JPH10149148A - Screen processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To guarantee the order of drawing without making a means for drawing characters wait even when the characters overlap. SOLUTION: This processor has an instruction buffer 201 which stores character drawing instructions indicating the drawing of characters as many as specific characters, an instruction detection part 203 which detects whether or not the characters to be drawn with the stored instructions overlap, an overlap part drawing instruction generating means 204 which generates an overlap part drawing instruction indicating the drawing of nonoverlap parts of the characters, and an overlap part drawing instruction generation part 205 which generates an overlap part drawing instruction indicating the drawing of the overlap part and the order of the drawing when the overlap is detected. Then the characters are expanded according to the respective instructions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
In an image processing apparatus that inputs code image data described in (page description language), interprets the image data, and develops the image data into bitmap image data, a plurality of means for forming characters and the like are simultaneously operated in parallel. The present invention relates to an image processing apparatus capable of drawing characters in a correct order without making these units wait.

[0002]

2. Description of the Related Art When code image data described in PDL is used, an image in which image data such as a photograph, a diagram, a table, characters, and the like (which are collectively referred to simply as an object) are mixed. It is possible to output to a common output device between terminals of different models, or to output data of the same format to different output devices. For this reason, PDL has recently been widely used when outputting images. As is well known, when an image represented by such code image data is printed by a page printer, the contents of the code image data are interpreted, developed into bitmap data required by the printer, and temporarily stored in a frame buffer. After storing, it is necessary to supply in synchronization with the output operation (main scanning operation and sub-scanning operation) of the printer.

In recent years, printer engines that form images in accordance with bitmap data have recently been developed.
For example, some color page printers that can print at about 35 to 40 pages per minute are appearing. However, at present, it cannot be said that the printing capability of such a page printer is fully utilized. The biggest cause is that the processing speed for expanding the code image data described in PDL into bitmap data is too slow to follow the output operation of the printer. One of the reasons why the processing speed for developing bitmap data is low is that the ability to develop characters is low. In the field of DTP (Desktop Publishing), vector font data (sometimes called an outline font or a scalable font) is generally used for characters. This is because, if vector font data is used, characters can be drawn with an arbitrary size (number of points) and with an arbitrary resolution, which is optimal in the field of DTP where high image quality is required. However, when vector font data is actually used, it is necessary to develop the vector font data into bitmap data indicated by a desired number of points and resolution. Since the load of such expansion processing is large, the ability to expand characters is inevitably reduced.

One solution to this problem is to use a font cache. That is, once a certain character is expanded into bitmap data, the expanded bitmap data is output and cached in a cache memory. If an output request is issued for the same character, the bitmap data is cached. It uses bitmap data.
This makes it possible to omit the second and subsequent expansion processes for the same character, thereby increasing the speed of character output. However, with the font cache method,
The effect can be expected as the capacity of the cache memory is larger, but there is a disadvantage that it is costly to secure the capacity. In addition, since the effect cannot be expected unless caching is performed, there is also a basic problem that the tendency of lowering the character output appears immediately after the start of printing regardless of the size of the capacity.

Therefore, it is conceivable to provide a plurality of expanding means for expanding the bitmap data. That is, these are simultaneously operated in parallel so as to perform expansion processing on separate objects, thereby increasing the overall speed. However, when providing a plurality of developing means, it is necessary to pay attention to the order in which objects such as characters are drawn. This will be described with reference to FIG. Now, as shown in FIG. 9A, the correct drawing order is “L”, “E”, and “V”, and each of these characters is processed by different developing means in parallel. Think about. The time required for character expansion processing generally depends on the complexity of the character, and if a font cache is used, it greatly differs depending on whether or not there is a hit. For this reason, the timing at which each developing means finishes developing each character is not uniformly determined due to differences in various conditions. Therefore, even if each developing means starts the developing process for one character of "L", "E", and "V" in that order, the timing of completion of the developing is "V", "E", "L". It is quite possible that the opposite is true. In this case, as shown in FIG. 7B, the obtained image is unintended.

As a technique for considering the drawing order, there is a technique described in, for example, Japanese Patent Application Laid-Open No. 4-327966. This technique will be briefly described with reference to FIG. When receiving the command to instruct drawing, the main processing unit 11 determines whether or not the command is a character generation command to instruct drawing of a character. An object is formed and stored in the frame memory 20 via the access right management unit 21. Here, the access right management unit 21
When an object such as a diagram is stored in the frame memory 20 from the main processing unit 11, the access rejection setting is performed, and the access to the frame memory 20 is prohibited.
In addition, if the received instruction for drawing is a character generation command, the main processing unit 11 supplies the instruction to the font control unit 14. When receiving the character generation command, the font control unit 14 obtains the bitmap data of the character according to the command from the dot character generation unit 16 or the font cache memory 17, and cancels the access rejection of the access right management unit 21. , In the frame memory 20. As a result, the characters and other diagrams and the like are stored in the frame memory 20 in the correct order. Also, the above publication discloses a dot character generation unit 1.
A technique for performing character expansion in parallel using a plurality of characters 6 is also described.

[0007]

However, according to the technique described in the above-mentioned publication, for example, when drawing is performed in the same area in the order of a diagram and a character, the main processing section 11 speeds up the process of forming the diagram. Even so, there is a drawback in that the dot character generator 16 must obtain the bitmap data of the character, store it in the frame memory 20, and wait until the access rejection is added. Therefore, the main processing unit 11
Is configured to execute other processing during standby. Also, in the above publication, even when the dot character generation units develop characters in parallel, the order of transfer to the frame memory 20 is managed in a unified manner. For this reason,
A problem arises in that one dot character generation unit must wait for the progress of another dot character generation unit. In other words, the technique described in the above publication intends to ensure that the objects are stored in the frame memory 20 even if the objects overlap, so that drawing is performed correctly. In addition, there is a disadvantage that the expansion processing becomes inefficient.

The present invention has been made in view of the above circumstances, and has as its object to provide, for example, a plurality of drawing means for drawing an object, especially a character, which independently draws. An object of the present invention is to provide an image processing apparatus capable of drawing an overlapped character in a state in which the order is guaranteed without having to wait for each drawing unit.

[0009]

In order to solve the above-mentioned problems, according to the present invention, at least two or more drawing commands instructing the drawing of characters are input, and characters drawn by the commands are input. Detecting means for detecting whether or not they are overlapped; first command generating means for generating a first command for drawing a non-overlapping part from a drawing command for the character when the overlap is detected; A second command generation unit configured to generate, from the drawing command related to the character, a second command that specifies the drawing of the overlapping portion and the drawing order, when the overlapping is detected; And a drawing means for performing drawing.

According to the present invention, when characters overlap, the drawing command for the character includes a first command for instructing the drawing of a non-overlapping portion, and the order of drawing and drawing of the overlapping portion. , And a drawing is actually performed by these instructions. Therefore, even if there are a plurality of drawing means and these are configured to independently draw characters in accordance with the commands, a state in which the order of the overlapping characters is guaranteed without waiting for each drawing means. Can be drawn.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

<1: Configuration of Embodiment> FIG. 1 is a block diagram showing a configuration of an image processing apparatus according to the present embodiment. In the figure, a CPU 101 controls each unit via a bus B. The ROM 102 stores a boot program 103, a document development program 104, a print control program 105, and the like. Here, the boot program 103 is for initializing the entire apparatus immediately after power-on or immediately after resetting, and the expansion program 104 is for expanding code image data described in PDL into bitmap data. Print control program 105
Is for controlling activation of the printer engine 109 and supply of expanded bitmap data when printing is performed.

A frame buffer 107 and a work memory 108 are allocated to one area of the RAM 106. The former frame buffer 107 is used as an area for temporarily storing one page of image data developed into bitmap data before being supplied to the printer engine 109, and the latter is a work memory 108.
Are used as a temporary (temporary work) area at the time of expansion processing and an area for temporarily storing vector font data 114 (described later) at the time of character expansion. The printer engine 109 forms and outputs an image on a sheet in accordance with bitmap data supplied via a printer I / F (interface) 110.

On the other hand, a host W / S (work station) 111 is connected to the bus B via a host I / F 112, and creates and outputs image data including characters. In the present embodiment, the host W / S1
The image data created by 11 is code image data described in PDL. Also, the host W / S11
1 is actually connected to the bus B via a network, but its protocol is the host I / F 112
Therefore, the CPU 101 does not need to be aware of the protocol. Therefore, in the figure, the network is omitted, and the host W / S 111
/ F112 connected to the bus B.

The hard disk 113 mainly stores the vector font data 114 for each font.
If there is enough space, document data and bitmap image data may be stored. Here, the vector font data 114 stores character outlines as vector data for each character in accordance with character codes defined in ASCII, JIS first level, JIS second level, and the like. A plurality of fonts are stored for each font, such as morning and gothic.

The rasterizers 115a to 115c perform expansion processing on characters in accordance with a character drawing command, a later-described overlapping part drawing command or a non-overlapping part drawing command, and operate in parallel under the control of the rasterizer controller 116. It is. Here, the character drawing command has a format as shown in FIG. 3A, and for one character, a font I indicating a font of a character to be drawn.
D, a character code indicating the code of the character, a conversion matrix that determines the shape of the bounding box, coordinates (X, Y) indicating the position to be drawn for the character by the coordinates of the upper left corner of the bounding box, and the like. . Of these, the bounding box refers to a character drawing area, as shown in FIG. 14, and has a parallelogram shape when italic (italic). In the case of a proportional font, the width differs for each character.
Although not shown, the character drawing command also includes character attribute information, for example, a color designation command for defining a drawing color. Then, a character drawing instruction composed of these data is:
CPU 101 continuously supplies a predetermined number of characters. At this time, the order in which the character drawing commands are supplied indicates the order in which characters should be drawn. The meaning of the predetermined number of characters will be described later. When the rasterizers 115a to 115c receive the color designation command, the rasterizers 115a to 115c store information on the color designated by the command in the shared memory 119.

The description returns to FIG. When one page of bitmap data is stored in the frame buffer 107, the DMAC (direct memory access controller) 117 reads the data and transfers it to the printer engine 109 in accordance with an instruction from the CPU 101. The shared memory 119 includes a rasterizer 115
These memories are shared and used by a to 115c and cannot be referenced from the CPU 101. A part of the shared memory 119 is allocated as a font cache area. Overlap processing unit 120
Preprocesses a character drawing command supplied to the rasterize 115a to 115c, and separates the character drawing command into an overlapped portion having overlapping characters and a non-overlapping portion having no overlap, and decomposes and reproduces the character drawing command as necessary. Is what it does. Details will be described below.

<1-1: Overlap Processing Unit> Overlap Processing Unit 1
The detailed configuration of 20 will be described with reference to FIG. In this figure, a command buffer 201 is a buffer for receiving a character drawing command from the CPU 101, and receives a character drawing command in units of a predetermined number of characters.
The overlap command detection unit 202 specifies a character drawing command stored in the command buffer 201, detects whether or not an overlapping occurs in a bounding box of a character drawn by the command. Prints character sets and their overlapping ranges. Instruction fetch unit 2
Numeral 03 fetches character drawing commands one by one from the command buffer 201 and supplies a character drawing command of a non-overlapping character to the rasterizer control unit 116 by referring to the detection result by the overlapping command detecting unit 202, The drawing command is supplied to the non-overlapping part drawing command generation unit 204 and the overlapping part drawing command generation unit 205 together with the overlapping range detected by the overlapping command detection unit 202.

A non-overlapping partial drawing command generation unit 204 generates a non-overlapping partial drawing command from the overlapping range and a character drawing command supplied from the command fetching unit 203, which is a character drawing command of a character corresponding to the overlapping range. Then, it is supplied to the rasterizer control unit 116. Here, the non-overlapping partial drawing command is a command for instructing drawing of only a non-overlapping region among characters having overlapping bounding boxes. Specifically, a format as shown in FIG. And has a non-display range designation 302 and a non-overlapping character designation 303. Here, the non-display range designation 302 designates an overlapping range of a bounding box, and the overlapping range is a rectangular area having a straight line connecting two sets of coordinates (X, Y) as a diagonal line. The non-overlapping character designation 303 designates a character with which the bounding box overlaps, and a font I indicating the font of the character is designated.
D, a character code indicating the code of the character, a conversion matrix indicating the shape of the bounding box, and (X, Y) indicating the position where the character should be drawn by the coordinates of the upper left corner of the bounding box. . By such a non-overlapping part drawing command, information necessary for drawing only an area where no overlapping occurs among characters whose bounding boxes overlap is provided.

On the other hand, the overlapping part drawing command generation unit 205
An overlapping range detected by the overlapping instruction detecting unit 202;
An overlapping part drawing command is generated from the character drawing command of the character corresponding to the overlapping range and the character drawing command supplied from the command fetch unit 203, and the rasterizer control unit 116
Is to be supplied to Here, the overlapping part drawing command is a command for instructing drawing of only the area where the overlapping occurs in the characters where the bounding boxes overlap, and has a format as shown in FIG. , A display range specification 304 and a duplicate character specification 305 to 305.
Here, the display range designation 304 designates an overlapping range of the bounding box, and the overlapping range is a rectangular area having a straight line connecting two sets of coordinates (X, Y) as a diagonal line. The display range designation 304 further describes the number of characters that overlap in the overlapping range. The duplicate character designation 305 designates a character whose bounding box overlaps, and is provided in accordance with the number of characters overlapping in the overlapping range and in the order in which the characters are to be drawn. As with the content of the non-overlapping character specification, the contents include a font ID indicating the font of the character, a character code indicating the code of the character, a conversion matrix indicating the shape of the bounding box, and a position where the character is to be drawn. , (X, Y) indicated by the coordinates of the upper left corner of the bounding box. By such an overlapping part drawing instruction, information necessary for drawing only an area where the overlapping occurs among the characters overlapping the bounding box is provided.

When a command related to character drawing such as the overlapping part drawing command, the non-overlapping part drawing command or the character drawing command is received, the rasterizer control unit 116 sends the command to one of the rasterizers 115a to 115c.
Appropriate distribution is performed according to the processing status. Then, upon receiving a command related to character drawing, the rasterizers 115a to 115a
115c stores the bitmap data according to the instruction in the frame buffer 107 by performing the following processing.

That is, the rasterizers 115a-115
c, upon receiving the command related to the character drawing, first determines whether or not the expansion result of the command is cached, and if not, secondly, converts the vector font data of the character related to the command into Coordinate conversion, thirdly, a correction process, and fourthly, the vector font data is developed into a character outline, and the developed result is transferred to a cache area allocated to the shared memory 119 and stored therein. Fifth, the area surrounded by the outline is painted in the color designated by the color designation command, and bitmap data of the character according to the character drawing command is generated.
This bitmap data is transferred to the frame buffer 107
Then, the data is transferred to the area corresponding to the coordinates specified by the character drawing command. On the other hand, the rasterizers 115a to 115c
When an instruction related to character drawing is received, if the expansion result of the instruction is cached, the expansion result is read and used. In this way, the frame buffer 107 stores the bitmap data of the character developed according to the instruction related to the character drawing. Therefore, the rasterizer 11 in the present embodiment
5a to 115c do not consider the progress of other rasterizers. If the transfer area is specified,
The rasterizers 115a to 115c transfer only the area to the frame buffer 107.

<2: Operation> Next, the operation of the image processing apparatus according to the above-described embodiment will be described. In addition, PD
L generally handles not only characters, but also diagrams, images, and the like. However, in the present embodiment, character overlap will be described as an example. Therefore, for convenience of description, code image data described in PDL will be described below. , A document consisting of only characters.

<2-1: Operation in CPU> CPU1
FIG. 4 is a flowchart showing the operation of the operation No. 01. First, when the image processing apparatus is turned on or reset, the CPU 101 reads the boot program 103 from the ROM 102 in step Sa1, executes the program, and performs initialization. This initialization corresponds to, for example, a process of allocating an area of the frame buffer 107 or the work memory 108 to the RAM 106. Next, the CPU 101 determines in step Sa
At 2, the process waits until code image data from the host W / S 111 is received. Upon receiving the code image data, the CPU 101 stores the data in an input buffer (not shown) allocated to the RAM 106 in step Sa3. When all the code image data for one job is stored, the CPU 101
Performs the following processing. In order to speed up the entire process, the following process may be executed when code image data is input by a predetermined amount.

When all or a predetermined amount of code image data for one job is stored, the CPU 1
In step Sa4, 01 is set as the target of the expansion processing on the first page. Since the code image data described in the PDL generally indicates an image of one or a plurality of pages, it is set so that the expansion processing is performed for the first page for the time being. Next, CPU
In step Sa5, a character rendering command for a page set as a processing target is output in the rendering order, and an instruction is given to perform a rendering process on the page. The details will be described later.

Then, in step Sa6, the CPU 101 waits until all bitmap data relating to the page to be processed is stored in the frame buffer 107. When the storage in the frame buffer 107 is completed, the CPU 101 activates the printer engine 109 in step Sa7 and
It instructs the MAC 117 to transfer the bitmap data stored in the frame buffer 107 to the printer engine 109. As a result, the page to be processed is actually printed.

Next, in step Sa8, the CPU 101 determines whether or not the expansion processing has been completed for all the pages. If not completed, the CPU 101 shifts the processing procedure to step Sa9 and sets the target of the expansion processing to the next. After setting the page, the procedure returns to step Sa5 again. Thereafter, the processing procedure circulates through steps Sa5 to Sa9, and the expansion processing is completed for all pages.
On the other hand, if it is determined in step Sa8 that the processing has been completed for all pages, the CPU 101
Returns the processing procedure to step Sa2 again, waits until code image data relating to a new job is received, and executes the processing of steps Sa3 to Sa9 to execute development / printing each time the code image data is received. It has become.

<2-2: Operation in Overlapping Processing Unit> C
When the PU 101 outputs the character drawing command for the set page in the drawing order in step Sa5 described above, the overlap processing unit 120 executes the operation shown in FIG. 5, pre-processes the character drawing command, Output to the rasterizer control unit 116.

First, in step Sb1, the command buffer 201 stores a character drawing command for the page for a predetermined number of characters. Here, the predetermined number of characters means
For example, the number of characters may be the number of all characters in the page to be processed, the number of characters of one to several lines, or the punctuation marks "." It may be the number of characters to be sandwiched. That is,
Here, the predetermined number of characters is a property that should be determined in consideration of a certain character, when attention is paid to the character, and to what extent the character and the subsequent characters overlap.

Next, in step Sb2, the instruction fetch unit 203 detects the number of character drawing instructions stored in the instruction buffer 201 and sets this number to n.
In step Sb3, “1” is set to m, and the values of n and m are notified to the overlap instruction detecting unit 202.
Then, in step Sb4, the overlap command detection unit 202 calculates a bounding box (BB) for the m-th character drawing command, and then in step Sb5, among the character drawing commands other than the m-th character drawing command, , Which are different from the attribute information, for example, anounding box according to a command to instruct drawing in a color different from the m-th character. Then, the overlapping instruction detecting unit 2
In step Sb6, in step Sb6, it is determined whether or not the bounding box of the character according to the m-th character drawing command overlaps the bounding box obtained in the immediately preceding step, and the result of the determination is notified to the instruction fetch unit 203. Therefore, even if the bounding box of the character drawing instruction instructing the same color drawing as the character related to the m-th character drawing command is actually the same as the character bounding box of the character related to the m-th character drawing command, In step Sb6, it is not determined that they overlap. This is because if the same color characters overlap, it is not necessary to guarantee the drawing order (see FIG. 12C). Here, as an example in which the attribute information of the character is different, a color attribute that has a large effect on the appearance in color printing, that is, a color to be drawn is described, but the present invention is not limited to this. In addition, as the attribute information of the character, a halftone pattern (such as a shade), a color pattern, a gradation, a pasted image, and the like can be considered. Here, as the color pattern, information that defines the components of the character, such as vertical / horizontal stripes, a specific pattern (such as a character pattern), and small characters when a large character is composed of small characters, can be considered. . That is, the attribute information of a character in the present application refers to all information that is affected by the order of superposition of characters.

If it is determined by the notification from the overlapping instruction detecting unit 202 that there is no overlap, the instruction fetching unit 2
In step Sa7, the m-th character drawing command is extracted from the command buffer 201 and output to the rasterizer control unit 116 as it is in step Sa7. On the other hand, if they overlap,
In step Sb8, the overlap command detection unit 202 also notifies the command fetch unit 203 of a character drawing command related to a character overlapping the overlap range. Then, the instruction fetch unit 203 fetches from the instruction buffer 201 the character drawing instruction having the overlapping bounding box together with the m-th character drawing instruction, and extracts the character drawing instruction and the overlapping range thereof into the non-overlapping partial drawing instruction generation instruction. This is supplied to the section 204 and the overlapping part drawing command generation section 205.

Upon receiving these commands, first, in step Sb9, the non-overlapping part drawing command generation unit 204 generates a non-overlapping part drawing command (see FIG. 3B) and outputs it to the rasterizer control unit 116. . Next, step S
In b10, the overlapping part drawing command generation unit 205 sets m
An overlapping part drawing command is generated for the characters following the first character and output to the rasterizer control unit 116. here,
"About the character after the m-th character" means that, for an overlap portion between the m-th character and the character before the m-th character,
This is because the character has already been generated when the character before the first character has been processed, and this means that the same processing is repeated again to prevent a reduction in speed.

Upon receiving the character drawing command, the non-overlapping part drawing command or the overlapping part drawing command, the rasterizer control unit 116 causes the rasterizers 115a to 115c to
To one of the above, depending on the processing situation,
The character drawing according to the instruction is performed. This allows
The character according to the command is drawn in the frame buffer 107. Next, in step Sb11, m
It is determined whether or not n is equal. If not, the value of m is incremented by “1” in step Sb12, and the value of m is notified to the overlap instruction detecting unit 202. As a result, the overlap command detection unit 202 similarly performs overlap detection for a character drawing command for the next character stored in the command buffer 201. On the other hand, m
If n and n are equal, it is determined in step Sb12 whether or not all the character drawing commands for the processing target page have been preprocessed. If not, the processing procedure returns to step Sb1 again, and the next predetermined number of characters The same processing is continuously executed for the character drawing command. Also, if the pre-processing has been completed for all the character drawing commands,
When the development processing for the page ends, and the processing target has shifted to the next page (step Sa9), the overlap detection is performed again.

<3: Specific Operation> In the image processing apparatus that performs the above-described operations, the drawing operation in the present embodiment will be described below by taking a specific example of a character drawing command. Now, assume that the character drawing command stored in the command buffer 201 is as shown in FIG. 6A, and the predetermined number of characters is “3”. However, the character colors drawn by these character drawing commands are different from each other. In detail, by character drawing instructions 601 to 603,
The 1st, fonts and double-byte characters "L" is a character code to a "Gothic" is "234C" in the transformation matrix A coordinate value of the upper left corner is (X _1, Y ₁₎ is Φ draw at certain bounding box, secondly, fonts and double-byte characters "E" is a character code to a "Gothic" is "2345", the coordinate values of the upper left corner (X _2, Y ₂₎
, And the transformation matrix is drawn in a bounding box with Φ. Third, the font is “Gothic”.
Double-byte characters "V" was in the character code "2356" is, a coordinate value of the upper left corner is (X _1, Y _1), so that the transformation matrix is rendered at the bounding box is Φ Suppose you are instructed. The bounding boxes of the characters drawn by the character drawing commands 601 to 603 are denoted by reference numerals 601B to 601B shown in FIG.
It is assumed that the positional relationship is 603B. That is, FIG.
As shown in FIG. 2A, this is a case where characters are to be drawn in the order of “L”, “E”, and “V”.

Such character drawing commands 601 to 603
Are sequentially output by the CPU 101 (step Sa5), the overlap processing unit 120 stores these drawing commands in the command buffer 201 (step Sb1), and outputs "3" indicating the number of these drawing commands. Is n
(Step Sb2), “1” is set to m (step Sb3), and the first processing target is the character drawing instruction 601. Next, the bounding box 601B of the character according to the character drawing command 601 is calculated (step Sb4), and the other character drawing commands 60 are calculated.
The bounding box 60 for the character that spans 2,603
2B and 603B are sequentially calculated and obtained (step Sb5). Here, the bounding box 601B
6B, as shown in FIG. 6B, overlaps with the bounding box 602B in a rectangular area having a straight line connecting the coordinates (a, b) to the coordinates (c, d) as a diagonal line. Therefore, the character drawing command 601 is supplied to the non-overlapping part command generator 204 and the overlapping part command generator 205 together with the character drawing command 602 overlapping with the character drawing command 602 (step Sb8).

Therefore, this time (m = 1), step Sb
The non-overlapping part instruction generated at 9 is as shown in FIG. That is, among the areas to be drawn by the character drawing command 601, the coordinates (a, b) to the coordinates (c, d)
Are not displayed (not drawn) except for a rectangular area whose diagonal is a straight line connecting. Therefore, the image drawn by the non-overlapping part command is the one excluding the overlapping range as shown in FIG.

On the other hand, the duplicate part instruction generated in step Sb10 is as shown in FIG. In other words, of all the regions to be drawn by the character drawing commands 601 and 602, only a rectangular region having a straight line connecting the coordinates (a, b) to the coordinates (c, d) as a diagonal is displayed (drawn). Then, the drawing order is set to the overlapping character designations 801 and 80.
The order is 2. Therefore, the image drawn by the overlapping part command is only the overlapping range as shown in FIG.
"E".

In the next step Sb11, since m is still "1" and not n (= 3), step Sb11 is executed.
In b12, m is set to “2”. Therefore, next, the bounding box 602B of the character according to the character drawing instruction 602 is calculated (step Sb4), and the bounding boxes 601B and 603B of the characters according to the other character drawing instructions 601 and 603 are sequentially calculated (step Sb4). Step Sb5). Here, the bounding box 602B is, as shown in FIG. 6B, in a rectangular area having a diagonal line connecting the coordinates (a, b) to the coordinates (c, d) with the bounding box 601B, and The bounding box 603B overlaps with each other in a rectangular area having a straight line connecting the coordinates (e, f) to the coordinates (g, h) as a diagonal line. Therefore, the character drawing command 602 includes the character drawing commands 601 and 603 overlapping with the character drawing command 602, the overlapping range thereof, and the non-overlapping partial command generator 204 and the overlapping part command generator 20 respectively.
5 (step Sb8).

Therefore, this time (m = 2), step Sb
The non-overlapping partial instruction generated at 9 is as shown in FIG. That is, among the areas to be drawn by the character drawing command 602, the coordinates (a, b) to the coordinates (c, d)
And a rectangular area having a diagonal line connecting the coordinates (e, f) to (g, h) is a non-display area. Therefore, the image drawn by the non-overlapping part command is the one excluding the overlapping range as shown in FIG.

On the other hand, the duplicate part instruction generated in step Sb10 is as shown in FIG.
In other words, of the entire area to be drawn by the character drawing commands 602 and 603, only a rectangular area having a straight line connecting the coordinates (e, f) to the coordinates (g, h) as a diagonal is displayed. The order of drawing is specified by duplicate character designation 1001, 1002
It is what it was. Here, the reason that the character drawing instruction 601 is not taken into consideration is that the instruction 601 is not the second and subsequent ones but the first, and the overlapping part with this character is already m
This is because the value has already been obtained in step Sb10 when = 1. Therefore, the image drawn by this overlapping portion command is only the overlapping range, and the drawing order is “E” and “V”, as shown in FIG.

In the next step Sb11, m is still "2" and not n (= 3).
In b12, m is set to “3”. Therefore, next, the bounding box 603B of the character according to the character drawing instruction 603 is calculated (step Sb4), and the bounding boxes 601B and 602B of the characters according to the other character drawing instructions 601 and 602 are sequentially calculated (step Sb4). Step Sb5). Here, as shown in FIG. 6B, the bounding box 603B and the coordinates (e, f) to (g,
h) overlap in a rectangular area having a straight line connecting diagonal lines connecting the straight lines connecting h). Therefore, the character drawing command 603 is supplied to the non-overlapping part command generator 204 and the overlapping part command generator 205 together with the character drawing command 602 overlapping with the character drawing command 603 (step Sb8).

Therefore, this time (m = 3), step Sb
The non-overlapping partial instruction generated at 9 is as shown in FIG. That is, among the areas to be drawn by the character drawing command 603, the coordinates (e, f) to the coordinates (g,
A rectangular area having a straight line connecting h) as a diagonal line is not displayed. Therefore, the image drawn by the non-overlapping part command is the one excluding the overlapping range as shown in FIG. On the other hand, this time (m = 3), no overlapping part instruction is generated in step Sb10. The reason is that the character drawing command 603 is the last third character, and there is no character drawing command thereafter. Then, in the next step Sb11, since m is "3" and equal to n, it is determined in step Sb13 whether or not there is a character drawing command for the next predetermined number of characters. Is performed for all the character drawing commands for the target page.

As described above, the character drawing commands 601 to 603
Are regenerated into non-overlapping part drawing commands 700, 900, 1100 and overlapping part drawing commands 800, 1000 by the preprocessing of the overlap processing unit 120, and are respectively transmitted to the rasterizers 115a to 115a through the rasterizer control unit 116.
15c. Here, regardless of the order in which the rasterizers 115a to 115c draw the regenerated commands in any order, the obtained image is drawn in the correct order shown in FIG. Therefore,
According to the present embodiment, even if there are a plurality of rasterizers, characters can be drawn in a correct order without stopping the operation.

It should be noted that in the present embodiment, a character having an overlap is rendered separately into a non-overlapping part drawing instruction and an overlapping part drawing instruction, so that it takes time to develop the character. It is too early. The reason for this is that if the result of the first expansion is cached, the font cache is hit for the second processing, and there is no need to perform the expansion processing again. Therefore, the time required for the processing of developing the overlapping characters is substantially the same as the time required for the processing of developing the non-overlapping characters. Similarly, in the present embodiment, the bounding box is calculated many times for the same character (steps Sb4 and Sb5). The first calculation is performed, the result is cached, and the second and subsequent times are calculated. If the cache result is used, it is not necessary to calculate again. Therefore, in the present embodiment, no matter how many characters overlap, the time required for the expansion processing is almost the same as in the case where there is no overlap.

Even if there are overlapping characters, if the attribute information of the characters is the same (in the embodiment, if the characters are drawn in the same color), the character drawing command for those characters is Since the non-overlapping part drawing command and the overlapping part drawing command are not regenerated, the processing speed is also improved in this regard. In the present embodiment,
Although the object is only characters, it is needless to say that the present invention is not limited to this and can be applied to the development of a diagram or the like.

[0046]

As described above, according to the present invention, even if there are a plurality of drawing means for drawing a character in accordance with an instruction and these are configured to draw independently, a character having an overlapping character is displayed. Can be drawn in a state in which the order is guaranteed without making each drawing unit stand by.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an overlap processing unit according to the first embodiment.

3A is a diagram illustrating a configuration of a character rendering command, FIG. 3B is a diagram illustrating a configuration of a non-overlapping portion rendering command, and FIG. 3C is a diagram illustrating a configuration of an overlapping portion rendering command; is there.

FIG. 4 is a flowchart illustrating an operation of a CPU according to the embodiment.

FIG. 5 is a flowchart showing an operation of the overlap processing unit in the embodiment.

FIG. 6A is a diagram showing a configuration of a character drawing command for describing a specific operation in the embodiment;
(B) is a diagram showing a positional relationship of a bounding box of a character drawn by the command shown in (a).

FIG. 7A shows the instruction shown in FIG.
7A and 7B are diagrams illustrating a configuration of a non-overlapping part drawing command when processing is performed in FIG. 6B, and FIG. 7B is a diagram illustrating an image of a character drawn by the command illustrated in FIG.

FIG. 8A shows the instruction shown in FIG.
7A and 7B are diagrams illustrating a configuration of an overlapped part drawing command when processing is performed in FIG. 5B, and FIG. 7B is a diagram illustrating an image of a character drawn by the command illustrated in FIG.

FIG. 9 (a) shows the instruction shown in FIG. 6 (a) with m = 2
7A and 7B are diagrams illustrating a configuration of a non-overlapping part drawing command when processing is performed in FIG. 6B, and FIG. 7B is a diagram illustrating an image of a character drawn by the command illustrated in FIG.

FIG. 10 (a) shows the instruction shown in FIG.
2A and 2B are diagrams illustrating a configuration of an overlapping part drawing command when processing is performed in step S2, and FIG. 2B is a diagram illustrating an image of a character drawn by the command illustrated in FIG.

FIG. 11 (a) shows the instruction shown in FIG.
3A and 3B are diagrams illustrating a configuration of a non-overlapping part drawing command when processing is performed in step S3, and FIG. 4B is a diagram illustrating an image of a character drawn by the command illustrated in FIG.

12A is a diagram showing an image drawn in a correct order, FIG. 12B is a diagram showing an image drawn in an incorrect order, and FIG. 12C is a diagram showing an image drawn in the same color. is there.

FIG. 13 is a block diagram illustrating a configuration of a conventional image processing apparatus.

FIG. 14 is a diagram for explaining the concept of a bounding box.

[Explanation of symbols]

115a to 115c: rasterizer (rendering unit), 116: rasterizer controller (rendering controller), 202: overlapping instruction detector (detector), 203: instruction fetch unit (transfer unit), 204: non- Duplicate part instruction generation means (first instruction generation means) 205... Duplication part instruction generation means (second instruction generation means)

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Claims (4)

[Claims] 1. A detecting means for inputting at least two or more drawing commands instructing drawing of a character and detecting whether or not characters drawn by the command are overlapped. First command generation means for generating a first command for drawing a non-overlapping portion from a drawing command related to a character; and drawing an overlap portion from the drawing command related to the character when the overlap is detected. An image processing apparatus, comprising: a second command generation unit for generating a second command for designating a drawing order and a drawing order; and a drawing unit for actually performing drawing based on each command. 2. An image processing apparatus according to claim 1, wherein said drawing means comprises a plurality of drawing means, and a drawing control means for assigning a drawing command to each of said plurality of drawing means one by one. 3. The image processing apparatus according to claim 1, further comprising a transfer unit configured to directly transfer a drawing command for the character to the drawing unit when the detection unit detects that there is no overlap. 4. The image processing apparatus according to claim 1, wherein the detection unit performs the detection only for a drawing command having different character attribute information.