JP2008107970A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device in which its output speed is accelerated by efficiently deleting graphic data to be included by combinations of a plurality of graphics. <P>SOLUTION: The image forming device comprises: a PDL analysis part 12 for analyzing prescribed data to extract the graphic data and their area data; a display list creation part 14 for successively creating one or more graphic data and their area data extracted as a display list; a display list deletion part 15 for deleting the display list of the extracted graphic when the graphic area extracted earlier is included in areas of the plurality of graphics extracted later; and a page rasterizing part 16 for outputting image forming data on the basis of the graphic data composing the display list. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of effectively shortening a drawing processing time.

Conventionally, various researches on image processing technology have been continuously carried out. One of them has been research on high-speed processing technology of image forming apparatuses such as printers and scanners.
In particular, in recent years, the amount of data processing handled has greatly increased due to colorization of output and multi-gradation, and further speeding-up of image processing is required.

For this reason, an image processing apparatus has been proposed that aims to improve the bit map conversion speed by reducing the storage area of the intermediate list (for example, Patent Document 1).
According to this image processing apparatus, as shown in FIG. 14, when the drawing area of the first graphic 701 drawn first is included in the drawing area of the second graphic 702 drawn later, The data of the first graphic 701 is deleted from the intermediate list to increase the speed.
In addition, when the drawing area of the first graphic and the drawing area of the second graphic overlap, the speed is also increased by deleting the overlapping portion from the first graphic.

JP 2001-88367 A (first page, FIG. 1)

However, in the conventional image processing apparatus as described above, the first graphic data can be directly deleted when the first graphic is included by the subsequent graphic. However, when the first graphic is included by a plurality of subsequent graphics, the first graphic data is not deleted directly, but the first graphic is only deleted by deleting the number of overlapping portions. All data can be deleted.
Therefore, when the first graphic is included by a large number of graphics, the number of processes required for data deletion is greatly increased.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and it is possible to speed up output by efficiently deleting graphic data included in a combination of a plurality of graphic elements. An object of the present invention is to provide an image forming apparatus capable of achieving the above.

  In order to achieve the above object, an image forming apparatus according to the present invention, as described in claim 1, analyzes predetermined data and extracts data for extracting graphic data and its area data. When the graphic data and the display list for sequentially storing the graphic data and the previously stored graphic area are included in the single graphic area stored later, the previously stored graphic Including graphic deletion means for deleting the data of the display list from the display list, output means for outputting image formation data based on the graphic data stored in the display list, and the first stored in the display list An overlapping area detecting means for detecting an overlapping area between the area of the graphic and the area of the second graphic stored later; and The area changing means for changing to the divided area and the inclusion graphic deleting means are configured such that the area of the first graphic changed by the area changing means is changed to a graphic area other than the second graphic stored later. When included, the first graphic data is deleted from the display list.

According to the image forming apparatus of the present invention having such a configuration, an overlapping area between figures to be drawn is obtained, and the overlapping area is deleted from the area of the original figure.
Then, based on the area of the graphic from which the overlapping area is deleted, when this reference area is included in another graphic, the graphic is deleted, and unnecessary drawing data is deleted.
Therefore, as a result, the graphic data can be deleted not only in the case where one graphic is included only by another single graphic as in the prior art, but also when the graphic is included by a combination of a plurality of graphics.
Further, since the process leading to the deletion of the graphic data is a simple process that controls only the area data as a reference, it is possible to greatly reduce the processing load. Therefore, unnecessary graphic data can be effectively deleted, and image processing efficiency and processing speed can be improved.

  According to a second aspect of the present invention, there is provided an image forming apparatus comprising: a maximum rectangular area calculating unit that calculates a maximum rectangular area of a figure based on the area data; and a bounding box of the figure based on the area data. A bounding box area calculating means for calculating an area, wherein the overlapping area detecting means in the display list includes a bounding box area of the first figure stored earlier and a maximum rectangle of the second figure stored later. An overlapping area with the area is detected, the area changing means changes the bounding box area of the first graphic to the area from which the overlapping area has been deleted, and the inclusion graphic deleting means is changed by the area changing means. The bounding box area of the first figure is the largest rectangular area of the figure other than the second figure stored later When encompassed, certain data of the first figure so as to be deleted from the display list.

According to the image forming apparatus of the present invention having such a configuration, the above-described maximum rectangular area and bounding box area are obtained, and each process is performed by regarding these as a figure area.
Specifically, an overlapping area between the bounding box area of the first graphic to be drawn and the maximum rectangular area of the second graphic is obtained, and the overlapping area is deleted from the bounding box area of the first graphic.
Then, based on the bounding box area after the overlapping area is deleted, when this reference area is included in the maximum rectangular area of another figure, the figure is deleted and unnecessary drawing data is deleted. I am doing so.
Therefore, even if the drawing target is a complicated figure, it is possible to greatly reduce the burden on the calculation process by replacing it with a simple rectangular area that can be approximated. Can do.
Thereby, it is possible to further improve the efficiency and speed of the image processing.

  In the image forming apparatus of the present invention, the area data is constituted by at least predetermined coordinate data.

According to the image forming apparatus of the present invention having such a configuration, it is possible to extract the area of the graphic to be drawn based on the coordinate data, so that the graphic position can be recognized quickly.
Thereby, more efficient and high-speed processing can be performed.
In particular, it is possible to quickly and easily cope with various arithmetic processes such as calculation of the bounding box area and the maximum rectangular area, detection of inclusion / duplication between figures, and area data change processing.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus comprising: a band area generating unit that divides a page frame, which is an output unit, based on a predetermined standard and generates a plurality of band areas; The extraction means analyzes predetermined data, extracts graphic data and its area data for each band area, and the display list sequentially extracts the one or more extracted graphic data and its area data for each band area. It is configured to store.

According to the image forming apparatus of the present invention having such a configuration, a page frame on which a graphic to be rendered is developed is divided into a plurality of band areas, and the so-called band that performs image processing of the present invention for each band area. Processing (or banding processing) can be used in combination.
For this reason, image formation data can be output sequentially in band areas without waiting for completion of output in pages. Therefore, not only memory saving but also faster printing such as shortening the first print time can be achieved. Can do.

According to the image forming apparatus of the present invention, unnecessary graphic data included by a combination of a plurality of graphics to be drawn can be deleted based on a simple control process, and the image processing speed can be effectively improved.
In particular, the processing can be simplified by using the maximum rectangular area and the bounding box area of the figure, and the speed can be further increased by using the band processing together.

A preferred embodiment of an image forming apparatus according to the present invention will be described below with reference to FIGS.
Here, the image forming apparatus of the present embodiment described below is realized by processing, means, and functions executed by a computer according to instructions of a program (software). The program sends a command to each component of the computer to perform predetermined processing and functions as shown below. That is, each process / means in the image forming apparatus of the present embodiment is realized by specific means in which a program and a computer cooperate.
Note that all or part of the program is provided by, for example, a magnetic disk, optical disk, semiconductor memory, or any other computer-readable recording medium, and the program read from the recording medium is installed in the computer and executed. The The program can also be loaded and executed directly on a computer through a communication line without using a recording medium.

[First embodiment]
First, a page printer which is a first embodiment of an image forming apparatus according to the present invention will be described with reference to FIGS.
FIG. 1 is an explanatory diagram for explaining the principle of drawing processing in the page printer according to this embodiment, and FIG. 2 is an explanatory diagram for explaining a display list used in the page printer according to this embodiment. .

In the page printer of this embodiment, first, as shown in FIG. 1A, it is assumed that a target graphic 101 is extracted from received print data.
Subsequently, it is assumed that a figure 102 having a shape partially covering the figure 101 is extracted (FIG. 1B).
Finally, the graphic 103 is extracted, and as a result, the graphic 101 is completely hidden by the graphic 102 and the graphic 103 (FIG. 1C).

For this reason, although the graphic 101 is not reflected in the actual output image, it remains a target for drawing processing in the internal processing of a general page printer.
In this way, the page printer according to the present embodiment has no inclusion relationship in the mutual relationship with the graphic 102 and the graphic 103, and even when there is an overlapping relationship, the graphic 102 and the graphic 103 are combined to form a graphic. When 101 is included, the graphic 101 is deleted from the display list to improve processing efficiency and speed.

Here, the display list is a data table for creating and storing intermediate codes once divided into simple figures before rasterizing received print data in the drawing function of the printer. It has data such as position coordinates, width, and height necessary for.
As a display list storage method, a method of sequentially connecting received drawing data in a list structure is generally employed. Therefore, on the list, the previous data is old, and the data connected later is newer.

In other words, if the position of a certain figure on the page plane is completely covered and hidden by the area of another figure, the figure to be drawn later will be drawn on the previous figure. Since the previous figure does not need to be drawn, the waste of the drawing process can be eliminated by deleting the previous figure.
For example, when the display lists are connected as shown in FIG. 2A, when all the graphics 202 connected as the display list are included by the (n + 1) th and subsequent graphics, the display list is shown in FIG. In this manner, unnecessary data processing can be omitted by deleting the graphic 202.

Next, the configuration and mechanism of the page printer according to the first embodiment of the present invention will be described with reference to FIGS.
FIG. 3 is a block diagram showing a basic configuration of the page printer according to the present embodiment.
The print data reception storage unit 11 buffers print data received from a host computer (not shown) in a storage medium such as a memory.
The PDL analysis unit 12 analyzes the received print data using an emulator and performs appropriate processing. Specifically, graphic data to be drawn and its coordinate data are extracted from the print data by the data extraction means.
The display list creating unit 13 sequentially creates and stores graphics divided into simple shapes as a display list for efficient page rasterization.

The display list information correcting unit 14 detects when a certain figure overlaps another figure in the display list (overlapping area detecting means), and corrects the coordinate data of the figure so as to remove the overlapping part of the underlying figure. (Region changing means).
For example, as shown in FIG. 4A, there is a figure 101 to be drawn first, and vertex A (x1, y1) and vertex B (x2, y2) are extracted as coordinate data indicating the rectangular area. Shall.
Here, as shown in FIG. 4B, when the figure 102 that overlaps a part of the figure 101 is extracted, the display list information correction unit 14 uses the vertex among the coordinate data of the original figure 101. A (x1, y1) is changed to the vertex C (x1 ′, y1 ′).

The display list deletion unit 15 also supports correction of coordinate data by the display list information correction unit 14, and when a certain figure is considered to be completely hidden by another figure, there is no need to draw. The figure data is deleted from the display list (included figure deletion means).
That is, in the case of the above-described example, when the area 111 composed of the vertex C (x1 ′, y1 ′) and the vertex B (x2, y2) is hidden by another graphic, the data of the original graphic 101 Is to be deleted from the display list.
The page rasterizing unit 16 generates a bitmap of graphic data stored in the display list after unnecessary graphic data is deleted by the display list generating unit 13 or deleted by the display list deleting unit 15 and outputs the bitmap. Yes (output means).

As described above, according to the page printer of this embodiment, by detecting the overlap of each figure and changing the coordinate data (region data), the data of the figure hidden by the plurality of figures is deleted. is there.
In other words, even if each figure is relatively partially overlapped, if the target figure is included by a combination of other multiple figures, it is controlled to be excluded from the drawing target. ing.

For this reason, useless drawing target data can be deleted as much as possible, and the drawing processing speed can be improved.
In addition, since the control process is a simple mechanism, the processing load is small, and the page printer according to the present embodiment can be realized by performing the necessary minimum modifications in the existing apparatus. It is.
Accordingly, it is possible to easily realize and provide an image forming apparatus which is improved in processing efficiency and speeded up and is excellent in versatility and expandability.

[Second Embodiment]
Next, a page printer according to a second embodiment of the image forming apparatus of the present invention will be described with reference to FIGS.
FIG. 5 is an explanatory diagram for explaining the principle of drawing processing in the page printer according to the second embodiment of the present invention, and FIG. 6 is for explaining the maximum rectangular area used in the page printer according to the present embodiment. It is explanatory drawing of.
In the present embodiment, the bounding box area and the maximum rectangular area are handled as a graphic area and necessary control is performed.
First, the bounding box area and the maximum rectangular area will be described.

As shown in the left diagram of FIG. 5A, the bounding box area refers to a minimum rectangular area 302 that circumscribes the graphic 301, and refers to a minimum box that includes the target graphic.
On the other hand, the maximum rectangular area refers to the maximum rectangular area 304 inscribed in the figure 303, as shown in the right figure of FIG. 5A. In other words, the two parallel sides of the figure and the sides perpendicular to those sides. A rectangular area formed by lines.

As an actual method of obtaining the maximum rectangular area, first, it is examined whether there are two sides parallel to the horizontal direction. For example, in the case of the graphic shown in FIG. 6, the coordinates of the vertices 1 to 4 are examined, and the presence or absence of parallel sides can be determined based on whether there are two points having the same y-coordinate value.
Specifically, when searching for a vertex equal to the y-coordinate value of vertex 1, vertex 4 is applicable, so a side (vertex 1-vertex 4) is extracted as a horizontal side. Similarly, edges (vertex 2 -vertex 3) are extracted.
Next, it is determined whether or not each side extracted as described above intersects with a perpendicular from each vertex of the side, and an intersection (intersection 5 and intersection 6) in the case of intersecting is detected.
In this way, the maximum rectangular area (hatched portion in FIG. 6) composed of vertex 2 -vertex 3 -intersection point 5 -intersection point 6 can be obtained.

As for the maximum rectangular area, the maximum rectangular area is obtained when the target figure is a trapezoid as shown in FIG. 5C, but the inscribed rectangle is not obtained for a figure having no rectangular portion inside. In this embodiment, the maximum rectangular area is excluded.
That is, a figure that does not have two lines (sides) parallel to the horizontal direction or the vertical direction or a figure that cannot create a rectangle by a line perpendicular to two parallel lines (sides) does not calculate the maximum rectangular area. The maximum rectangular area is also obtained for a figure that cannot be a rectangle including two parallel sides as shown in FIG. 5D or a figure that is a triangle (b) whose one side is 0 (zero) as shown in FIG. 5E. Not applicable.
In actual processing, it is possible to suppress the occurrence of the figure by the division method performed in advance, and even if it occurs, the error is slight. This is because there are very few disadvantages.

The positional information of the bounding box area and the maximum rectangular area obtained in this way is stored in advance in a memory or the like, and is used for detecting an overlap of trapezoids other than rectangular figures.
Specifically, it is determined whether or not the bounding box area of the display list that has been created previously overlaps the maximum rectangular area of the display list graphic that is currently created.

For example, as shown in FIG. 5B, the overlapping of the bounding box area 302 of the triangle 301 and the maximum rectangular area 304 of the trapezoid 303 is determined, and if it overlaps, the vertex B (x2, y2) of the bounding box area To the vertex D (x2 ′, y2 ′).
When the rectangular area including the vertex A (x1, y1) and the vertex D (x2 ′, y2 ′) is included in another graphic, the data of the graphic 301 is deleted from the display list.

In this way, by performing control using the bounding box area and the maximum rectangular area, it is possible to eliminate unnecessary drawing processing of a figure hidden by a combination of a plurality of figures and improve the processing speed. .
Further, by performing various controls in place of simple rectangles, it is possible to greatly reduce the amount of calculation and reduce the burden on arithmetic processing and the like.

Next, the operation procedure of the page printer according to the present embodiment will be described with reference to FIGS.
7 and 8 are flowcharts showing the operation procedure of the page printer according to the present embodiment, and FIGS. 9 to 12 are explanatory diagrams for specifically explaining the operation procedure of the page printer of the present embodiment. It is.
Note that the operation procedure described here is that the page printer of this embodiment first receives the star-shaped figure 501 shown in FIG. 9A, and then displays the figure as the maximum rectangular area 502 shown in FIG. 9B. The figure which is received and then extracted as the maximum rectangular area 503 shown in FIG. 9C is extracted, and as a result, the case where the star-shaped figure 501 is completely hidden by the maximum rectangular areas 502 and 503 will be described as a typical example.

As shown in FIG. 7, first, the page printer receives print data from an information processing apparatus such as a host computer (A1), and interprets an emulation drawing command described in the print data (A2).
Next, after performing conversion processing such as position determination and size / deformation of the extracted figure, a display list is created and stored in the memory (A3).
Specifically, as shown in FIG. 10, the original figure 501 to be processed is divided and developed into a plurality of simple figures (drawing primitives) including the figures 511 to 515. That is, the path is divided in the horizontal direction with respect to each vertex (breaking point) of the path.

Here, it is determined whether or not the graphic currently being processed is a copy command for a graphic that does not include elements such as color mixing and transparency (A4). This is because the inclusion graphic deletion means, the overlapping area detection means, and the like, which are the features of the present embodiment, are targeted for filled figures.
As a result of step A4, when it is determined that the target graphic is a copy command that does not include mixed colors (A4 YES), the bounding box area of the graphic is calculated from the graphic area data (coordinate data, etc.) of the display list. (Bounding box area calculation means), in addition to the display list information, it is stored (A5).

Specifically, as shown in FIG. 11, the bounding box areas 521 to 525 are calculated for each of the figures 511 to 515 in FIG. 10, and the overlap with the figure (maximum rectangular area) drawn later is determined. set to target.
On the other hand, the determination in step A4 is performed for all the target graphics, and the rasterization process is performed as it is for the graphic (A4 NO) determined as a copy command target including transparency and color mixing (A13 in FIG. 8).

Next, the maximum rectangular area R included in the graphic of the display list is calculated by the maximum rectangular area calculating means (A6).
Here, it is determined whether or not the value of the maximum rectangular area R is 0 (zero) (A7).
As a result of step A7, when the value of the maximum rectangular area R is not 0 (zero) (A7 NO), that is, when the target figure is a rectangle or a trapezoid, the processes of steps A8 to A12 shown in FIG. 8 are performed. Starting from the graphic stored at the top n = 0 of the display list, the number of display lists is repeated (loop 2).
On the other hand, as a result of the determination in step A7 for all display lists, the graphic (A7 YES) for which the value of the maximum rectangular area R of the graphic is determined to be 0 (zero) is subjected to the rasterization process as it is (see FIG. 8 A13).

In step A8, a comparison process is performed between the maximum rectangular area R of the graphic of the display list just created and the bounding box area Bn of the graphic of the nth display list created previously.
First, it is determined whether the maximum rectangular area R and the bounding box area Bn overlap (A9). When these areas do not overlap with each other (NO in step A9), the next display list figure (n + 1th figure) is determined, and the determination in step A9 is sequentially performed for all previously created figures. I do.

As a result of step A9, if an overlap between the previously created bounding box area and the maximum rectangular area R of the currently processed figure is detected (A9 YES), then the maximum rectangular area R completely completes the bounding box area. (A10).
As a result of step A10, when the maximum rectangular area R completely includes the bounding box area (A10 YES), the graphic of the nth display list is deleted from the memory (A11).
On the other hand, as a result of step A10, when the maximum rectangular area R does not completely include the bounding box area and partially overlaps (A10 NO), the vertex of the bounding box area Bn of the nth display list The coordinate data is corrected (A12).

Specifically, the determination processing of step A9 and step A10 is performed for each of the bounding box areas 521 to 525 and the maximum rectangular area 502 shown in FIG.
As a result, the bounding box area 525 is completely included in the maximum rectangular area 502, and the graphic 515 is deleted from the display list.
Further, since the bounding box areas 521 to 524 are not completely included in the maximum rectangular area 502 and partially overlap, the vertex coordinates are corrected, and the bounding box areas are changed like 531 to 534, respectively.

  As shown in FIG. 9C, when the maximum rectangular area 503 is newly recognized, the bounding box areas 531 to 534 are all included in the maximum rectangular area 503. The data of the figures 511 to 514 are deleted from the display list.

  As described above, unnecessary graphic data is deleted from the display list by repeatedly performing the predetermined procedure shown in loop 1 and loop 2 for all the graphics in the display list. Only the substantially necessary figure above is rasterized and output as a bitmap (A13).

As described above, according to the page printer of the present embodiment, the maximum rectangular area and the bounding box area of the figure on the display list are obtained, and if these areas partially overlap, the bounding box area is changed. In addition, the presence / absence of an inclusive relationship with another figure is detected.
Then, when the bounding box area after the change is included in the maximum rectangular area of another figure, control is performed so as to delete the figure data that is the origin of the bounding box.

Thereby, not only the same effect as the first embodiment described above is exhibited, but also a complicated figure can be easily and flexibly dealt with.
In addition, since the area of the target graphic is replaced with a simple rectangular area and various controls are performed, the burden of arithmetic processing and the like can be significantly reduced.
Accordingly, the program, CPU, and the like can be made extremely simple, and a highly reliable page printer can be realized.

[Third embodiment]
Next, a page printer according to a third embodiment of the image forming apparatus of the present invention will be described with reference to FIG.
The page printer according to the present embodiment can perform so-called band processing in which a page is divided into bands (band area generation means) in consideration of memory usage and is drawn in a certain band area unit.
In band processing, it is necessary to consider the inclusion relationship and overlapping relationship of figures in the band region, but no particular problem occurs, rather, image processing can be performed more efficiently.

For example, as shown in FIG. 13A, there are three rectangles, the rectangle 601 is drawn at the top, the rectangle 602 is drawn next, and the lowermost figure is a rectangle 603.
In this case, when viewed from the whole page, the three figures only partially overlap, and there is no inclusion relationship. Therefore, as it is, the graphic data of the overlapping portion cannot be deleted by the method using the inclusion graphic deleting means.
However, as shown in FIG. 13B, when viewed in band area units, the rectangle 613 in the band (N) is included in the rectangle 611 and the rectangle 612, and thus is not regarded as a drawing target, and the display list It can be controlled to be deleted from.

In the band processing, since the display list is managed for each band, the entire rectangle 603 shown in FIG. 13A is not deleted.
As described above, the page printer according to this embodiment can be applied regardless of direct drawing processing (FULL-VRAM) or band processing on a page.

As described above, according to the page printer of this embodiment, not only the same effects as those of the first embodiment and the second embodiment are exhibited, but also the drawing processing is more efficiently performed by adopting the band processing. It can be performed.
In addition, since it can support any processing means such as direct drawing processing (FULL-VRAM) or band processing on a page, it is possible to flexibly respond to printer performance, type of output figure, quality required by the user, and the like. is there.

The image forming apparatus according to the present invention has been described with reference to the preferred embodiment. However, the image forming apparatus according to the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. It goes without saying that implementation is possible.
For example, the image forming apparatus of the present invention may be not only a page printer but also other image forming apparatuses such as a copier, a facsimile, a scanner, and the like, and a composite apparatus.

  The present invention can be suitably used in printers such as page printers, image forming apparatuses such as copiers and multifunction peripherals, and image forming systems such as network printers.

1 is an explanatory diagram for explaining the principle of a page printer according to a first embodiment of an image forming apparatus of the present invention. It is explanatory drawing for demonstrating the display list used for the page printer which concerns on 1st embodiment of the image forming apparatus of this invention. 1 is a block diagram illustrating a basic configuration of a page printer according to a first embodiment of an image forming apparatus of the present invention. FIG. 3 is an explanatory diagram for explaining a basic mechanism of the page printer according to the first embodiment of the image forming apparatus of the present invention. It is explanatory drawing for demonstrating the principle of the page printer which concerns on 2nd embodiment of the image forming apparatus of this invention. It is explanatory drawing for demonstrating the largest rectangular area used in the page printer which concerns on 2nd embodiment of the image forming apparatus of this invention. 6 is a flowchart showing the first stage of the operation procedure of the page printer according to the second embodiment of the image forming apparatus of the present invention. 6 is a flowchart illustrating a second stage of the operation procedure of the page printer according to the second embodiment of the image forming apparatus of the present invention. FIG. 10 is a first explanatory diagram for specifically explaining an operation procedure in the page printer according to the second embodiment of the image forming apparatus of the present invention. FIG. 10 is a second explanatory diagram for specifically explaining an operation procedure in the page printer according to the second embodiment of the image forming apparatus of the present invention. FIG. 10 is a third explanatory diagram for specifically explaining an operation procedure in the page printer according to the second embodiment of the image forming apparatus of the present invention. FIG. 10 is a fourth explanatory diagram for specifically explaining an operation procedure in the page printer according to the second embodiment of the image forming apparatus of the present invention. It is explanatory drawing for demonstrating a band process in the page printer which concerns on 3rd embodiment of the image forming apparatus of this invention. It is explanatory drawing which shows the deletion principle of the intermediate | middle list image in the conventional image forming apparatus.

Explanation of symbols

11 Print Data Reception Storage Unit 12 PDL Analysis Unit 13 Display List Creation Unit 14 Display List Information Correction Unit 15 Display List Deletion Unit 16 Page Rasterization Unit

Claims (4)

Data extraction means for analyzing predetermined data and extracting graphic data and area data;
A display list for sequentially storing the one or more extracted graphic data and its area data;
Included graphic deletion means for deleting the previously stored graphic data from the display list when the graphic area previously stored in the display list is included in the one graphic area stored later When,
Output means for outputting image formation data based on graphic data stored in the display list;
In the display list, an overlapping area detecting means for detecting an overlapping area between the area of the first graphic stored earlier and the area of the second graphic stored later;
An area changing means for changing the area of the first graphic to an area where the overlapping area is deleted;
The inclusion figure deleting means is:
The first graphic data is deleted from the display list when the area of the first graphic changed by the area changing means is included in a graphic area other than the second graphic stored later. An image forming apparatus. Maximum rectangular area calculating means for calculating a maximum rectangular area of the figure based on the area data;
A bounding box area calculating means for calculating a bounding box area of the figure based on the area data,
The overlapping area detecting means detects an overlapping area between the bounding box area of the first graphic stored earlier and the maximum rectangular area of the second graphic stored later in the display list,
The area changing means changes the bounding box area of the first graphic to an area where the overlapping area is deleted,
The inclusion graphic deletion means is configured such that when the bounding box area of the first graphic changed by the area change means is included in the maximum rectangular area of the graphic other than the second graphic stored later, the first graphic The image forming apparatus according to claim 1, wherein the graphic data is deleted from the display list.   The image forming apparatus according to claim 1, wherein the area data includes at least predetermined coordinate data. A band area generating means for generating a plurality of band areas by dividing a page frame as an output unit based on a certain standard,
The data extraction means analyzes predetermined data, extracts graphic data and its area data for each band area,
4. The image forming apparatus according to claim 1, wherein the display list sequentially stores one or more extracted graphic data and its area data for each band area.

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