JP2002127512A - Imaging apparatus and imaging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an imaging apparatus in which generation of a memory overflow error is deterred at a low cost. SOLUTION: The imaging apparatus comprises means 202 for calculating a work memory capacity and an intermediate image memory capacity required for forming an intermediate image for each command of image information, means 206 for acquiring an available memory capacity, means 203 for making a decision whether the memory capacity is deficient or not from the necessary memory calculating means 202 and the empty memory capacity acquiring means 206, means 204 for reconstituting the command of image information based on the decision results from the overflow decision means 203, and means 207 for forming a bit map based intermediate image from the image information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which receives data as image information from a transmission terminal such as a personal computer and converts the image information into a raster image to perform a hard copy. The present invention relates to a technique effective when applied to a case where commands included in information are reconfigured in accordance with a memory environment of an image forming apparatus for each command processing.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus, for example, a printer such as a color laser beam printer and a host computer are connected by using a standard interface such as Ethernet (registered trademark). Here,
The application on the host computer passes the image information created by the user to the printer driver, and the printer driver transmits the image information (Pri) which can be interpreted by the printer.
nter Description Language)
(Hereinafter referred to as “PDL”) and the created image information is transmitted to the printer via a standard interface. When the printer receives the image information, it interprets the image information, develops it into a raster image, and outputs it to the printer engine. The printer engine is configured to output a received raster image as a hard copy.

In recent years, printers have been required to have high image quality, and the data processing resolution is 600 dpi.
The above is the standard. And the printing resolution is 600
When the dpi, the gradation is binary, the color is CMYK, and the print size is A4, the capacity is 16 MB, which is a major factor in cost increase.

The problem is that one page is divided into a plurality of bands without having a bit map memory for one page, a memory for several bands is provided, and a bit is stored in a band memory (hereinafter referred to as a "band buffer"). In some cases, the map is sequentially developed and printed.

In a printer having a PDL, usually, an intermediate language or an intermediate image (DisplayList)
It is called "DL". ) Is converted from the PDL into a form called ")", and the bitmap is developed from the DL to the band buffer using a hardware rasterizer, so that the speed of the development to the band buffer is increased, and the output is made in time for the engine output.

[0006]

However, in the above-described conventional color laser beam printer, it is necessary to create a DL in order to speed up the development from the PDL to the bitmap data, and a memory capacity for creating the DL is required. When the size became large, the memory became insufficient and a memory overflow error occurred.

It is an object of the present invention to provide an image forming apparatus capable of suppressing the occurrence of a memory overflow error at low cost.

[0008]

In order to solve this problem, an image forming apparatus according to the present invention is an image forming apparatus that interprets image information created by an information processing apparatus, develops the information into bitmap data, and outputs the bitmap data. A required memory calculating unit for calculating a work memory amount and an intermediate image memory amount necessary for creating an intermediate image for each command of image information; a free memory amount obtaining unit for obtaining an available memory amount; and a required memory calculating unit Overflow determining means for determining whether there is a memory shortage from the free memory amount acquiring means, a command reconstructing means for reconstructing a command of image information based on a result of the judgment by the overflow determining means, and creating an intermediate image from the image information And an intermediate image creating means.

As described above, since the command information is reconfigured according to the free memory size, the occurrence of a memory overflow error can be suppressed at low cost.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is an image forming apparatus which interprets image information created by an information processing apparatus, develops it into bitmap data, and outputs it. Necessary memory calculating means for calculating the work memory amount and intermediate image memory amount necessary for creating an intermediate image for each command, a free memory amount obtaining means for obtaining an available memory amount, a necessary memory calculating means and a free memory amount obtaining means Overflow determining means for determining whether there is a memory shortage, a command reconstructing means for reconstructing a command of image information based on a result of the determination by the overflow determining means, and an intermediate image creating means for creating an intermediate image from the image information. Since the command information is reconfigured according to the available memory size, a memory overflow error can be generated at low cost. It has the effect that it is possible to suppress the raw.

According to a second aspect of the present invention, in the first aspect of the present invention, the overflow determining means is an image forming apparatus which functions when processing bitmap data or raster data of image information. In addition, since command reconstruction is not applied to a vector command that consumes less memory, the processing time can be shortened.

According to a third aspect of the present invention, in the first or second aspect, the command reconstructing means is an image forming apparatus for dividing bitmap or raster image information in the sub-scanning direction. Since the reconstruction in the main scanning direction is not performed, the program structure is not complicated and the processing time can be reduced and the memory efficiency can be improved.

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, the command reconstructing means is configured to divide an image based on buffer information developed from an intermediate image into a bitmap. Since it is a device and is reconfigured in consideration of band buffer size information, it has an effect that it is possible to improve the intermediate image creation processing efficiency for each band.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the intermediate image creating means has an empty intermediate image memory amount obtained by the necessary memory calculating means. If the available memory amount obtained by the memory amount obtaining means is smaller than the available memory amount, the image forming apparatus secures the memory amount before command reconstruction as the intermediate image memory. Since the intermediate image data is secured as a continuous area at one time, This has the effect of improving memory efficiency and shortening the processing time.

According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the intermediate image creating means is configured to execute the intermediate image creation when the overflow determining means determines that the memory is insufficient. An image forming apparatus that secures a memory amount in a size that takes into consideration the average compression ratio of an intermediate image as an image memory. Since the memory is secured in a size that takes into account the average compression ratio, memory efficiency can be improved. It has the action of:

According to a seventh aspect of the present invention, there is provided an image forming method for interpreting image information created by an information processing apparatus, developing the image information into bitmap data, and outputting the bitmap data. Calculate the amount of work memory and intermediate image memory required for image creation, determine the amount of available memory, determine whether there is insufficient memory from the amount of work memory, the amount of intermediate image memory, and the amount of available memory. This is an image forming method in which the command of the image information is reconstructed based on the result of the determination as to whether it is insufficient, and an intermediate image is created from the image information. This has the effect that the occurrence of a memory overflow error can be suppressed at a low cost.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

In the present embodiment, a color laser beam printer suitable for applying the present invention will be described as an example. Note that the image forming apparatus to which the present invention is applied is not limited to a color laser beam printer, and it goes without saying that various other printers and the like can be applied.

FIG. 1 is a block diagram showing the configuration of main parts of an image forming apparatus according to an embodiment of the present invention for each functional block.

As shown in FIG. 1, the image forming apparatus 101
Are an IF unit 102, a reception buffer 103, a command analysis unit 104, a central management unit 105, an intermediate data generation unit 106, a work memory 107, a bitmap generation unit 108, a band buffer 109, an engine output A unit 110, an engine 111, and a printer setting unit 112 are provided.

Next, the function of each section of the image forming apparatus 101 will be described.

The IF unit 102 controls data transmission and reception with the host computer, receives PDL as print information from the host computer, and
Of the received PDL data, and notifies the command analysis unit 104 of the data reception notification and the data storage destination address.

The command analysis unit 104 receives the data from the reception buffer 1
The PDL data stored in the PDL data is read out, the command is analyzed, and if the command is a command for setting a printing operation for each print job, the setting is notified to the central management unit 105. The command is passed to the data generation unit 106. The central management unit 105 manages and sets the print job.

The intermediate data generator 106 receives the drawing command, converts the drawing command into a DL, which is an intermediate language, and stores it in the work memory 107.

The intermediate data generation unit 106 manages the pages. When the creation of the DL for one page is completed, the intermediate data generation unit 106 issues a DL creation end notification including the DL storage destination address to the central management unit 105.

The central management unit 105 includes the intermediate data generation unit 1
When receiving the DL creation end notification from the server 06, the control unit issues a bitmap generation request to the bitmap generation unit 108.

Upon receiving a bitmap generation request including the DL storage destination address from the central management unit 105, the bitmap generation unit 108 extracts the DL stored in the work memory 107 and develops the bitmap in the band buffer 109. When the bitmap development is completed on the band buffer 109 within a range where the data output to the engine is not delayed, a preparation completion notification is issued to the central management unit 105. And
After issuing a preparation completion notification to the central management unit 105, deployment to the remaining band buffers 109 is started.

When the central management unit 105 receives the notification from the bitmap generation unit 108, the engine output unit 110
Request engine output. In response to this, the engine output unit 110 sequentially extracts bitmap data from the band buffer 109 and outputs the bitmap data to the engine 111.

In the engine 111, the engine output unit 11
A CMYK image is formed on a photoconductor based on output data from 0, and the formed image is transferred onto paper to form an image.

When the image formation is completed and the paper is discharged, the engine output unit 110 sends a print completion notification to the central management unit 105. The printer setting unit 112 receives settings from the user, notifies the central management unit 105 of the user settings,
The central management unit 105 changes the settings of the printer.

Next, the configuration of the intermediate data generating unit 106 for reconfiguring the PDL command according to the free space of the work memory in the color laser beam printer of the present embodiment configured as described above will be described with reference to FIG. The processing procedure will be described with reference to FIG.

The intermediate data generating unit 106 includes a command determining unit 201, a necessary memory calculating unit 202, an overflow determining unit 203, and a command reconstructing unit 204.
Band information obtaining means 205, free memory amount obtaining means 206, bitmap intermediate image generating means (intermediate image generating means) 207, and vector intermediate image generating means 2
08.

Next, the function of each unit of the intermediate data generation unit 106 will be described with reference to the flowchart shown in FIG.

The command determining means 201 analyzes the command and determines whether the command is a bitmap drawing command.
It is determined whether the command is a vector-based drawing command and processing is performed (S301).

The necessary memory calculating means 202 is called when the command is a bitmap drawing, and DL size information (hereinafter "DLSIN") required for bitmap drawing.
FO ". ) And bitmap work memory size information for DL creation (hereinafter, “BMWINF”)
O ". ) Is calculated from the bitmap drawing command (S302). Note that the DL size information is DL size information related to a processing command unit.

The overflow determining means 203 obtains the free memory size of the work memory 107 (hereinafter referred to as “AVMS”) from the free memory amount obtaining means 206 (S 303), and obtains D obtained by the necessary memory calculating means 202.
A comparison is made between the L size information and the bitmap work memory size information for creating the DL to determine whether or not the memory is insufficient (S304).

When the overflow determining means 203 determines that the memory is insufficient, the command reconstructing means 204
Band buffer size information is obtained from the band information obtaining means 205 (S305), the band buffer size information, bitmap work memory size information and DL size information for DL creation obtained by the necessary memory calculation means 202, and free memory The bitmap drawing command is reconfigured based on the free memory size of the work memory 107 obtained by the amount obtaining means 206 so that drawing can be performed without causing memory shortage (S306).

Bitmap type intermediate image creating means 207
Creates a DL from the bitmap drawing command, stores it in the work memory 107, acquires band buffer size information from the band information acquiring unit 205, calculates the associated band and area, and generates an intermediate data Is registered in a band information management unit (not shown) that manages each band (S307).

The vector-based intermediate image creating means 208 creates a DL from the vector drawing command, stores it in the work memory 107, and stores the DL in the work memory 107.
5 to obtain band buffer size information, calculate related bands and areas, and register them in the band information management unit (S310).

Next, the command reconstructing procedure of the command reconstructing means 204 in the intermediate data generator 106 will be described with reference to the flowchart of FIG.

The command reconstructing means 204 obtains bitmap work memory size information and DL size information for DL creation obtained by the necessary memory calculating means 202 (S401), and further obtains the work obtained by the memory amount obtaining means 206. The free memory size of the memory 107 is obtained (S4
02) It is determined whether the DL size information is smaller than the free memory size of the work memory 107 (S403).

The DL size information is stored in the work memory 1
If it is determined that the memory size is smaller than the free memory size of 07, an instruction to secure the DL memory area in the work memory area 107 with the size of the DL size information is added to the command information (S404).

Next, based on the band buffer size information acquired by the band information acquisition means 205, a bitmap work memory size (hereinafter, referred to as "BMWINF") required for DL creation for each band buffer included in the command drawing range.
O. n ". n is a band buffer number) (S405), and the BMWINFO.
It is determined for each band buffer whether n is smaller than a value obtained by subtracting the DL size information from the free memory size of the work memory 107 (S406).

In S406, for all the band buffers, the BMWINFO.
If it is determined that n is smaller than the value obtained by subtracting the DL size information from the free memory size of the work memory 107, the command is reconfigured based on the band buffer (S40).
7). Also, in S406, the BMW INFO. If it is determined that n is larger than the value obtained by subtracting the DL size information from the free memory size of the work memory 107 for one or more band buffers, the bitmap work memory size required for DL creation is set to the free memory size of the work memory 107. The command is reconfigured so as to be within 80% of the value obtained by subtracting the DL size information from (the ratio is referred to as α) (S40).
8). The value of α is not limited to 80%,
Different values may be used depending on the system as long as the memory is not insufficient.

If it is determined in step S403 that the DL size information is larger than the free memory size of the work memory 107, the bitmap work memory size required for creating the DL is determined by the range obtained from equation (1). ), And an instruction to compress the DL bitmap is added to the command information when the DL is created (S
409).

D + (D × β) × Γ × Λ <(AVMS-DLSINFO × γ) (Expression 1) β: Enlargement / reduction ratio to printer resolution Γ: Color conversion coefficient (for conversion from RGB to CMYK) ４: gradation conversion coefficient (１ ／: conversion from 8 bits to 1 bit for each color) γ: average compression ratio In step S403, the DL size information indicates the free memory size of the work memory 107. Is determined to be smaller, but this is not a limitation.
For example, the determination may be made based on what percentage or less of the free memory size of the work memory 107 is the DL size information.

Next, an example of S408 in FIG. 4 will be described with reference to FIGS. 5 and 6 as an example of command reconfiguration.

In FIG. 5, reference numeral 501 denotes bitmap command information created when the intermediate data generating unit 106 receives a bitmap drawing command. As shown in the figure, the bitmap command information 501 includes Xpoti, which is the upper left coordinate of the bitmap in the command coordinate system.
on502, Ypotion 503, srcWidth 504 representing the width of the bitmap, srcHeight 505 representing the height of the bitmap, and destWidth representing the width of the bitmap after drawing at the printer resolution.
506, destHeight 507 indicating the height of the bitmap after drawing at printer resolution, and pSrcBitmap 508 which is a pointer to bitmap data
And Reco indicating whether the command has been reconstructed or not.
nfig 509, TotalSepnum 510 indicating the number of divisions in the case of reconfiguration, and S indicating the number of the divided bitmap command information.
epnum 511, DL_org 512 indicating whether the memory for DL creation is to be secured at the size before reconfiguration, and DL_Co indicating whether to compress the bit map area of the DL.
mp513 and orgXpotio, which is the upper left coordinate of the bitmap in the command coordinate system before command reconstruction.
n514, orgYpotion 515, and srcrcWidt representing the width of the bitmap before command reconstruction
h516, orgsrc Height 517 representing the height of the bitmap before command reconstruction, orgdestWidth 518 representing the width of the bitmap after rendering at the printer resolution before command reconstruction, and bits after rendering at the printer resolution before command reconstruction. OrgdestHeight 519 indicating the height of the map, and porg as a pointer to bitmap data before command reconstruction
SrcBitmap 520.

In FIG. 6, reference numeral 601 denotes the received bitmap data.
Represents a print page area, and reference numerals 603 to 6
Reference numeral 09 denotes a band boundary when the page area is divided into band buffers, reference numeral 610 denotes an area when the received bitmap data 601 is drawn at the printer resolution, and reference numeral 611 denotes the start of bitmap drawing. The reference numerals 612 and 613 indicate S406.
BMWINF required for DL creation for each band buffer
O. n is D from the free memory size of the work memory 107
If it is determined that the value is larger than the value obtained by subtracting the L size information, it indicates a reconstruction boundary when reconstruction is performed in an area smaller than the band reference in S408.

Upon receiving the bitmap drawing command,
Bitmap command information 501 is created, each parameter in the bitmap command information 501 is set from the bitmap drawing command, and a pointer to the received bitmap data 601 is set in pSrcBitmap 508.

Then, the bitmap command information 501
The processing of S401 to S404 described above is performed, and S4
In FIG. 05, the amount of bitmap work memory when expanded into band 3 (areas represented by reference numerals 605 and 606) and band 4 (areas represented by reference numbers 606 and 607) is determined by the free memory size of the work memory 107. To DL
Assuming it was larger than the size information minus
In step S408, it is determined whether the bitmap work memory amount when the band 3 and the band 4 are created in half the area is smaller than 80% of a value obtained by subtracting the DL size information from the free memory size of the work memory 107, If it becomes smaller, it is determined that band 2 and band 3 are to be reconfigured with half the size of the band as the reconfiguration information, and the number of reconfigurations is set to 6, and the reconfiguration is performed sequentially.

First, band 2 (reference numerals 604 and 605)
The bitmap command information 501 for the bitmap area included in the bitmap command information 501 is created, and the Xpotion 50 of the bitmap command information 501 is created.
2 and 503, the upper left coordinates of the bitmap included in the band 2 area in the command coordinate system are set.
rcWidth 504 sets the width of the bitmap included in the band 2 area, srcHeight 505 sets the height of the bitmap included in the band 2 area,
The width of the bitmap after drawing is set in the destinationWidth 506 with the printer resolution included in the band area 2,
The height of the bitmap after drawing is set to the destination height 507 at the printer resolution included in the band area 2, the pointer to the bitmap data is set to pSrcBitmap 508 as it is, and the Reconfig5
09 is set to a value (TRUE) indicating that it is reconfigured, TotalSepnum 510 is set to 6 because it has been reconfigured to 6, and Sepnum 511 is set to 1 to indicate that it is the first one. DL_org512
In step S403, a value (TRUE) indicating that the DL size can be secured in the original size is set, and DL_Com
In p, a value (0) indicating that the DL bitmap data is not compressed is set, and the corresponding original value is set in 514 to 520.

For band 3, first, bitmap command information is created at the boundary represented by reference numerals 605 and 612, and then bitmap command information is created at the boundary represented by reference numerals 612 and 606. Band 4 is created in the same manner as band 2. Band 5 is created in the same manner as band 2.

Next, the processing procedure of the bitmap intermediate image creating means 207 in the intermediate data generating section 106 will be described with reference to the flowchart of FIG.

Bitmap type intermediate image creating means 207
Acquires the bitmap command information 501 reconstructed by the command reconstructing means 204 or the bitmap command information 501 not reconstructed (S70).
1), a memory size required for bitmap work development is obtained from the bitmap command information 501, and a bitmap work memory is obtained from the work memory 107 (S).
702), the data is developed in the bitmap work memory based on the bitmap command information 501 (S703). When the data is expanded on the bitmap work memory, when the bitmap image of the bitmap command information 501 is a palette color, it is converted into 8-bit data for each of RGB, and when compressed, decompressed and stored in the bitmap work memory. Perform deployment.

Next, it is determined from the bitmap command information 501 whether to compress the bitmap image when creating the DL (S704). If it is determined that the bitmap image of the DL is to be compressed, the DL size is reduced to the average compression ratio γ. The DL memory is secured in a size multiplied by (S705). For example, if the average compression ratio in arithmetic coding is 25%, a DL memory with a size of 25% of the required DL size is secured without compression.

Further, the bitmap image expanded in the bitmap work memory is subjected to color conversion into CMYK, 1-bit area gradation conversion by dither processing, enlargement / reduction processing, and compression processing. DL secured
The data is developed in the memory (S706).

Then, in S706, it is determined whether or not the compressed data can be completely stored in the DL memory secured in S705 (S707).
05 is executed to secure a DL memory, and the DL that cannot be accommodated in S706 is expanded.

In step S704, if the bitmap image is not compressed at the time of creating the DL, or if it is reconstructed by the command reconstructing means 204, the bitmap command information 5
In the case where the DL memory is secured with the DL size before reconfiguration added to “01” and the command is not reconfigured by the command reconfiguration unit 204, the bitmap command information 501
The L size is calculated and secured (S708).

Further, the bitmap image developed in the bitmap work memory is subjected to color conversion into CMYK, 1-bit area gradation conversion by dither processing, and enlargement / reduction processing to the DL memory secured in S708. It is developed (S709). If the command has been reconstructed by the command reconstructing means 204, a DL memory is reserved only for the first bitmap command information in S708, and if it is expanded in the bitmap work memory in S703, Xpot
ion502 and Ypotion503 are orgXpot
The difference between the ionic 514 and the orgYpotion 515 is calculated, and the bitmap data 601 linked to the pSrcBitmap 508 is sequentially expanded for each line, and the data after the difference is expanded to the bitmap work memory. In addition, in S706 and S709, the data is expanded in the DL memory, band buffer size information is obtained from the band information obtaining unit 205, related bands and regions are calculated, and registered in the band information management unit.

As described above, according to the present embodiment,
Since the command information is reconfigured in accordance with the available memory size, there is an effect that the occurrence of a memory overflow error can be suppressed at low cost.

According to the present invention, a recording medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and a computer of the system or apparatus stores the program stored in the recording medium. Needless to say, this can also be achieved by reading and executing the code. In this case, the program code itself read from the recording medium realizes the function of the above-described embodiment, and the recording medium on which the program code is recorded constitutes the present invention.

As a recording medium for supplying such a program code, for example, a flexible disk (floppy (registered trademark) disk), hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used. Also, the present invention is configured in a form in which a program code is stored in these recording media placed on a server such as an Internet provider and the program code is provided via the Internet.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the operating system (OS) running on the computer based on the instruction of the program code. It is needless to say that the system may perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the recording medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that a CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

[0066]

As described above, according to the present invention, since the command information is reconfigured according to the available memory size, it is possible to suppress the occurrence of a memory overflow error at low cost. Effects can be obtained.

If the overflow judging means is made to function when processing bitmap data or raster data of the image information, the command reconfiguration is not applied to the vector commands which consume less memory, so that the processing time is reduced. An effective effect that it becomes possible to obtain the effect can be obtained.

If the bitmap or raster image information is divided in the sub-scanning direction, reconstruction in the main scanning direction is not performed, so that the program structure is not complicated and the processing time is shortened and the memory efficiency is improved. An effective effect that it becomes possible to achieve this is obtained.

If the image is divided based on the buffer information developed from the intermediate image into the bitmap, the image is reconstructed in consideration of the band buffer size information, so that the efficiency of the intermediate image generation processing for each band can be improved. An effective effect that it becomes possible is obtained.

If the intermediate image memory amount obtained by the necessary memory calculating unit is smaller than the available memory amount obtained by the free memory amount obtaining unit, the intermediate image creating unit secures the memory amount before command reconstruction as the intermediate image memory. By doing so, the intermediate image data is secured as a continuous area at one time, so that an effective effect of improving the memory efficiency and shortening the processing time can be obtained.

If the overflow judging means judges that the memory is insufficient, if the memory size is secured as the intermediate image memory in consideration of the average compression ratio of the intermediate image, the memory is secured in a size considering the average compression ratio. Is performed, so that an effective effect that memory efficiency can be improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an image forming apparatus according to an embodiment of the present invention for each functional block;

FIG. 2 is a block diagram functionally showing a configuration of an intermediate data generation unit in the image forming apparatus of FIG.

FIG. 3 is a flowchart showing a processing procedure by an intermediate data generation unit in FIG. 2;

FIG. 4 is a flowchart showing a command reconfiguration procedure in a command reconfiguration unit in the intermediate data generation unit in FIG. 2;

FIG. 5 is an explanatory diagram showing bitmap command information in the image forming apparatus of FIG. 1;

FIG. 6 is an explanatory diagram showing an example of a bitmap command reconstruction in the image forming apparatus of FIG. 1;

FIG. 7 is a flowchart showing an intermediate image creating procedure in a bitmap intermediate image creating unit in the intermediate data generating unit in FIG. 2;

[Explanation of symbols]

202 Required memory calculation means 203 Overflow determination means 204 Command reconstruction means 206 Free memory amount acquisition means 207 Bitmap intermediate image creation means (intermediate image creation means)

Claims (7)

[Claims] 1. An image forming apparatus for interpreting image information created by an information processing device and developing and outputting the same as bitmap data, comprising: a work memory amount necessary for creating an intermediate image for each command of image information; A required memory calculating unit for calculating an image memory amount, a free memory amount obtaining unit for obtaining an available memory amount, and an overflow determining unit for determining whether there is a memory shortage from the required memory calculating unit and the free memory amount obtaining unit. An image forming apparatus comprising: command reconstructing means for reconstructing a command of image information based on a result of the judgment by the overflow judging means; and intermediate image creating means for creating an intermediate image from the image information. . 2. An image forming apparatus according to claim 1, wherein said overflow judging means functions when processing bitmap data or raster data of the image information. 3. The image forming apparatus according to claim 1, wherein said command reconstructing means divides bitmap or raster image information in a sub-scanning direction. 4. The image forming apparatus according to claim 1, wherein said command reconstructing means divides the image data based on buffer information developed from an intermediate image into a bitmap. 5. The intermediate image creating means, if the intermediate image memory amount obtained by the necessary memory calculating means is less than the available memory amount obtained by the free memory amount obtaining means, a command reconfigured as an intermediate image memory. The image forming apparatus according to any one of claims 1 to 4, wherein a memory amount is secured. 6. The intermediate image creating means secures a memory amount with a size considering an average compression ratio of the intermediate image as an intermediate image memory when the overflow determining means determines that the memory is insufficient. The image forming apparatus according to claim 1. 7. An image forming method for interpreting image information created by an information processing device and developing and outputting the same as bitmap data, comprising: a work memory amount necessary for creating an intermediate image for each command of image information; Calculate the amount of image memory, determine the amount of available memory, determine whether there is insufficient memory from the amount of work memory, the amount of intermediate image memory, and the amount of available memory. An image forming method, comprising: reconstructing a command of image information based on the original, and creating an intermediate image from the image information.