JPH09252412A - Image processor and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process efficiently print data in which a color image and a monochromatic image are in existence in mixture. SOLUTION: Print data received from a host computer 101 are stored in a buffer 111 and interpreted by a page description language PDK interpreter 117 and decomposed into Y, M, C components. A control program 118 compares contents of image memories 113-115 to decide whether or not there is any coincident content in them to manage the image memories based on the decision result. For example, when the contents of all the image memories 113-115 are coincident (black monochromatic image), the image memories (M) 114 and (C) 115 are released and used for expansion of succeeding print data, and the data expanded in the image memory (Y) are fed to a printer engine 120 as three color Y, M, C drawn data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and a control method thereof, and more particularly to an image processing apparatus capable of forming an image by mixing a plurality of element colors and a control method thereof.

[0002]

2. Description of the Related Art In a system in which a document or the like created by a computer or the like is output from a printer, print data supplied from the computer or the like to the printer generally comprises a command group in which document information is described as image information. A printer that receives such print data interprets it in a command interpreter, develops it into a bitmap image, and outputs it as a visible image on a recording medium. Such a command system is called a page description language (PDL), and typical examples thereof include PostScript and Capsl.

FIG. 9 shows an example of an original created by a computer. This document consists of 6 pages 901 to 906, of which pages 1, 2, and 6 are black and white character documents, and pages 3, 4, and 5 are color documents. When such an original document is converted into print data such as PDL as a color image and supplied to the printer, the printer processes all the print data for the six pages as a color image. That is, the printer decomposes all of the print data of page 6 into yellow, magenta, and cyan components, forms images of respective separated colors, and combines them.

[0004]

However, in the above-mentioned conventional example, when a document in which color pages and black monochromatic pages are mixed is supplied to the printer as color print data, all pages are printed by the printer. Since it is processed as a page of, the printing process for a monochrome black page originally consumes unnecessary time.

This problem is not limited to the case where a black monochromatic page is treated as a color page, but even if the original is a color page, for example, the page does not include the yellow component, or the page includes only the yellow component. The same applies to cases such as pages.

The present invention has been made in view of the above problems, and it is an object of the present invention to efficiently output a captured image according to the color of the image.

[0007]

In order to solve the above problems, an image processing apparatus according to the present invention has the following features. That is, the image processing apparatus according to the present invention is an image processing apparatus capable of forming an image by mixing a plurality of element colors, and an image acquisition unit that acquires an image, and the acquired image is an image of the plurality of element colors. Selection means for comparing the respective contents of the images decomposed into the respective element colors with the decomposing means for decomposing into the above, the storing means for storing the image decomposed into the respective element colors in the memory medium, and selecting the image having the same content. Means, erasing means for substantially erasing other images from the memory medium while leaving at least one image selected by the selecting means, and image forming for forming an output image by referring to the memory medium. And means.

The image processing apparatus according to the present invention preferably further has the following features. That is, in the image processing apparatus according to the present invention, the image forming unit uses the at least one image instead of the other image when the other image is erased by the erasing unit, and outputs the output image. Is preferably formed.

Further, in the image processing apparatus according to the present invention, when the other image is erased by the erasing means, the next image obtained by the obtaining means is decomposed by the decomposing means, It is preferable to further include control means for controlling the storage means to store an image of a part of the element colors in an area secured by erasing the other image in the area of the memory medium.

Further, in the image processing apparatus according to the present invention, the image of the partial element colors stored by the storage means in the area secured by erasing the other image has the same element color as the other image. The image is preferably.

Further, the image processing apparatus according to the present invention substantially deletes the non-contents image from the memory medium, and the judgment means for judging the non-contents image among the images separated into the respective element colors. It is preferable to further include a deleting unit.

Further, in the image processing apparatus according to the present invention, the image forming means uses the at least one image instead of the other image when the other image is erased by the erasing means. To form an output image.

Further, in the image processing apparatus according to the present invention, when the other image is erased by the erasing means or the uncontented image is erased by the erasing means, The image is decomposed by the decomposing means, and an image of some element colors of the decomposed image is
It is preferable to further include control means for controlling the storage means to store the image in the area secured by erasing the other image or deleting the uncontented image in the area of the memory medium.

Further, in the image processing apparatus according to the present invention, the image of the partial element colors stored by the storage means in the area secured by erasing the other image has the same element color as the other image. It is preferable that the image of the partial element color stored in the area secured by deleting the uncontented image by the storage unit is an image of the same element color as the uncontented image. .

In the image processing apparatus according to the present invention, it is preferable that the element color is a separated color.

Further, in the image processing apparatus according to the present invention, it is preferable that the image forming means forms an output image by an electrophotographic method.

Further, in the image processing apparatus according to the present invention, it is preferable that the image forming means forms an output image by an ink ejection method.

Another image processing apparatus according to the present invention is
An image processing apparatus capable of forming an image based on a page description language by mixing a plurality of element colors, an image acquisition unit for acquiring an image, and an output image based on the content of the acquired image among the plurality of element colors And an image forming means for forming an output image by using the determined element color.

Another image processing apparatus according to the present invention preferably further has the following features. That is, in another image processing apparatus according to the present invention, the element color determining unit has a decomposing unit that decomposes the acquired image into images of the element colors, and based on the contents of the separated images of the element colors. ,
It is preferable to determine the element colors used to form the output image.

Further, in another image processing apparatus according to the present invention, the element color determining means further comprises a determining means for determining the presence or absence of the content of the image of each of the separated element colors, and based on the determination result. , It is preferable to determine the element color used to form the output image.

Further, in the other image processing apparatus according to the present invention, the element color determining means further includes a comparing means for determining whether or not the contents of the separated images of the respective element colors match. Based on the results, it is preferable to determine the element color used to form the output image.

Further, in another image processing apparatus according to the present invention, the element colors include separation colors, and the color separation means is
It is preferable to decompose the acquired image into the separated color image.

Further, in another image processing apparatus according to the present invention, the element color further includes black, and the element color determination means determines that the determination results of the determination means match the contents of images of all separation colors. If it is indicated that the element color is black, the element color used for forming the output image is preferably black.

Further, in another image processing apparatus according to the present invention, it is preferable that the element color determining means determines the element color to be used for each page of the acquired image.

Further, in another image processing apparatus according to the present invention, it is preferable that the image forming means forms an image by an electrophotographic method.

Further, in another image processing apparatus according to the present invention, it is preferable that the image forming means forms an image by an ink ejection method.

The image processing apparatus control method according to the present invention is an image processing apparatus control method capable of forming an image by mixing a plurality of element colors, and an image acquisition step of acquiring an image The decomposition step of decomposing the image into the images of the plurality of element colors, the storage step of storing the image decomposed into the element colors in the memory medium, and the respective contents of the images decomposed into the element colors are compared, Refer to the memory medium; a selecting step of selecting images having the same contents; an erasing step of substantially erasing other images from the memory medium while leaving at least one image selected by the selecting means. And an image forming step of forming an output image.

Another image processing apparatus control method according to the present invention is an image processing apparatus control method capable of forming an image based on a page description language by mixing a plurality of element colors, and acquires an image. An image acquisition step, and an element color determination step of determining an element color used to form an output image based on the content of the acquired image among the plurality of element colors
An image forming step of forming an output image using the determined element color.

Further, the computer-readable memory according to the present invention is a computer-readable memory containing a control program code of an image processing apparatus capable of forming an image by mixing a plurality of element colors, and an image acquiring step for acquiring an image. , The code of the decomposing step of decomposing the acquired image into the images of the plurality of element colors, the code of the storing step of storing the image decomposing into the element colors in the memory medium, and the decomposing into the element colors. A code of a selection step of comparing respective contents of images and selecting an image having the same contents, and at least one of the images selected by the selecting means is left and other images are substantially stored in the memory medium. And an image forming step code for forming an output image with reference to the memory medium.

Another computer-readable memory according to the present invention is a computer-readable memory containing a control program code of an image processing apparatus capable of forming an image based on a page description language by mixing a plurality of element colors. The code of the image acquisition step of acquiring the image and the code of the element color determination step of determining the element color used to form the output image based on the content of the acquired image among the plurality of element colors are determined. And a code of an image forming process for forming an output image using element colors.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 is a block diagram showing an example of the arrangement of a printer system according to this embodiment. The host computer 101 edits a document, a figure, a bitmap image, etc., generates PDL format print data, and supplies it to the printer 110. Printer 110
Receives print data supplied from the host computer 101 through the interface 111. The received print data is temporarily held in the buffer 111, and
Interpreted by the DL interpreter 117, decomposed into yellow (Y), magenta (M), and cyan (C) separated colors (element colors), and the image memory (Y) of the developing unit 112 respectively.
113, image memory (M) 114, image memory (C) 1
Deployed on 15. As element colors, yellow,
Colors other than magenta and cyan (for example, red and black) may be used.

The bitmap data developed on each image memory is supplied to the printer engine 120 as drawing data. The printer engine 120 includes a developing unit 112.
The image forming materials (ink, toner, etc.) of yellow (Y), magenta (M) and cyan (C) are mixed based on the drawing data supplied from the drawing data to form a color image. As an image forming method, an electrophotographic method, an ink discharge method, or the like is suitable.

The memory 116 includes a PDL interpreter 1
17, a control program 118, and a management table 119 are held. The codes of the PDL interpreter 117 and the control program 118 are supplied to the CPU 122, and C
It is executed by the PU 122. Control program 118
Controls print data reception, development, image output, and the like. The management table 119 also holds information for managing the image memory (developing unit 112).

FIG. 2 is a diagram schematically showing a configuration example of the expanding section 112. In the illustrated example, the image memory 113
.About.115 each have an area of m.times.n pixels, and one pixel is 8
Consists of bits. Memory controller 201
Supplies the separated color data input via the CPU bus to the corresponding separated color image memories 113 to 115.

The data determination unit 202 is provided in the image buffer 11
A flip-flop (FF) that is reset when the print data in 1 is expanded on the image memory 113 and is set when data other than "0" is written to the image memory 113.
202 a and indicates whether or not the image is expanded in the image memory 113 (whether data other than “0” is written).
The data determination units 203 and 204 are provided corresponding to the image memory (M) 114 and the image memory (C) 115, respectively, and have the same function as the data determination unit 202. For example, assuming that the print data includes only image data relating to the separated colors Y and M, no bitmap image is stored in the image memory (C) 115 (“0” is written), and the flip-flop is used. (FF) 204a is not set.

The control program 118 determines the image memories 113 to 115 according to the state of each flip-flop (FF).
The presence or absence of the bitmap image in the inside is judged, and the image memory in which the bitmap image does not exist is opened for developing the next print data. Further, the control program 118 compares the contents of the image memories 113 to 115, and if there is an image memory having the same content, at least one image memory among the image memories having the same content is left, and other images are stored. The memory is released for expanding the next print data. For example, when the contents of the image memory (Y) 113 and the contents of the image memory (M) 114 match, for example, the image memory (Y) 113 is left and the image memory (M) 114 is left.
Will be released. In addition, for example, the image memory 11
If the contents of 3 to 115 match (black monochromatic image),
For example, the image memory (Y) 113 is left and the other image memories (M) 114 and (C) 115 are opened.

FIG. 3 is a diagram schematically showing a configuration example of the management table 119. The management table 119 has flags for managing each image memory, that is, a development flag, an output flag, a data flag, and a replacement flag for each separated color of Y, M, and C.

The expansion flag is a flag which is set when the bitmap image of the corresponding separated color is expanded in the image memory and is reset when the printer engine 120 outputs the image. The output flag is set when the output processing is started, and when the corresponding image memory is released due to the matching of the contents of the image memory, when it is determined that the image memory has no content, or the output processing ends. This is a flag that is reset when you do. The data flag indicates the state (presence / absence of contents of the image memory) of the flip-flop (FF) regarding the corresponding separated color. The replacement flag is an image memory (Y) having the same contents as the opened image memory when one of the image memories (for example, M) is released due to the coincidence of the contents of the image memories (for example, Y and M).
Is a flag for instructing. The details of these flags will be described later.

Next, the flow of operation based on the control program 118 will be described. The control program has an expansion processing program that controls the image expansion processing and an output processing program that controls the image output processing. Note that the CPU 122 executes these programs independently.

FIG. 4 is a flow chart showing the flow of expansion processing by the expansion processing program. This expansion process is activated by storing print data in the buffer 111.

First, in step S401, the opened image memory is recognized based on the state of the output flag of the management table 119. In step S402, the print data (for example, one page) in the buffer 111 is decomposed into images of respective separated colors (Y, M, C), and step S40
In 3, the separated color image corresponding to the opened image memory (memory whose output flag is OFF) is drawn (the corresponding flip-flop is reset prior to drawing). It should be noted that it is desirable that the processing for decomposing / decompressing the print data is performed at the same time (that is, decomposing while decompressing), but the description is divided into two steps for convenience of explanation. Further, although the data flag may be controlled by software, there is a problem that the processing speed becomes slow, and it is preferable that the data flag is controlled by hardware corresponding to the above-mentioned flip-flop (FF).

In step S404, the expansion flag corresponding to the separated color that has been expanded is set in the image memory, and in step S405, it is determined whether the expansion has been completed for all separated colors based on the state of the expanded flag. If there is an undeveloped separated color, the process returns to step S401 to wait until the image memory of the undeveloped separated color is released, and if the development for all separated colors is completed, the process proceeds to step S406. In step S406, it is determined whether or not the next print data exists in the buffer 111. If the next print data exists, the process returns to step S401.

FIG. 5 is a flow chart showing the flow of output processing by the output processing program. Step S
At 501, the expansion flags of the management table 119 are monitored, and when all the expansion flags are turned on, it is determined that the expansion has been completed for all separation colors, and the process proceeds to step S502. In step S502, the all-deployment flag is reset and the all-output flag is set. The expansion process (from step S402) is prohibited by setting the output flag.

In step S503, the management table 11
Based on the state of the data flag of No. 9, it is determined whether or not there is an image memory with no content, and if there is an image memory with no content, the process proceeds to step S508 and the output flag of the corresponding separation color is reset (this No image of separated color is formed).

On the other hand, if all the data flags are ON, the process proceeds to step S504, and it is determined whether or not there is an image memory whose contents match. This determination is, for example,
The contents Yij, Mij, and Cij of each image memory may be read and compared for m × n pixels. The matching modes are as follows: 1) When two separated color images match (Yij =
Mij, Yij = Cij, or Mij = Cij),
2) When the images of the three separated colors match (Yij = Mi
j = Cij; black monochromatic image).

In order to speed up the processing, for example, Yi
When j and Mij are compared, the next combination (for example, Yij and Cij) is found at the time when the pixel Yij ≠ Mij is found.
It is preferable to make a comparison with respect to j). Further, this processing may be realized by hardware or software.

If the result of determination in step S504 is that there is a separated color with the same content, in step S505 at least one separated color among the separated colors with the same content is left, and the output flags of the other separated colors are reset. At the same time, as a replacement flag for the separation color for which the output flag has been reset, a flag indicating a separation color for which the output flag has not been reset (the at least one separation color) is set.

For example, the image memory 1 for the separated colors Y, M and C
When the contents of 13 to 115 are the same, for example, the contents of the image memory (Y) 113 of the separated color Y are left (the output flag remains ON), and the output flags of the other separated colors M and C (one of them is also acceptable). ) Is reset. Then, the replacement flags of the separated colors M and C for which the output flags have been reset are both set to Y. Resetting the output flag means substantially erasing the contents of the corresponding image memory, and by this reset, the image memory of the corresponding separated color is opened and used for the expansion processing (step S402-). You can

In step S506, the output flag is ON.
The contents of the image memory of the separated color of the printer engine 120
To form an output image. here,
For the separation color whose output flag is OFF (for example, Y), the corresponding replacement flag is referred to, and when a flag indicating another separation color is set as the replacement flag (for example, M). Indicates the contents of the separated color image memory (M) designated by the replacement flag, and the output flag OF
As the content of the separated color (Y) of F, the printer engine 120
(The content of the separated color M is shared by the separated colors Y and M).

Here, if the output flag is OFF and the replacement flag is "0" (reset state), it means that the image memory of the corresponding separated color has not been stored. Regarding the separated color, it is not necessary to transfer the data to the printer engine 120 (it suffices to notify that the data is uncontained). Therefore, when the printer engine 120 has a mechanism for forming an image in a frame sequential manner by, for example, an electrophotographic method,
It is possible to omit the output process for the uncontented surface (separated color).

In step S507, all output flags are reset and all replacement flags are reset, and the process returns to step S501 for output processing of the next page.

As described above, among the image memories having the common contents, at least one image memory is left, the contents of the other image memories are substantially erased, and it is utilized for the development of the next print data. As a whole, the time required to form the output image can be shortened. In particular, when the contents of the image memories of all the separated colors match (black single color image), the image memories of the two separated colors can be used for developing the next print data, and a remarkable effect is obtained.

<Second Embodiment> In the present embodiment, four color image forming materials (ink, toner, etc.) of yellow (Y), magenta (M), cyan (C), and black (K) are used. The present invention relates to a printer that forms an image by using the printer engine 120, and the configuration of a printer engine 120 and the configuration of an output processing program are different from those in the first embodiment. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 6 is a block diagram showing a configuration example of the printer system according to this embodiment. In the present embodiment, the printer engine 120 has a function of forming an image using an image forming material of four colors of yellow (Y), magenta (M), cyan (C), and black (K), When the print data is analyzed and it is determined that the image to be output is a black monochromatic image, the image is output using only the black (K) image forming material. In this case, there is no need to perform output processing for the separated colors Y, M, C,
The processing can be made efficient. This configuration is extremely effective when the printer engine 120 has a mechanism for forming an image in a frame sequential manner by an electrophotographic method or the like.

FIG. 7 is a flow chart showing the flow of output processing by the output processing program according to the present embodiment. In step S701, the contents (Yij, Mij, Cij) of the image memories of the respective separated colors are compared for m × n pixels, and if there is no image memory having the same contents, the process proceeds to step S506, and the image memories of all separated colors are compared. If the contents of (1) match (black monochromatic image), the process proceeds to step S702, 2
If the contents of the image memories of the two separated colors (Y and M, Y and C, or M and C) match, the process proceeds to step S505.

FIG. 8 is a flowchart showing the flow of the monochromatic image output processing in step S702. First, in step S801, at least one separation color (Y in the illustrated example) is left, and output flags of other separation colors (M and C in the illustrated example) are reset (corresponding image memory is set). Open). As a result, the next print data expansion process (from step S402) can be executed.

Next, in step S802, the contents of the image memory (Y) 113 whose output flag is ON are regarded as black (K) image data and the printer engine 1
Transfer to 20. In this case, the printer engine 120
Does not process separated colors Y, M, and C,
The processing is streamlined. In particular, the printer engine 120
For example, in the case of having a mechanism for forming an image in a frame sequential manner by an electrophotographic method or the like, since no image is formed on the surfaces of the separated colors Y, M, and C, the effect of shortening the formation time of the output image is great.

As described above, by managing the image memory based on the contents of the image memory for each separated color, the image memory can be used efficiently, and as a result, the time required for image output is shortened. To be done.

Further, when processing print data including a color image and a black monochromatic image, the black monochromatic image is identified based on the content of each separated color, and the image is formed using only the black image forming material. Is output, the output process can be speeded up.

In the above description, yellow,
An example is shown in which an image memory for storing magenta and cyan data is provided, and an image is decomposed into respective component color components, but the present invention decomposes an image into R, G, and B element color components. The same can be applied to cases.

Further, even when the present invention is applied to a system composed of a plurality of devices (for example, host computer, interface device, reader, printer, etc.), a device composed of one device (for example, copying machine, It may be applied to a facsimile machine).

Another object of the present invention is to supply a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to supply a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy 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.

Further, by executing the program code read by the computer, not only the functions of the above-described embodiment are realized, but also the OS (operating system) running on the computer based on the instruction of the program code. It is needless to say that this also includes a case where the above) performs a part or all of the actual processing and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage 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 the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0068]

As described above, according to the present invention,
The captured image can be efficiently output according to the color of the image.

[0069]

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration example of a printer system according to a first embodiment.

FIG. 2 is a diagram schematically showing a configuration example of a developing unit 112.

FIG. 3 is a diagram schematically showing a configuration example of a management table 119.

FIG. 4 is a flowchart showing a flow of expansion processing by a expansion processing program.

FIG. 5 is a flowchart showing a flow of output processing by an output processing program.

FIG. 6 is a block diagram showing a configuration example of a printer system according to a second embodiment.

FIG. 7 is a flowchart showing a flow of output processing by an output processing program according to the second embodiment.

FIG. 8 is a flowchart showing a flow of a monochrome image output process of step S702.

FIG. 9 is an example of a document created by a computer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H04N 1/46 H04N 1/46 Z

Claims (24)

[Claims] 1. An image processing apparatus capable of forming an image by mixing a plurality of element colors, comprising image acquisition means for acquiring an image, and decomposing means for decomposing the acquired image into images of the plurality of element colors. Storage means for storing an image separated into each element color in a memory medium, selection means for comparing respective contents of the images separated into each element color, and selecting an image having the same content; And an image forming unit for forming an output image with reference to the memory medium, the erasing unit substantially erasing at least one image selected from the other images from the memory medium. An image processing device characterized by: 2. The image forming unit forms the output image by using the at least one image instead of the other image when the other image is erased by the erasing unit. The image processing apparatus according to claim 1. 3. When the other image is erased by the erasing unit, the next image acquired by the acquiring unit is decomposed by the decomposing unit, and an image of a partial element color of the decomposed image is displayed. 3. The image processing apparatus according to claim 1, further comprising a control unit that controls the storage unit so that the image is stored in an area secured by erasing the other image in the area of the memory medium. . 4. The image of the partial element color stored by the storage means in an area secured by erasing the other image is an image of the same element color as the other image. The image processing apparatus according to claim 3. 5. A determination means for determining a non-content image among the images decomposed into the respective element colors, and a deletion means for substantially deleting the non-content image from the memory medium are provided. The image processing apparatus according to claim 1, which is characterized in that. 6. The image forming means forms an output image by using the at least one image instead of the other image when the other image is erased by the erasing means. The image processing apparatus according to claim 5. 7. When the other image is erased by the erasing means or when the uncontented image is deleted by the deleting means, the next image acquired by the acquiring means is decomposed by the decomposing means, Control for controlling the storage means so as to store an image of a part of the element color of the decomposed image in an area secured by erasing the other image or deleting the uncontented image in the area of the memory medium The image processing apparatus according to claim 5, further comprising means. 8. The image of the partial element color stored by the storage means in the area secured by erasing the other image is an image of the same element color as the other image, 8. The image according to claim 7, wherein the image of the partial element colors stored in the area secured by deleting the image by the storage unit is an image of the same element color as the uncontent image. Processing equipment. 9. The image processing apparatus according to claim 1, wherein the element color is a separation color. 10. The image processing apparatus according to claim 1, wherein the image forming unit forms an output image by an electrophotographic method. 11. The image processing apparatus according to claim 1, wherein the image forming unit forms an output image by an ink ejection method. 12. An image processing apparatus capable of forming an image based on a page description language by mixing a plurality of element colors, the image acquiring unit acquiring the image, and the content of the image acquired from the plurality of element colors. An image processing apparatus comprising: an element color determining unit that determines an element color used to form an output image based on the image; and an image forming unit that forms an output image using the determined element color. . 13. The element color determining means has a decomposing means for decomposing the acquired image into images of the element colors, and forms an output image based on the contents of the decomposed images of the element colors. The image processing apparatus according to claim 12, wherein the element color to be used is determined. 14. The element color determining means further comprises a determining means for determining the presence or absence of the content of an image of each of the separated element colors, and an element used to form an output image based on the determination result. The image processing apparatus according to claim 8, wherein the color is determined. 15. The element color determining means further comprises a comparing means for determining whether or not the contents of the separated images of the respective element colors match, and for forming an output image based on the comparison result. 15. The image processing apparatus according to claim 13 or 14, wherein the element color used for is determined. 16. The image processing apparatus according to claim 15, wherein the element color includes a separated color, and the color separation unit separates the acquired image into the separated color image. 17. The element color further includes black, and the element color determination means outputs the output image when the determination result by the determination means indicates that the contents of the images of all separation colors match. The image processing apparatus according to claim 16, wherein the element color used to form the image is black. 18. The image processing apparatus according to claim 12, wherein the element color determining unit determines the element color to be used for each page of the acquired image. . 19. The image processing apparatus according to claim 12, wherein the image forming unit forms an image by an electrophotographic method. 20. The image processing apparatus according to claim 12, wherein the image forming unit forms an image by an ink ejection method. 21. A control method of an image processing apparatus capable of forming an image by mixing a plurality of element colors, the image acquiring step of acquiring an image, and the acquired image is decomposed into the images of the plurality of element colors. A decomposing step, a storing step of storing an image decomposed into each element color in a memory medium, a selection step of comparing respective contents of the images decomposed into each element color, and selecting an image having the same content, An erasing step of substantially erasing other images from the memory medium while leaving at least one image selected by the selecting means, and an image forming step of forming an output image with reference to the memory medium, A method for controlling an image processing apparatus, comprising: 22. A method of controlling an image processing apparatus capable of forming an image based on a page description language by mixing a plurality of element colors, the method comprising: an image acquisition step of acquiring an image; An element color determining step of determining an element color used to form an output image based on the content of the image, and an image forming step of forming an output image using the determined element color. A method for controlling an image processing apparatus. 23. A computer-readable memory containing a control program code of an image processing apparatus capable of forming an image by mixing a plurality of element colors, the code of an image acquisition step of acquiring an image, and the acquired image The code of the decomposition step of decomposing into an image of a plurality of element colors, the code of the storage step of storing the image decomposed into each element color in the memory medium, and comparing the respective contents of the image decomposed into each element color, A code of a selecting step of selecting an image whose contents match, and a code of an erasing step of substantially erasing other images from the memory medium while leaving at least one image selected by the selecting means, And a code for an image forming process for forming an output image with reference to the memory medium. 24. A computer-readable memory containing a control program code of an image processing apparatus capable of forming an image based on a page description language by mixing a plurality of element colors, the code being an image acquisition step for acquiring an image, An element color determination step code that determines an element color used to form an output image based on the acquired image content of the plurality of element colors, and an image that forms an output image using the determined element color A computer-readable memory comprising: a forming process code;