JP4861084B2 - Drawing processing apparatus and control method thereof - Google Patents

Description

  The present invention relates to a drawing process for generating image data according to drawing data such as a page description language (PDL).

  An image forming apparatus such as a printing apparatus includes a drawing processing apparatus that interprets drawing data described in a page description language (PDL) such as PostScript or PDF sent from an input device to form a raster image. Here, the drawing data is configured as a set of a plurality of types of drawing objects, and examples of the types include graphics, text, and other images. The processing of these drawing objects is different from each other, and a lot of processes and time are required for drawing processing of a complicated drawing object.

  Therefore, in order to speed up image output, units having various processing functions are added to the image forming apparatus. Many of these added units are often implemented by hardware. However, while hardware implementation is fast, a circuit scale increases because a dedicated unit is added for each target process. On the other hand, parallelization of drawing processing is performed as another method for speeding up. In such parallelization, the following method is taken. For example, there is a method in which input drawing data is analyzed and divided into drawing objects, and the divided drawing data is distributed to a plurality of drawing processing devices and processed in parallel. Alternatively, there is a method in which drawing data for generating a partial image is reconstructed by dividing the drawing data into regions, and the reconstructed drawing data is distributed to a plurality of drawing processing devices and processed in parallel. .

A configuration in which a dedicated drawing processing apparatus is provided as described above and a drawing object is processed by performing parallel processing is disclosed in Patent Document 1. In Patent Document 1, a dedicated drawing processing unit is provided for each character, image, and drawing figure, and each processing is speeded up and speeded up by parallel execution.
JP 02-063760

  In general, the drawing figure includes a figure constituted by a straight line, a figure originally constituted by a curved line but approximately expressed by a straight line, a figure constituted by a curve expressed by a high-order function, and the like. . The outline tracing processing of these drawing figures must be performed in units of pixels or scanning lines, and the number of operations increases especially as the definition becomes higher, so the processing time of the higher-order function greatly affects the drawing time. . When a plurality of drawing processing devices arranged for parallel processing are dedicated drawing processing devices for each type of drawing object as in Patent Document 1, there is a bias in the types of drawing objects included in the print data. If there is, there is a problem that the effect of parallelization becomes small.

  On the other hand, if all the drawing processing devices arranged for parallel processing can cope with a wide range of drawing objects in order to prevent such a bias, a highly functional drawing processing device is arranged more than necessary. become. For example, it is not necessary that all drawing processing apparatuses arranged for array processing can execute high-order functions at high speed. Rather, such a configuration undesirably increases the performance and cost of hardware.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable drawing processing relating to graphics to be executed at high speed without excessively increasing the circuit scale.

In order to achieve the above object, a drawing processing apparatus according to an aspect of the present invention has the following arrangement. That is,
First and second drawing processing units that execute software for processing a drawing command sequence, and the first drawing processing unit does not have a multiplier, and the second drawing processing unit has a multiplier,
A classification means for extracting a drawing command sequence for each graphic object from the input drawing data, and classifying the extracted drawing command sequence based on whether higher-order function operations are required;
Selection means for the drawing processing unit for processing each of the plurality of drawing instruction sequence, based on the classification result by the classifying means, for selecting from said first and second rendering unit,
Transmitting means for transmitting the drawing command sequence to the drawing processing unit selected by the selecting means;
And a synthesizing means for synthesizing the drawing result generated by processing the drawing instruction sequence transmitted by the first and second rendering processing unit and the transmission unit,
The selecting means includes a multiplier for drawing command sequences that require higher-order function operations so that parallel operations of the first and second drawing processing units are maintained in processing the plurality of drawing command sequences. preferentially assigned to the drawing processing unit having preferentially allocated Ru to the drawing processing unit that high order function calculating has no multiplier unnecessary drawing instruction sequence.

In addition, a drawing processing apparatus according to another aspect of the present invention for achieving the above object has the following configuration. That is,
A plurality of drawing processing units for executing software for processing a drawing command sequence;
A classification means for extracting a drawing command sequence for each graphic object from the input drawing data, and classifying the extracted drawing command sequence based on whether higher-order function operations are required;
When the drawing command sequence is classified as a drawing command sequence that does not require higher-order function operations , the drawing command sequence is transmitted to one of the plurality of drawing processing units, and the drawing command sequence is processed by higher-order function operations. A plurality of drawing processes selected from the plurality of drawing processing units so that each drawing range obtained by dividing the graphic object is processed by another drawing processing unit. Transmitting means for transmitting the drawing command sequence to the unit;
And a synthesizing means for synthesizing the drawing result generated by the plurality of drawing processing section processes the drawing instruction sequence transmitted by the transmission means.

  According to the present invention, it is possible to execute a drawing process on a graphic at a high speed without excessively increasing the circuit scale.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment>
FIG. 1A is a block diagram illustrating a configuration example of an image forming apparatus according to the first embodiment. In the image forming apparatus 1, the input I / F 11 receives print data described in PDL from an external information processing apparatus (for example, a personal computer). The drawing processing apparatus 100 processes the print data to generate a bitmap image. The video signal converting unit 12 converts the bitmap image generated by the drawing processing apparatus 100 into a scanning line sequential video signal and outputs it to the printer engine 13. The printer engine 13 forms a visible image on the recording medium according to the received bitmap image. For the printer engine 13, any known recording method such as an electrostatic photographic method using a laser beam or an ink jet method can be applied. When the image data is supplied to the printer engine 13 in band units when the inkjet method is adopted, a processing unit for writing the image in band units in the band memory is provided instead of the video signal converting unit 12. Become.

  In the above configuration, the drawing processing apparatus 100 receives print data in PDL such as PostScript or PDF, for example, and forms image data based on the PDL. FIG. 1B is a block diagram illustrating a configuration example of the drawing processing apparatus 100 according to the first embodiment.

  In the drawing processing apparatus 100, a command analysis unit 101 inputs print data (PDL) and analyzes a drawing command of the input print data. The command analysis unit 101 extracts a drawing command sequence for each drawing object from such a drawing command sequence. When the print data (drawing data) includes a drawing command sequence for drawing a graphic as will be described later with reference to FIG. 2, the command analysis unit 101 extracts a drawing command sequence for each graphic object. The graphic group determination unit 102 classifies the drawing command sequence corresponding to the graphic object according to the processing capability required to draw the graphic (for example, whether higher-order function calculation is necessary). The drawing command distribution unit 103 distributes the classified drawing command sequence to the first processor 104 and the second processor 105 according to each classification result. Each of the first processor 104 and the second processor 105 is an image processing unit that draws an image in accordance with a drawing command. The pixel composition unit 106 combines the pixel information generated by the first processor 104 and the pixel information generated by the second processor 105 and outputs bitmap data corresponding to the print data. In the present embodiment, only a processor for drawing graphics is shown, but the drawing processing apparatus 100 also has a dedicated processor for drawing characters and images. Or you may comprise so that a character and an image may be drawn with a 1st processor or a 2nd processor. However, since the configurations of these processors and the distribution of drawing commands to these processors are well known, the description thereof is omitted here.

Hereinafter, each configuration will be described in more detail.
The command analysis unit 101 receives print data described in PDL, interprets the print data in accordance with PDL rules, executes a non-render command, and render command sequences (command group) for each rendering object. Has the function of cutting out

  The graphic group determination unit 102 refers to the graphic group correspondence table 400 that defines the correspondence between drawing commands and graphic groups, and the first group that does not require higher-order function operations for each drawing command sequence cut out by the command analysis unit 101 And a second group that requires higher-order function operations. FIG. 4 is a diagram showing a data configuration example of the figure group correspondence table 400. In the graphic group correspondence table 400 shown in FIG. 4, a command “lineto” 401 for drawing a straight line is associated with the first group. A command “arc” 402 for drawing a circle and a command “curveto” 403 for drawing a curve (Bézier curve) are associated with the second group. That is, the first group indicates a figure that can be solved by a linear function, and the second group indicates a figure that requires calculation of a high-order function. For example, when the command “curveto” is included in the drawing command sequence, the graphic group of the drawing command sequence is determined to be the second group. In this way, the graphic group determination unit 102 refers to the graphic group correspondence table 400 to determine whether the drawing command sequence (graphic) belongs to a group (second group) that requires a higher-order function operation when drawing. It is determined whether it belongs to a group (first group) that is not so.

  Based on the group determined by the graphic group determination unit 102, the drawing command distribution unit 103 distributes the drawing command sequence of the corresponding graphic to the first processor 104 as the first drawing command sequence, and distributes it to the second processor 105. It has a function of distributing as a second drawing command sequence. In the present embodiment, the drawing command belonging to the first group is generated as a first drawing command sequence, and the drawing command belonging to the second group is generated as a second drawing command sequence.

  The first processor 104 is a processor having an adder, a logical operator, and a shift operator. The first processor 104 processes the first drawing command sequence distributed by the drawing command distribution unit 103 and executes software for generating a raster image, whereby first bitmap data corresponding to the first drawing command sequence is executed. Is generated. The second processor 105 is a processor having a multiplier in addition to the configuration of the first processor 104. The second processor 105 processes the second drawing command sequence distributed by the drawing command distribution unit 103 and executes software for generating a raster image, thereby generating second bitmap data corresponding to the second drawing command sequence. Is generated. Further, by using a multiplier, high-order function calculation can be processed at high speed.

  The pixel synthesis unit 106 uses the first bitmap data generated by the first processor 104 and the second bitmap data generated by the second processor 105 based on the vertical relationship defined in the print data. Synthesize. The synthesized bitmap data is output from the pixel synthesis unit 106 as bitmap data of an image corresponding to the print data.

  The operation of the drawing processing apparatus 100 according to the present embodiment having the above-described configuration will be described in more detail with reference to drawing examples shown in FIGS.

  FIG. 2 shows an example of print data (drawing instruction sequence) described in the PostScirpt language that is input to the instruction analysis unit 101 shown in FIG. FIG. 3 shows an image drawn by this print data. In FIG. 2, descriptions 201 and 202 correspond to drawing commands for each drawing object, and are drawing command sequences for drawing the triangle object 301 and the curve object 302 shown in FIG. 3, respectively.

  The drawing command indicated by the description 203 in FIG. 2 is a part that defines the shape of a graphic to be drawn. The description 203 defines the shape of the triangle object 301. More specifically, first, the pen coordinates are moved to (X, Y) = (180, 280) by a moveto command. Then, a straight line is drawn to the coordinates (120, 70), (315, 170), (180, 280) in order by the lineto command, and the triangle object 301 is drawn. In the description 203, only lineto appears until closepath. Therefore, the graphic group determining unit 102 refers to the graphic group correspondence table 401 shown in FIG. 4 and determines that the graphic drawn by the description 203 belongs to the first group requiring only the calculation of the linear function. If curve 203 or the like is included in the description 203, it is determined that the graphic drawn in the description 403 is a graphic belonging to the second group. This determination result (group information indicating that it belongs to the first group) is input to the drawing command distribution unit 103 together with the drawing command sequence of the description 203. The drawing command distribution unit 103 outputs, to the first processor 104, a drawing command sequence that reaches the descriptions 203 to 205 based on the group information indicating the first group.

  The first processor 104 processes a drawing command sequence extending from the descriptions 203 to 205. Since a difference calculation is usually performed for each coordinate for a linear function, an adder is sufficient for a table calculation. A description 204 (setrgbcolor) defines the color of the triangle defined in the description 203. Here, red is designated. The description 205 is instructed to fill the triangle defined in the description 204 with the red color. Therefore, the first processor 104 outputs pixel data indicating red for the pixels corresponding to the coordinates included in the triangle defined by the description 203.

  A description 206 in FIG. 2 instructs to draw a curved object 302 (Bézier curve). Here, first, the coordinates of the pen are moved to (30, 20), and a Bezier curve surrounded by the current pen coordinates and four points (85, 120), (160, 60), and (140, 20) is drawn. Since the line following description 206 is not defined, it can be seen that this is a single Bezier curve.

  The graphic group determination unit 102 refers to the graphic group correspondence table 400 shown in FIG. 4 and determines that the graphic of the description 206 belongs to the second group that requires the calculation of a higher-order function.

  This determination result (group information indicating that it belongs to the second group) is input to the drawing command distribution unit 103 together with the drawing command sequence of the description 202. The drawing command distribution unit 103 outputs the drawing command sequence of the description 202 to the second processor 105 in accordance with the group information indicating the second group.

  The second processor 105 processes the drawing command sequence of the description 202. Since the calculation of the high-order function requires multiplication, the second processor 105 has a configuration for executing multiplication at high speed. The second processor 105 outputs pixel data indicating red for the pixel corresponding to the coordinates of the Bezier curve defined by the description 206. The drawing command distribution unit 103 adds the description 204 to the description 202 and transmits the description 202 to the second processor 105 because no color is specified in the description 202. Therefore, the color of the Bezier curve drawn by the description 206 is the color set by the description 204.

  The pixel synthesizing unit 106 synthesizes the first bitmap data output from the first processor 104 and the second bitmap data output from the second processor 105 as described above, as bitmap data for the input print data. Output this. When the triangle object 301 and the curve object 302 overlap in the print data of FIG. 2, the pixel composition unit 106 performs the following process. That is, the pixel composition unit 106 includes the first bitmap data and the first bitmap data so that the triangle object 301 corresponding to the description 203 that appears first in the drawing command sequence is overwritten by the curve object 302 corresponding to the description 206 that appears later. The second bitmap data is synthesized.

  As described above, according to the first embodiment, graphics included in print data are assigned to processors having different configurations depending on whether or not higher-order functions need to be calculated for drawing, and are processed in parallel.

  The drawing command distribution unit 103 has a schedule function for assigning drawing of graphics belonging to the second group to the first processor 104 when drawing processing of some figures has already been assigned to the second processor 105. It may be allowed. Similarly, the drawing command distribution unit 103 has a scheduling function for assigning drawing of graphics belonging to the first group to the second processor 105 when drawing processing of some graphics has already been assigned to the first processor 104. You may have it. That is, the rendering command distribution unit 103 preferentially assigns a rendering command sequence that requires a higher-order function operation to a processor having a multiplier, and prioritizes a rendering instruction sequence that does not require a higher-order function operation to a processor that does not have a multiplier. May be assigned automatically. In this way, parallelism can be more effectively maintained even when there is a bias in the graphics that appear in the page.

  In the above embodiment, the bitmap data is generated by the first processor 104 and the second processor 105, but the present invention is not limited to this. For example, the present invention can be applied to a configuration in which the first processor 104 and the second processor 105 calculate only the intersection coordinates of each figure for each scanning line. The configuration and operation of the image composition unit 106 in this case will be described with reference to FIG.

  The image composition unit 106 has an image processing pipeline 72 that generates image data for each scanning line with reference to a display list 71 including an instruction stream obtained from the calculation results of the first processor 104 and the second processor 105 and print data. . In the display list 71, an instruction stream 711 is a drawing instruction stream acquired from print data. Edge information 712 is information of intersection coordinates of each figure for each scanning line acquired from the first processor 104 and the second processor 105.

The pixel composition unit 106 includes an image processing pipeline 72. The image processing pipeline 72 includes an instruction processing unit 721, an edge processing unit 722, a priority order determination unit 723, a fill color determination unit 724, a pixel generation unit 725, and a pixel output unit 726. The units 721 to 726 are connected in series.
The instruction processing unit 721 interprets the instruction stream 711 in the display list 71, converts the instruction into a format suitable for each downstream unit, and sends it out. The edge processing unit 722 scans the scan lines and sorts the intersection coordinates of the edge information 712 in the display list 71. That is, the edge processing unit 722 receives the intersection coordinate coordinates of the graphics from the first processor 104 and the second processor 105 for each scanning line, sorts the received coordinates in the order of the scanning line direction coordinates, and generates edge intersection information. . Then, the edge processing unit 722 sends the edge crossing information and the scan line end information to the downstream image processing unit together with the priority order information and the fill information received from the instruction processing unit 721.

  Based on the edge intersection information and the priority order information, the priority order determination unit 723 determines a valid figure at each position on the scanning line from the correspondence between the intersection coordinates and the figure, and generates valid figure information. That is, the priority order determining unit 723 refers to the correspondence between the intersection coordinate sequence rearranged by the above sort processing and the figure, and the figure activated as the drawing target figure in the scanning line (the figure priority order ( That is, the vertical relationship)) is determined and used as effective graphic information. Then, the priority order determination unit 723 sends the effective graphic information to the fill color determination unit 724 together with the fill information and the scan line end information received from the upstream edge processing unit 722.

  The fill color determination unit 724 determines the color of each pixel on the scanning line based on the effective graphic information and the fill information, and generates color composition information. In other words, the fill color determination unit 724 determines the figure related to the color of the pixel from the vertical positional relationship (effective figure information) of the activated figure and the color transparency information (fill information), and determines the color of each figure. To decide. That is, the colors represented according to the color information of each figure are synthesized according to the vertical positional relationship of the figure, the color of each pixel on the scanning line is determined, and this is used as the color synthesis information. The fill color determination unit 724 sends the generated color composition information, pixel end information, and scan line end information to the pixel generation unit 725. The pixel generation unit 725 generates a pixel of the scanning line from the received information and sends it to the pixel output unit 726. The pixel output unit 726 outputs the pixel data received from the pixel generation unit 725 to the printer or the like as bitmap data. As described above, the pixel synthesizing unit 106 synthesizes the colors of the figure effective for the pixel or the pixel span on the scanning line and outputs the bitmap data in the pixel coordinate order.

  In addition, the first embodiment includes a plurality of processors having different processing capabilities, and the drawing command distribution unit 103 draws the drawing from the plurality of processors according to the calculation capability necessary for processing the drawing command sequence corresponding to the graphic object. Select a processor to process the instruction sequence. Therefore, although FIG. 1B shows an example in which two processors are provided as processors for drawing a graphic object, the number of processors is not limited to this.

  As described above, according to the first embodiment, the graphics included in the PDL are assigned to processors having necessary and sufficient functions and processed in parallel, thereby reducing the drawing time without excessive increase in circuit scale. be able to.

Second Embodiment
In the first embodiment, a configuration is shown in which a plurality of processors having different capabilities are prepared and a drawing command is distributed to one of the plurality of processors according to the calculation capability necessary for executing the drawing command. In the second embodiment, a plurality of processors having the same capability are prepared, and for drawing commands that require high processing power (drawing commands that require processing time), the graphic object to be drawn is divided and shared by the plurality of processors. One graphic object is drawn.

  FIG. 5 is a block diagram illustrating a configuration example of a drawing processing apparatus 500 according to the second embodiment. A configuration example of an image forming apparatus to which the drawing processing apparatus 500 can be applied is as shown in FIG. 1A. In the second embodiment, the drawing processing apparatus 500 is arranged instead of the drawing processing apparatus 100. .

  In FIG. 5, the instruction analysis unit 101, the figure group determination unit 102, and the figure group correspondence table 400 have the same configuration as that of the first embodiment (FIG. 1B). The drawing command distribution unit 503 distributes a drawing command sequence corresponding to the graphic object to the processors 501a to 501c based on the group information determined by the graphic group determination unit 102. In the second embodiment, the plurality of processors 501a to 501c, which are image processing units, all have the same drawing processing capability (however, there may be a difference in processing capability between the plurality of processors). . The pixel synthesis unit 504 merges the pixel information generated by the processors 501a to 501c to generate bitmap data, and outputs this as bitmap data corresponding to the print data.

  As described above, the graphic group determination unit 102 uses the drawing command sequence for the first group of graphic objects that do not require higher-order function operations and the second group of graphic objects that require higher-order function operations. Are divided into drawing command sequences. The graphic group determination unit 102 provides the drawing command sequence to the drawing command distribution unit 503 together with group information indicating which of the first group and the second group belongs. The drawing command distribution unit 503 sets the drawing command sequence of the first group of graphic objects as the first drawing command sequence, and sets the drawing command sequence of the second group of graphic objects that require higher-order function operations as the second drawing command sequence. To do. The drawing distribution unit 503 distributes the first drawing instruction sequence to a single processor (for example, the processor 501a) among the processors 501a to 501c, and distributes the second drawing instruction sequence to a single processor or a plurality of processors (for example, the processor 501b). , 501c).

  The processors 501a to 501c are processors each having an adder, a logical operation unit, and a shift operation unit, and execute software for processing a drawing command sequence distributed by the drawing command distribution unit 503 to generate a raster image. In this way, the first bitmap data corresponding to the first drawing instruction sequence and the second bitmap data corresponding to the second drawing instruction sequence are generated by the processors 501a to 501c. The pixel synthesis unit 504 synthesizes the first bitmap data and the second bitmap data generated by the processors 501a to 501c based on the vertical relationship defined in the print data, and the image bits corresponding to the print data. It has a function to output map data.

Hereinafter, as in the first embodiment, the detailed operation of the image forming apparatus according to the second embodiment will be described in the case of drawing the graphic shown in FIG. 3 in accordance with the drawing command shown in FIG.
The process until the description 201 is classified into the first group drawing command sequence and the description 202 is classified into the second group drawing command sequence by the command analysis unit 101 and the graphic group determination unit 102 is the same as in the first embodiment. is there.

  The drawing command distribution unit 503 distributes a drawing command sequence for one graphic object classified into the first group to a single processor. For example, a drawing command sequence (description 201) corresponding to one triangle object 301 is supplied to the processor 501a, and a triangle is drawn according to the procedure described in the first embodiment.

  On the other hand, regarding the drawing command sequence for one graphic object classified into the second group, it is determined whether or not the size of the graphic falls within a predetermined drawing range (for example, the size in the scanning line direction). In this case, it is distributed to a plurality of processors together with the drawing range designation. In this case, the figure is divided in a predetermined drawing range, and a drawing command sequence is sent to a plurality of processors together with the drawing range specification so that the divided parts are drawn by different processors. If it falls within the predetermined drawing range, a drawing command sequence is sent to a single processor. In other words, the number of processors equal to the number of divisions is assigned to draw one graphic object. If the number of divisions exceeds the number of processors provided, for example, the graphic object may be divided by the number of processors. Or you may make it make a processor process a some division | segmentation part. For example, when a graphic object divided into five is executed by three processors, two divided parts may be distributed to two processors so that one processor processes one divided part. . In the case of the present embodiment, when the size of the graphic object is within a predetermined drawing range, even a drawing command sequence classified into the second group is processed by a single processor. Note that the method of dividing the graphic objects classified into the second group is not limited to this, and various modifications are possible, for example, dividing into a predetermined number.

  The processors 501a to 501c execute a drawing process by executing the inputted drawing command sequence. When the drawing range is specified, the drawing process is performed within the specified range. When executing the second group of drawing commands, it is necessary to calculate a high-order function with multiplication, so that the multiplication needs to be executed at high speed. In the first embodiment, a high-speed processor is used to cope with such a drawing command. However, in the second embodiment, the drawing range is reduced and parallel processing is performed by a plurality of processors, thereby drawing the second group. The drawing process by the command is executed at high speed.

  For example, the curve object 302 indicated by the description 202 is divided into two parts A and B as shown in FIG. 6, and the parts A and B are drawn in parallel by two processors. This can be realized by changing the parameter in “curveto” of the description 206 to generate a drawing command for drawing only the part A and a drawing command for drawing only the part B, and sending them to different processors. Alternatively, in the case of an instruction system that can add a command indicating a drawing range, such a drawing range designation command may be added to send a drawing command sequence to each processor.

  The pixel synthesizing unit 504 synthesizes the bitmap data input from the plurality of processors 501a to 501c and outputs the synthesized bitmap data to the outside as bitmap data for the print data. In the case of the above example, the bitmap data including the triangle object 301, the bitmap data including the part A of the curve object 302, and the bitmap data including the part B of the curve object 302 are combined, and the bit as shown in FIG. Map data is generated.

When the triangle 203 and the curve 206 overlap in the print data of FIG. 2, the pixel composition unit 504 performs the following process. That is, the pixel synthesis unit 504 synthesizes the bitmap data so that the triangle object 301 corresponding to the description 203 that appears first in the drawing command sequence is overwritten by the curve object 302 corresponding to the description 206 that appears later. .

  As described above, in the second embodiment, graphics included in print data are assigned to different numbers of processors and processed in parallel depending on whether or not higher-order functions need to be calculated for drawing. In other words, the drawing process can be performed at high speed by sharing the drawing of one figure by a plurality of processors according to the weight of the drawing process and efficiently executing the parallel processing.

  The second embodiment shown in FIG. 5 can be applied to an embodiment in which only the intersection coordinates of each figure are calculated for each scanning line in the processors 501a to 501c. In this case, the configuration of the image processing pipeline 72 described above with reference to FIG. That is, the pixel composition unit 504 receives coordinate data for each scanning line from the plurality of processors 501a to 501c for each scanning line, and sorts the coordinate data in the order of the scanning line direction coordinates. Then, the effective figure on the scanning line is determined from the correspondence between the intersection and the figure, and the pixel color on the scanning line or the color of the figure that is valid for the span of the pixel from the pixel is synthesized, and the bitmap is in the pixel coordinate order. Output data.

  Although FIG. 5 shows three processors, the present invention is not limited to this. Moreover, you may combine the structure of 1st Embodiment and 2nd Embodiment. For example, a plurality of first processors and second processors are provided, drawing command sequences classified into the first group are distributed preferentially to the first processor, and drawing command sequences classified into the second group It is preferentially distributed to two processors. Then, when a situation in which the first processor executes the second group of drawing instruction sequences due to the usage status of the second processor, the second group of drawing instruction sequences is executed by a plurality of first processors.

  As described above, according to the second embodiment, a drawing process is assigned to a single or a plurality of processors in accordance with the respective computation loads, and a graphic included in the PDL is processed in parallel. For this reason, the drawing time can be shortened without excessive increase in circuit scale.

1 is a diagram illustrating a configuration example of an image forming apparatus according to a first embodiment. It is a figure which shows the structural example of the drawing processing apparatus by 1st Embodiment. It is a figure which shows the example of a drawing command by PostScript. It is a figure which shows the image drawn by the drawing command of FIG. It is a figure which shows the example of a data structure of a figure group corresponding | compatible table. It is a figure which shows the structural example of the drawing processing apparatus by 2nd Embodiment. FIG. 3 is a diagram illustrating image division in an image drawn by the drawing command of FIG. 2. It is a block diagram explaining the structure of the pixel synthetic | combination part which performs a pixel synthesis | combination based on the intersection coordinate from a processor.

Claims (11)

First and second drawing processing units that execute software for processing a drawing command sequence, and the first drawing processing unit does not have a multiplier, and the second drawing processing unit has a multiplier,
A classification means for extracting a drawing command sequence for each graphic object from the input drawing data, and classifying the extracted drawing command sequence based on whether higher-order function operations are required;
Selection means for the drawing processing unit for processing each of the plurality of drawing instruction sequence, based on the classification result by the classifying means, for selecting from said first and second rendering unit,
Transmitting means for transmitting the drawing command sequence to the drawing processing unit selected by the selecting means;
And a synthesizing means for synthesizing the drawing result generated by processing the drawing instruction sequence transmitted by the first and second rendering processing unit and the transmission unit,
The selecting means includes a multiplier for drawing command sequences that require higher-order function operations so that parallel operations of the first and second drawing processing units are maintained in processing the plurality of drawing command sequences. assigned to the drawing processing unit preferentially with, drawing processing apparatus according to claim preferentially assign to the drawing processing unit that high order function calculating has no multiplier unnecessary drawing instruction sequence. Each of the first and second drawing processing units generates a bitmap image of a figure drawn as the drawing result,
The synthesizing unit is configured so that a bitmap image as a rendering result generated by the first and second rendering processing units is a vertical positional relationship between overlapping bitmap images determined based on the input rendering data. The drawing processing apparatus according to claim 1, wherein the image processing is performed according to the following. Each of the first and second drawing processing units generates, as a drawing result, an intersection between the drawn graphic object and the scanning line for each scanning line for forming a visible image,
The synthesizing unit sorts intersections on the same scanning line acquired from the first and second drawing processing units in order of scanning line direction coordinates for each scanning line, and is determined based on the input drawing data . The drawing processing apparatus according to claim 1, wherein intersections and pixel values between the intersections are determined according to a vertical positional relationship between overlapping bitmap images as drawing results . A plurality of drawing processing units for executing software for processing a drawing command sequence;
A classification means for extracting a drawing command sequence for each graphic object from the input drawing data, and classifying the extracted drawing command sequence based on whether higher-order function operations are required;
When the drawing command sequence is classified as a drawing command sequence that does not require higher-order function operations , the drawing command sequence is transmitted to one of the plurality of drawing processing units, and the drawing command sequence is processed by higher-order function operations. A plurality of drawing processes selected from the plurality of drawing processing units so that each drawing range obtained by dividing the graphic object is processed by another drawing processing unit. Transmitting means for transmitting the drawing command sequence to the unit;
Drawing processing apparatus, characterized in that it comprises a synthesizing means for synthesizing the drawing result generated by the plurality of drawing processing section processes the drawing instruction sequence transmitted by the transmission means. The transmission unit, based on the size of the graphic object drawn by the drawing instruction sequence which requires a high-order function to determine the number of drawing processing unit for processing the drawing instruction sequence, the higher the drawing instruction sequence 5. The drawing processing apparatus according to claim 4, wherein when the drawing command sequence is classified into a drawing command sequence requiring a next function operation, the drawing command sequence is transmitted to the determined number of drawing processing units. Each of the plurality of drawing processing units generates a bitmap image of a figure drawn as the drawing result,
The synthesizing unit synthesizes a bitmap image as a drawing result generated by the plurality of drawing processing units according to a vertical positional relationship between overlapping bitmap images determined based on the input drawing data. The drawing processing apparatus according to claim 4. Each of the plurality of drawing processing units generates, as a drawing result, an intersection of a drawn figure and a scanning line for each scanning line for forming a visible image,
The synthesizing unit sorts the intersections acquired from the plurality of drawing processing units in order of scanning line direction coordinates for each scanning line, and determines bitmap images as drawing results determined based on the inputted drawing data. The drawing processing apparatus according to claim 4, wherein the intersection and the pixel value between the intersections are determined according to a vertical positional relationship of the overlaps . A control method of a drawing processing apparatus having first and second drawing processing units for executing software for processing a drawing command sequence, wherein the first drawing processing unit does not have a multiplier, and The drawing processing unit has a multiplier,
A classifying step in which the classifying means extracts a drawing command sequence for each graphic object from the input drawing data, and classifies the extracted drawing command sequence based on whether a higher-order function operation is required;
Selection means, a selection step of a drawing processing unit for processing each of the plurality of drawing instruction sequence, based on the classification result of the drawing instruction sequence by the classification process, selecting from said first and second drawing processing unit ,
A transmission step of transmitting the drawing command sequence to the drawing processing unit selected in the selection step;
A synthesizing unit that synthesizes a drawing result generated by the first and second drawing processing units processing the drawing command sequence transmitted in the transmitting step ;
In the selection step, when processing the plurality of drawing command sequences, a multiplier is applied to the drawing command sequence that requires a higher-order function operation so that the parallel operation of the first and second drawing processing units is maintained. preferentially assigned to the drawing processing unit having a method of controlling a drawing processing apparatus according to claim preferentially assign to the drawing processing unit that high order function calculating has no multiplier unnecessary drawing instruction sequence. Each of the first and second drawing processing units generates, as a drawing result, an intersection between the drawn graphic object and the scanning line for each scanning line for forming a visible image,
  In the synthesis step, for each scanning line, the intersection points on the same scanning line acquired from the first and second drawing processing units are sorted in order of scanning line direction coordinates, and determined based on the inputted drawing data. 9. The method according to claim 8, wherein the intersections and pixel values between the intersections are determined in accordance with a vertical positional relationship between overlapping bitmap images as rendering results. A control method of a drawing processing apparatus having a plurality of drawing processing units for executing software for processing a drawing command sequence,
A classifying step in which the classifying means extracts a drawing command sequence for each graphic object from the input drawing data, and classifies the extracted drawing command sequence based on whether a higher-order function operation is required;
If the drawing command sequence is classified as a drawing command sequence that does not require higher-order function operations , the transmitting means transmits the drawing command sequence to one of the plurality of drawing processing units, and the drawing command sequence is When it is classified into a drawing command sequence that requires higher-order function calculation, it is selected from the plurality of drawing processing units so that each drawing range obtained by dividing the graphic object is processed by another drawing processing unit. A transmission step of transmitting the drawing command sequence to a plurality of drawing processing units;
A method for controlling a drawing processing apparatus, characterized in that: a combining unit includes a combining step of combining drawing results generated by the plurality of drawing processing units processing the drawing instruction sequence transmitted in the transmitting step. . Each of the plurality of drawing processing units generates, as a drawing result, an intersection of a drawn figure and a scanning line for each scanning line for forming a visible image,
In the synthesizing step, for each scanning line, the intersection points acquired from the plurality of drawing processing units are sorted in order of scanning line direction coordinates, and bitmap images as drawing results are determined based on the inputted drawing data. The method according to claim 10, wherein the intersection and the pixel value between the intersections are determined according to a vertical positional relationship of the overlaps.

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