetermined image processing on the bitmap data that is the rendering result. In response to this request, the print image processing unit 212, the editing image processing unit 213, and the CMM 214 perform rotation, color conversion processing, density correction processing, and the like in accordance with the paper transport direction on the bitmap data. .

  In step 308, the CPU 201 requests the printing unit 123 to print bitmap data that has undergone image processing. Upon receiving the request, the printing unit 123 executes printing processing and outputs the printed paper.

  The contents of the reservation printing process in the printer 120 have been described above.

  Next, the block division rendering process in step 306 described above will be described. This block division rendering process is a process of reading information for sequentially rendering each scan line to be processed from a display list and outputting it to image data in block units having a size of, for example, 1240 pixels × 1240 pixels. Block division rendering by the RIP 210 is realized by the CPU 201 developing a predetermined program stored in the ROM 203 or the HDD 204 in the RAM 202 and executing it. In the following, description will be given according to the flowchart showing the flow of the block division rendering process shown in FIG.

  In step 701, the RIP 210 receives a display list. Specifically, the display list to be subjected to block division rendering is expanded on the RAM 202 by the CPU 201.

  In step 702, the RIP 210 analyzes the display list for each scan line, and extracts edge data for sequential rendering. For example, when analyzing the 1000th scan line in the display list shown in FIG. 6, the intersection of the straight line and the scan line is calculated for each object based on the straight line information constituting the object.

  In step 703, the RIP 210 performs sort processing on the edge data extracted from the target scan line. FIG. 8 is a diagram showing a result of performing the sort process on the edge data extracted from the 1000th scan line. The sort process results for the edge data in the three types of objects 1 to 3 in FIG. It is shown. By sequentially loading the edge data of the objects 1 to 3, and determining the insertion position based on the X coordinate of the edge and sorting, the sorted edge data in a list format as shown in FIG. 8 is obtained.

  In step 704, the RIP 210 generates span information in the scan line of interest from the sorted edge data, sorts objects existing in the span in order of level, and generates level information of objects necessary for drawing. FIG. 9 is a diagram illustrating span information obtained for the band 901 in the page 900 corresponding to the PDL data in FIG. As shown in FIG. 9A, a band 901 having a predetermined band height is divided into three regions in the vertical direction (sub-scanning direction) according to the position of the object, and then spans 1 to 7 are spanned. Divided into 7 spans. More specifically, the region 1 includes spans 1 corresponding to the number of lines corresponding to the height of the region 1. The area 2 includes spans 2 and 3 corresponding to the number of lines corresponding to the height of the area 2. The area 3 is composed of the span 4, the span 5, the span 6 and the span 7 corresponding to the number of lines corresponding to the height of the area 3. FIG. 9B shows span information that defines what and how to draw in each of the spans 1 to 7. Here, “ROP2” in the span information of the span 5 means a binary raster operation. The fill information files 1 to 3 having different contents are associated with the level numbers 1 to 3, respectively. In this case, four pieces of span information of spans 4 to 7 are generated for the 1000th line belonging to the region 3.

  Then, based on such span information, object level information necessary for drawing is also generated. FIG. 10 is a diagram illustrating a generation process of level information generated for the span 5 among the four spans included in the 1000th line. FIG. 10 shows the result of sorting the three types of objects 1 to 3 existing in the span 5 in order of level. That is, the sort processing result when loading in the order of “level number 3 / fill 3 object 3”, “level number 1 / fill 1 object 1”, “level number 2 / fill 2 object 2” is shown. Yes. As shown in FIG. 10, when each object is loaded, the objects are sorted so as to be arranged in the order of levels in the linked list according to the level number. When all the objects existing in the span are loaded, the level information of the actually drawn object is selected and output. For example, in the case of span 5 shown in FIG. 10, it is necessary to erase the hidden surface except for the object positioned at the foreground unless the object to be loaded is designated for the synthesis process or the transparent process. Therefore, in the example of FIG. 10, only the level information of the object 3 with the level number 3 that is finally drawn is output. In this way, span information about the target scan line and level information corresponding to the span information are output.

  In step 705, the RIP 210 stores the span information and level information for the target scan line generated in step 704 in the work buffer.

  In step 706, the RIP 210 determines whether the span information and level information for each scan line stored in the work buffer is stored for a scan line of a predetermined block height. If the span information and the level information of the scan line for a predetermined block height (for example, 1240 pixels) have not been stored yet, the process returns to step 702 and the process continues with the next scan line as the target scan line. On the other hand, if the scan line span information and level information for a predetermined block height are stored, the process proceeds to step 707.

  In step 707, the RIP 210 divides spans spanning predetermined coordinates based on span information and level information for a predetermined block height stored in the work buffer, and all spans fit within the predetermined block. (Block division). FIG. 11 is a diagram illustrating a result of block division of seven spans (spans 1 to 7) included in regions 1 to 3 in the band 901 in FIG. 9A. As shown in FIG. 11A, spans 1 to 7 in a total of three regions 1 to 3 in a band 901 in FIG. 9A are divided by a predetermined block width, resulting in a total of 12 regions 4. In -15, it is subdivided into 14 spans 1-14. Specifically, the block 1 is composed of a span 1 corresponding to the number of lines of the height of the region 4, a span 5 corresponding to the number of lines corresponding to the height of the region 5, and spans 9 and 10 corresponding to the number of lines corresponding to the height of the region 6. Is done. The block 2 includes a span 2 corresponding to the number of lines corresponding to the height of the region 7, a span 6 corresponding to the number of lines corresponding to the height of the region 8, and a span 11 corresponding to the number of lines corresponding to the height of the region 9. The block 3 includes a span 3 corresponding to the number of lines corresponding to the height of the region 10, a span 4 corresponding to the number of lines corresponding to the height of the region 11, and spans 12 and 13 corresponding to the number of lines corresponding to the height of the region 12. The block 4 includes a span 4 corresponding to the number of lines corresponding to the height of the region 13, a span 8 corresponding to the number of lines corresponding to the height of the region 14, and a span 14 corresponding to the number of lines corresponding to the height of the region 15. Thus, the number of spans changes (increases) before and after block division.

  In step 708, the RIP 210 performs fill processing and composite processing on the span of interest in the block of interest among the divided blocks. For example, when span information and level information for a scan line corresponding to the block height corresponding to the band 901 in FIG. 11A are stored in the work buffer, block 1 is first determined as the target block, and the span is Fill processing and composite processing are performed based on the span information and level information with 1 as the target span.

  In step 709, the RIP 210 determines whether fill processing and composite processing have been completed for all spans in the block of interest. As a result of the determination, if there is an unprocessed span in the block of interest, the process returns to step 708. For example, if the process for span 1 is completed, the next span 5 becomes the target span and the process is continued. On the other hand, if there is no unprocessed span in the block of interest, the process proceeds to step 710.

  In step 710, the RIP 210 determines whether fill processing and composite processing have been completed for all scan line spans (all spans after block division) stored in the work buffer. If there is an unprocessed span (that is, there is an unprocessed block), the process returns to step 708 to determine the next block as the target block, and the processing is continued. For example, if the process for block 1 is completed, the next block 2 becomes the target block, the process is continued, and the process is repeated until the process for block 4 is completed.

  In step 711, the RIP 210 determines whether the rendering process has been completed for all the scan lines for the received display list. If there is an unprocessed scan line, the process returns to step 702 to determine the next target scan line and continue the process. On the other hand, if the rendering process has been completed for all the scan lines, this process ends.

  The above is the content of the block division rendering process by the RIP 210. As described above, the number of spans increases due to the block division, and therefore, fill / composite processing for the increased number of spans newly occurs. However, the PDL data sent from the host computer 110 is not configured in consideration of block division rendering executed by the RIP 210. If information indicating the occurrence and position of block division processing can be included in the PDL data, the time required for block division rendering can be accurately predicted.

  In this embodiment, PDL data in which a clip command as correction information is added at a position where block division processing occurs is generated, and an accurate processing time is predicted using this. Here, the clip command is a drawing command for instructing to cut out a drawing object existing at a position specified by the command into a shape (for example, a rectangle) specified by the clip command. FIG. 12 is a diagram illustrating an example of a clip command. In FIG. 12, an image 1202 is formed as a result of the drawing object 1200 being cut out in the shape specified by the clip command 1201.

  When such clip processing is executed by the RIP 210, span information is divided by position coordinates (edges) designated by the clip command, and span information existing outside the closed region indicated by the position coordinates after division is deleted. This cuts out the shape specified by the clip command. Therefore, processing equivalent to block division actually executed by the RIP 210 can be reproduced by clip processing based on the clip command.

  Next, the process for calculating the required printing time with high accuracy, which is a feature of this embodiment, will be described. FIG. 13 is a flowchart showing the flow of the required print time calculation process. This series of processing is also realized by developing a program stored in the ROM 203 or the HDD 204 in the RAM 202 and executing it by the CPU 201.

  When a print job to be reserved for printing is received from the PC 110, in step 1301, the CPU 201 extracts one page of PDL data from the PDL data in the received print job.

  In step 1302, the CPU 201 generates PDL data (hereinafter referred to as prediction PDL data) for predicting the time required for rendering processing for the page from the extracted PDL data for one page. This prediction PDL data is PDL data to which a clip command corresponding to each block at the time of block division is added. The process for generating the prediction PDL data will be described later with reference to FIG.

  In step 1303, the CPU 201 generates a display list from the generated prediction PDL data, and predicts a time expected to be required for the rendering process based on the display list. Specifically, based on the number of edges included in the generated display list, the edge height obtained by adding all the edges, the number of spans, and the processing time required for generating one pixel data for the RIP 210, the predicted time of block division rendering processing ( Hereinafter, a rendering rendering time) is calculated. When the rendering prediction time is calculated, the generated display list is discarded without being stored in the RAM 202 or the HDD 204.

  FIG. 15 shows a display list generated based on the prediction PDL data of FIG. In addition to the three types of objects shown in FIG. 6, information on the start coordinates, end coordinates, and inclinations of straight lines constituting the rectangular object corresponding to the inserted 24 clip commands is stored as edge data. Thus, the display list generated based on the prediction PDL data shown in FIG. 14 has 27 drawing commands, whereas the original display list (see FIG. 6) has 3 drawing commands. It will have a drawing command. Then, the total number of edges, which was 9 (3 × 3 per object) in the original display list, is increased to 81 (3 × 27) in the display list of FIG. As a result, the total edge height obtained by adding the heights of all the edges becomes 56320 (1240 * 2 * 20 + 840) for the rectangular object from 20680 (7040 * 2 + 1000 * 2 + 2300 * 2) in the original display list. * 2 * 4) will increase to 77,000. Although not shown in the figure, the total number of spans in the page is increased from 11 to 48 by block division. For example, for the four blocks in the first row in FIG. 15, after the block division, the number of spans is 14 as shown in FIGS. 11 (a) and 11 (b). Is recorded as 7. Since the fill (painting information) in the span does not change, the number of pixel data generated by the RIP 210 (for example, in the case of CMYK, one pixel data is 32 bits) can be calculated from the edge height obtained by adding all the edges and the number of spans. Then, the rendering prediction time can be calculated by multiplying the calculated number of pixel data by the processing time required for the RIP 210 to generate one pixel data.

  In step 1304, the CPU 201 determines whether or not the calculation of the rendering prediction time has been completed for the PDL data for all pages included in the received print job. If there is a page whose rendering prediction time has not yet been calculated, the process returns to step 1301 to continue the process for the next page. On the other hand, if the calculation of the rendering prediction time has been completed for the PDL data for all pages included in the received print job, the process proceeds to step 1305.

  In step 1305, the CPU 201 associates a value obtained by adding the time from paper feeding to paper discharge with the estimated rendering time calculated for the PDL data for all pages with the print job reserved as the required printing time. And stored in the RAM 202 or the HDD 204.

  In this way, each time a print job is received from the PC 110, the printer 120 calculates the required print time for the received print job and holds the print job in the apparatus. When a print instruction is received from the user for the retained print job, the value stored in association with the print job is displayed as the required time required to output the print job together with the print setting information (FIG. 4 described above). See).

  Next, the prediction PDL data generation process according to step 1302 described above will be described in detail. FIG. 16 is a flowchart showing details of the PDL data generation process for prediction.

  In step 1601, the CPU 201 acquires block size (height and width) information used in the block division rendering process. This block size information is stored in advance in the ROM 203 or HDD 204. When the blocks are divided as shown in FIG. 14 described above, 1240 pixels are acquired as the block size information in both width and height. Note that the size of the block located at the end of the page may be different from other blocks so as not to exceed the page size. For example, in the example of FIG. 14, the height of the block located at the end of the page in the y-axis direction is 840 pixcel.

  In step 1602, the CPU 201 acquires data resolution, paper size, and page direction information for the PDL data of the processing target page. In the case of the PDL data shown in FIG. 5, “resolution: 600 dpi”, “paper size: A4”, and “page direction: Portrait” are acquired. If the PDL data does not include resolution and paper size information, preset default values may be acquired.

  In step 1603, the CPU 201 determines the width and height of the bitmap data to be generated from the data resolution, paper size, and page direction information acquired in step 602. As described above, since the paper size (Media) is A4 and the page direction (Orientation) is Portrait, the width and height (Area Size) of the generated bitmap data is 4960 pixels × 7040 pixels. At this time, a value indicating the height of the bitmap data is a Y coordinate that specifies the end position in the page height direction (hereinafter, page end Y coordinate), and a value indicating the width specifies the end position in the page width direction. This is obtained as coordinates (hereinafter, page end X coordinate).

  In step 1604, the CPU 201 determines, based on the block size acquired in step 1601, position coordinates (hereinafter, referred to as “start position” and “end position”) in the height direction of the target block to be processed in the PDL data of the processing target page. Derived as “start Y coordinate” and “end Y coordinate”, respectively). For example, in the case of the block in the first row shown in FIG. 14, the start Y coordinate is 1 pixel and the end Y coordinate is 1240 pixels. Further, the start Y coordinate and the end Y coordinate for the blocks in the second and subsequent lines are obtained by adding the block height to each of the current start Y coordinate and end Y coordinate. For example, in the block in the second row shown in FIG. 14, the start Y coordinate is 1241 pixels and the end Y coordinate is 2480 pixels.

  In step 1605, the CPU 201 determines whether the start Y coordinate obtained in step 1604 exceeds the page end Y coordinate obtained in step 1603. If the start Y coordinate of the block of interest exceeds the page end Y coordinate, the process proceeds to step 1609. On the other hand, if the start Y coordinate of the block of interest does not exceed the page end Y coordinate, the process proceeds to step 1606.

  In step 1606, the CPU 201 determines, based on the block size acquired in step 1601, the position coordinates that specify the start position and end position in the width direction of the target block for the PDL data of the processing target page (hereinafter referred to as “start X coordinate”, respectively) And “end X-coordinate”). For example, in the block in the first column shown in FIG. 14, the start X coordinate is 1 pixel and the end X coordinate is 1240 pixels. Further, the start X coordinate and the end X coordinate for the blocks in the second column and thereafter are obtained by adding the block width to each of the current start X coordinate and end X coordinate. For example, in the block in the second column shown in FIG. 14, the start X coordinate is 1241 pixels and the end X coordinate is 2480 pixels.

  In step 1607, the CPU 201 determines whether the start X coordinate obtained in step 1606 exceeds the page end X coordinate obtained in step 1604. If the start-X coordinate of the block of interest exceeds the page end X-coordinate, the process returns to step 1604 to determine the start Y coordinate and end Y coordinate of the next block of interest and continue the processing. On the other hand, if the start X coordinate of the block of interest does not exceed the page end X coordinate, the process proceeds to step 1608.

  In step 1608, the CPU 201 generates a clip command for a rectangular object that is inscribed from the start coordinate to the end coordinate of the target block obtained in step 1604. This rectangular object clip command is a command for extracting (extracting) a portion of one or more objects included in the block of interest within the block of interest. Then, the CPU 201 expands the generated rectangular object clip command in the RAM 202. Then, the process returns to step 1606, and the CPU 201 determines the next block of interest (the block on the right) on the same Y coordinate and continues the process. This process of developing the clip command in the RAM 202 is a process in the process of generating PDL data including correction information, and the final command group on the RAM 202 obtained through the process of step 1609 described below is used for prediction. PDL data.

  In step 1609, the CPU 201 expands the drawing command for the object (initial object) included in the PDL data of the processing target page in the RAM 202 so as to follow the above-described rectangular object clip command. That is, the CPU 201 copies each command in the PDL data of the processing target page after the clip command obtained in step S1608 described above. The reason why the rectangular object clip command is expanded first is that if it is after the initial object, the original object drawn in the block cannot be clipped. By completing step 1609 as described above, prediction PDL data in which a clip command as correction information is added to the PDL data (input PDL data) of the input processing target page is generated on the RAM 202.

  FIG. 14 is a diagram showing an example of the prediction PDL data generated in this way, and a total of 24 clip commands are added to the PDL data of the original processing target page (PDL data in FIG. 5). Prediction PDL data. The breakdown of the 24 clip commands includes 20 clip commands 1401 for clipping with a rectangular object of 1240 pixels × 1240 pixels and four clip commands 1402 for clipping with a rectangular object of 1240 pixels × 840 pixels.

  In this embodiment, the coordinates of the rectangular object to be inserted at the time of generating the prediction PDL data are derived. However, the clip command of the rectangular object to be inserted corresponding to the combination of the paper size, resolution, and page direction is obtained in advance. You may ask for it. The information may be stored in the HDD 204 and acquired.

  In this embodiment, the PDL data for prediction is generated by adding a clip command of a rectangular object corresponding to a block at the time of block division rendering. However, the present invention is not limited to this. Any PDL data to which correction information capable of specifying a corresponding portion of an object to be rendered in each block at the time of division may be added, and the addition of a clip command is not essential.

  Finally, the accuracy of the prediction time using the prediction PDL data of this embodiment will be described.

  For example, the region 1 in FIG. 9A is divided into a region 4, a region 7, a region 10, and a region 13 in FIG. Since the fill (painting information) in the span does not change, the pixel data generated in the region 1 in FIG. 9A is run-length encoded data of the same color for 4960 pixcels. On the other hand, in the case of FIG. 11A, the run-length encoded data is 1240 pixcel. If 64 bits (8 bytes) are required for run-length encoded data (repetition information) for one color, the run-length encoded data generated by the presence or absence of block division increases from 88 bytes to 384 bytes in the example of FIG. 9A. . If the transfer speed of the image bus 209 is 250 Byte / μsec, the data that required 0.352 μsec to output the pixel data will need 1.536 μsec.

  By applying this embodiment and inserting a clip command into the prediction PDL data, it becomes possible to know the span information to be divided, and the difference (1.536 μsec−0.352 μsec) generated during the conventional prediction processing is 1.184 μsec difference Can be eliminated.

  As described above, according to the present embodiment, prediction PDL data that takes into account the processing load of block division rendering is generated. Since the prediction PDL data generated at this time does not divide the drawing command, the prediction PDL data can be generated regardless of the tendency of the drawing object included in the input PDL data.

  Accordingly, it is possible to calculate the rendering prediction time that takes into account the block division processing while suppressing an increase in memory usage when predicting the time required for the block division rendering processing.

(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

Claims (10)

An image processing apparatus for an image forming apparatus having rendering means for generating bitmap data divided into a plurality of blocks by block division rendering for input PDL data,
Prediction means for predicting the time required to generate bitmap data in the rendering means;
Prediction PDL data generation means for generating prediction PDL data in which correction information for prediction is added to the input PDL data;
With
The image processing apparatus, wherein the prediction means performs the prediction based on correction information included in intermediate data generated from the prediction PDL data.   The image according to claim 1, wherein the prediction PDL data generation unit generates the prediction PDL data by adding a drawing command corresponding to each block to the input PDL data as the correction information. Processing equipment.   The prediction PDL data generation unit derives the position coordinates for each block based on the paper size, data resolution, and page direction of the processing target page, and generates a drawing command corresponding to each block from the derived position coordinates. The image processing apparatus according to claim 2, wherein the prediction PDL data is generated.   The prediction PDL data generation unit generates the prediction PDL data using a drawing command corresponding to each block obtained in advance according to a combination of paper size, data resolution, and page direction. The image processing apparatus according to claim 2.   The image processing apparatus according to claim 2, wherein the drawing command corresponding to each block is a clip command for a rectangular object inscribed in each block.   6. The image processing apparatus according to claim 5, wherein the clip command is added before an object drawing command included in the input PDL data from the beginning. The prediction means generates intermediate data from the prediction PDL data, and adds one edge of the pixel data to the number of pixel data generated by the rendering means from the edge height and span number obtained by adding all the edges included in the intermediate data. By multiplying the processing time required for generation, the time required for generating bitmap data in the rendering means is predicted,
The edge is the outline of the object,
The image processing apparatus according to claim 1, wherein the span is a closed region surrounded by the edges in a single scan line. An image forming apparatus having a rendering unit that generates bitmap data divided into a plurality of blocks by block division rendering with respect to input PDL data, comprising the image processing apparatus according to any one of claims 1 to 7,
An image forming apparatus, further comprising: a display unit that displays a value obtained by adding a time required for paper feeding to paper discharge to a time predicted by the prediction unit as a required printing time. A method for predicting a time required for generating bitmap data in an image forming apparatus having a rendering unit that generates bitmap data divided into a plurality of blocks by block division rendering for input PDL data,
Generating prediction PDL data in which correction information for prediction is added to the input PDL data;
Predicting the time required to generate the bitmap data based on correction information included in the intermediate data generated from the prediction PDL data.   A program for causing a computer to function as the image processing apparatus according to any one of claims 1 to 7.