JPH07140951A - Method of displaying print image - Google Patents

Abstract

PURPOSE:To eliminate the need for minutely segmenting an image area and to reproduce a color of a superposing part relatively, faithfully when print image areas superposing each other are displayed on a display device. CONSTITUTION:Related to respective color components of YMCK, an order of density values of image areas R1-R6 is obtained, and the YMCK data are overwritten on a first frame memory in order of the low density value. The YMCK data are converted to the RGB data to be stored in a second memory. Then, the image is displayed according to the RGB data stored in the second frame memory. When the image area is revised, the YMCK data and the RGB data are updated related to respective pixels within the range of the image areas in before and after the revision, and the image is redisplayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of displaying a plurality of image areas in which uniform colors are expressed by a plurality of printing color components on a display means, and more particularly, to display overlapping image areas. The present invention relates to a method of displaying an included image in a state close to a printed matter.

[0002]

2. Description of the Related Art In recent years, soft packaging materials such as vinyl and cellophane, on which graphics and characters are gravure printed, have been used as food packages. It is common to print a plurality of colors for color printing, but since the soft packaging material easily expands and contracts, so-called plate misregistration (displacement of positions between color plates) easily occurs. Therefore, a process called "nigage" is performed in which adjacent image areas are overlapped by several mm. FIG.
[Fig. 6] is an explanatory diagram showing an example of performing a niger process. FIG.
As shown in (a), two image areas Ra and R of uniform color
b are in contact with each other, and the second image area Rb is painted with a color having a stronger intensity than the first image area Ra. Here, the “color intensity” is an intensity defined in advance as an order such as Y <M <C <K in the YMCK color system, for example.

In such a case, the first image area Ra is expanded to the second image area R as shown in FIG. 16 (b).
A nigue region Rc that seems to sneak under b is formed. When the gravure printing is performed on the soft packaging material, the width of the nigue region Rc may be about 3 mm, which is considerably large enough to be visually recognized. In addition,
The nigue region Rc is expanded on the basis of the image region Ra, and the two regions Ra and Rc are usually represented by one figure data as a single image region. In other words, the image of FIG. 16B has two image regions (Ra +
It is represented by two graphic data representing Rc) and Rb, respectively.

In recent years, there is a demand for displaying an image as shown in FIG. 16 (b) on a display device such as a color CRT to judge the quality of the image. When displaying an image in which a plurality of image areas overlap each other on a display device, a color system (for example, YMCK color system) used at the time of printing is converted to a display color system (for example, RGB color system). There is a need. However, since the levels of the RGB components are determined by the combination of the YMCK components, conventionally, FIG.
As shown in FIG. 5, image areas Ra, Rc, (Rb-Rc) having at least one different YMCK color component are obtained, and these YMCK components are converted into RGB components.

[0005]

However, since the two image areas Ra and Rc were originally represented by one figure data as a single image area, FIG.
As described above, there is a problem in that it takes a considerable time to process new data for dividing the image area. Further, it is difficult to faithfully reproduce on the display device the color of the nigue region Rc where the two image regions (Ra + Rc) and Rb overlap each other without dividing the image region as shown in FIG.

The present invention has been made in order to solve the above-mentioned problems in the prior art, and when displaying overlapping print image areas on a display device, it is not necessary to divide the image areas into small pieces, and It is an object of the present invention to provide a method capable of relatively faithfully reproducing the colors of overlapping portions.

[0007]

In order to solve the above-mentioned problems, the method of the present invention comprises means for displaying a plurality of image areas in which uniform colors are represented by a plurality of printing color components. And (B) generating density order data indicating the order of the density values of the plurality of image areas for each of the plurality of printing color components, and (B) the plurality of printing operations. With respect to each of the use color components, the plurality of image areas are sequentially selected in the descending order of the density value indicated by the density order data, and the image data representing the density value of each pixel in the selected image area is set to the first image data. Overwriting the frame memory, and (C) converting the plurality of printing color components of the image data stored in the first frame memory into a plurality of display color components, and converting the plurality of display color components into a second frame memory. Memory Comprising that a step, and a step of displaying the image on the display means in accordance with image data stored in (D) the second frame memory.

Since the image data of a plurality of image areas is overwritten in the first frame memory in descending order of the density value for each printing color component, the image data finally stored in the first frame memory is , The image data reflects the color at the time of printing relatively faithfully. Further, since the image data of each image area may be sequentially overwritten, it is not necessary to divide each image area.

The method for displaying a printed image according to the present invention further includes (E) a step of changing one of the plurality of image areas,
(F) updating the density sequence data according to the density values of the printing color components of the changed image area, and (G) displaying the image data relating to the pixels within the range before the change of the image area to be changed. A step of clearing from the first frame memory,
(H) At least image areas having ranks after the changed image area are sequentially selected according to the density order data, and at least for each pixel in the range of the changed image area, the density of a plurality of printing color components is selected. Overwriting the first frame memory with image data representing the respective values, and (I) image data stored in the first frame memory for at least each pixel within the range of the changed image region. Converting a plurality of printing color components into a plurality of display color components and overwriting in the second frame memory; and (J) displaying an image on the display means according to the image data stored in the second frame memory. The process of re-displaying,
Is equipped with.

Since the image data in the range of the image area before the change is cleared from the first frame memory and the image data in the first frame memory is updated at least for each pixel in the range of the image area after the change, Even when the image area is changed, the image can be displayed again in a relatively short time.

[0011]

1 is a block diagram showing the configuration of an image processing system to which an embodiment of the present invention is applied. This image processing system includes a CPU 30, a ROM 32, and a RAM.
34, a graphic vector memory 36 for storing graphic vector data representing each image area, and a first frame memory 38 for storing image data represented by YMCK components.
And a color conversion circuit 4 for converting YMCK components into RGB components
0, a second frame memory 42 for storing image data represented by RGB components, a display controller 44, and a color CRT 46. The above-mentioned circuits other than the color CRT 46 are connected by a CPU bus.

FIG. 2 is an explanatory view showing an image to be processed in this embodiment. FIG. 2A shows only the contours of the six image areas R1 to R6. Also, FIG.
(B) shows the dot area ratio of each color component of YMCK for each image region.

FIG. 3 is an explanatory diagram showing the structure of graphic vector data of the first image region R1. As shown in FIG. 3A, the first image region R1 has six vectors V1 to V6.
In addition, as shown in FIG. 3B, the graphic vector data is composed of a header section and a vector data section. The header portion includes the data file name and the density value of each color component of YMCK (FIG. 2B). In the vector data section, each vector V1
Vector data representing each V6 is included.
Such graphic vector data is stored in the graphic vector memory 36 (FIG. 1).

FIG. 4 is a flow chart showing the processing procedure of the embodiment. In step S10, display image data representing an image including the image regions R1 to R6 is created based on the graphic vector data stored in the graphic vector memory 36. The process of step S10 is performed by the ROM
It is realized by the CPU 30 executing a software program stored in the RAM 32 or the RAM 34.

FIG. 5 is a flow chart showing the detailed procedure of step S10. In step S11, YMCK
For each color component, the six image areas R1 to R6 are sorted in ascending order of density value. FIG. 6 shows density order data DOR representing the result of sorting the Y component in the order of density values.
It is explanatory drawing which shows the structure of. The density sequence data is composed of a header part and an address pointer part. The header portion contains data indicating which of the four color components YMCK is. Further, in the address pointer portion, an address pointer indicating the start address of each image area is registered in the order of increasing density value. As shown in FIG.
As for the components, “R1,
R2, R4, R5, R3, R6 ". Similar density order data DOR is created for other color components. The density order data DOR is not limited to the data having such a structure, and may have any structure as long as it is the data indicating the order of the density values of the image region for each color component of YMCK.

In step S12 of FIG. 5, screen display data (hereinafter simply referred to as “image data”) reflecting all image areas is created in accordance with the density order data DOR and stored in the first frame memory 38. To do. FIG. 7 is an explanatory diagram showing the processing content of step S12. Figure 7
(A) shows six image regions R1 to R6 for the Y component.
6 shows the order of the density values of, which is indicated by the density order data DOR shown in FIG. Figure 7
FIG. 6B shows a state in which the graphic vector data of each image area is expanded into image data according to this order and is overwritten in the Y-component frame memory 38Y. That is, after the image data of the image areas R1 to R4 are sequentially written, the image data of the image area R3 is overwritten, and further the image data of the image area R6 is overwritten. In this way, since the image data is overwritten in the order of increasing density value, the image area with low density value is hidden by the image area with high density value and becomes invisible. The image finally obtained in this way shows the same state as that actually printed.

The process of step S12 is executed for each color component of YMCK, and the frame memory 3 for each color component is used.
Image data of each color component is stored in 8Y, 38M, 37C, and 38K.

As shown in FIG. 7, if the image data is overwritten in the order of decreasing density, as shown in FIG.
There is an advantage that it is not necessary to perform the processing of dividing the image area as shown in (c).

In step S13 of FIG. 5, the YMCK components of the image data stored in the frame memory 38 are converted into RGB components by the color conversion circuit 40, and the converted image data are stored in the second frame memory 42.

FIG. 8 is a block diagram showing the internal structure of the color conversion circuit 40. The color conversion circuit 40 includes a color conversion table 50, an OR circuit 52, and a color conversion calculation circuit 60. The color conversion arithmetic circuit 60 includes four look-up tables 61 to 64 and three adders 65, 66 and 67.

The color conversion calculation circuit 60 converts the YMCK component (hereinafter simply referred to as "YMCK data") of the image data read from the first frame memory 38 into the RGB component (hereinafter simply referred to as "RGB data"). It is a circuit that executes the operation of converting to (call). Look-up table 61-
64 outputs the value of the RGB data for each of the YMCK data. For example, the first lookup table 61 for the Y component outputs RGB data fYB (Y), fYG (Y), fYR (Y) for the Y component. The three adders 65 to 67 have the lookup tables 61 to 61, respectively.
Add the B components of the RGB data output from 64,
B component of output data (= fYB (Y) + fMB (M) + fCB
Calculate (C) + fKB (K)). In FIG. 8, for convenience of illustration, only three adders 65 to 67 for the B component are shown, but actually, the same three adders are provided for the G component and the R component, respectively. ing.

The RGB data obtained by the color conversion calculation circuit 60 is input to the color conversion table 50 and at the same time O
It is input to the R circuit 52. The OR circuit 52 takes the logical sum of the output of the color conversion table 50 and the output of the color conversion calculation circuit 60 and outputs it. As will be described later, since only one of the color conversion table 50 and the color conversion calculation circuit 60 is active, the OR circuit 52 outputs the RGB data of the active circuit as it is.

FIG. 9 is an explanatory diagram showing the structure of the color conversion table 50. The color conversion table 50 is configured as a lookup table that inputs YMCK data and outputs RGB data. However, the RGB data is not stored in advance, and the result calculated by the color conversion calculation circuit 60 (FIG. 8) is registered. Color conversion table 5
As the 0 data area, areas corresponding to all combinations of the values of the four YMCK data are reserved in advance. The color conversion table 50 further has a registration flag F. The registration flag F is a flag indicating whether or not RGB data corresponding to YMCK data is registered. That is, the registration flag F is set to 1 for YMCK data whose RGB data is registered in the color conversion table 50 once calculated by the color conversion calculation circuit 60, and the color conversion calculation circuit 60 executes the calculation even once. Registration flag F is 0 for YMCK data that has not been registered.
Is set to.

As the data area of the color conversion table 50, the areas corresponding to all combinations of the values of the four YMCK data are not secured in advance, and only the data related to the combination of the YMCK data which has been once subjected to the operation is added. You may do so.

10 and 11 are explanatory views for explaining the function of the color conversion circuit 40. Figure 10 shows the input Y
The case where the registration flag F for MCK data is 1 is shown. As shown in FIG. 10, the first frame memory 38
The YMCK components are read from Y, 38M, 38C, and 38K for each pixel and supplied to the color conversion table 50. However, illustration of the K component is omitted for convenience. In the case of FIG. 10, since the registration flag F is 1, the RGB data registered in the color conversion table 50 is given to and written in the second frame memories 42R, 42G, 42B. On the other hand, in the case of FIG. 11, since the registration flag F is 0, the color conversion calculation circuit 60 calculates and obtains RGB data, and the obtained RGB data is acquired by the second frame memory 42.
The data is written in R, 42G, and 42B and is registered in the color conversion table 50.

The details of the operation of the color conversion circuit 40 are as follows. As can be seen from FIG. 8, the first frame memory 38
The YMCK data read from the color conversion table 50
Entered in. When the registration flag F for the input YMCK data is 1 (already registered), the color conversion table 50
Outputs RGB data, but when the registration flag F is 0 (unregistered), the color conversion table 50 does not output RGB data.

The color conversion table 50 also supplies the signal of the registration flag F to the four look-up tables 61-64. The lookup tables 61 to 64 are disabled when the registration flag F is 1, and enabled when the registration flag F is 0. Therefore, the data is output from each of the lookup tables 61 to 64 only when the registration flag F is 0 (unregistered).
For example, for the B component, the lookup table 61
~ 64 to fYB (Y), fMB (M), fCB
(C) and fKB (K) are output, these are added by the three adders 65 to 67, and the B component of the output data (=
fYB (Y) + fMB (M) + fCB (C) + fKB (K)) is obtained. The RGB data thus obtained is given to the color conversion table 50 and registered, and is also supplied to the second frame memory 42 (FIG. 1) via the OR circuit 52.

As the color conversion method in the color conversion arithmetic circuit 60, various methods other than those described above can be adopted. In particular, when a complicated calculation such as interpolation calculation is performed by the color conversion calculation circuit 60, the use of the color conversion table 50 having the registration flag F as shown in FIG. 9 can reduce the time required for the color conversion process. It will be noticeable. For the color conversion processing, the software program is executed by the CPU3.
It can also be realized by executing 0.

As described above, step S13 (FIG. 5)
Upon completion of the color conversion in step S20 (FIG. 4)
At, the image is displayed on the color CRT 46 according to the image data of the second frame memory 42.

In step S30, the operator observes the displayed image and changes the image as necessary. Modifying an image includes modifying the shape of the image area, modifying the color within the image area, deleting the image area, and creating a new image area.

FIG. 12 is a flowchart showing the detailed procedure of step S30. In step S31, the operator gives an instruction to change the image while looking at the color CRT 46. In response to this instruction, the CPU 30 changes the graphic vector data (FIG. 3) of the image area to be changed.
In the following, the processing contents of step S30 will be sequentially described for the three cases of correcting the image area, deleting the image area, and creating a new image area.

FIG. 13 is an explanatory diagram showing the processing contents of step S30 when the image area is corrected. FIG.
In (a), the state in which the image region R1 is enlarged rightward in step S31 and the image region R1a indicated by the broken line is instructed to be corrected is shown.

Steps S32 to S37 are processes automatically executed under the control of the CPU 30. First, in step S32, the image area to be changed is reflected in the density sequence data DOR (FIG. 6). FIG. 13B shows processing when the density value of the Y component of the corrected image area R1a is set to an intermediate value between the density values of the other two image areas R2 and R4. That is, here, the address pointer of the image area R1 is registered at a position intermediate between the address pointers of the image areas R2 and R4.

In step S33, another image area that at least partially overlaps the image area before and after the change is searched.
Here, the “image area before and after the change” is meant to include both the image area R1 before the change and the image area R1a after the change.

When the shape or color of the image area is modified, both the image area before the change and the image area after the change exist, but when the image area is deleted, the image area after the change is not exist. When creating a new image area,
The image area before the change does not exist, and only the image area after the change exists. In the example of FIG. 13C, the image area R before the change
The sum area of 1 and the changed image area R1a is equal to the changed image area R1a. In step S33, this sum area R
Image regions R2 and R3 are searched as other image regions that at least partially overlap with 1a. Note that step S
In 33, vector data representing the shape of the overlapping portion OL (the hatched area in the drawing) between the image area before and after the change and the other image area is also created.

The determination process of the overlapping state of the image areas in step S33 is performed based on the vector data of each image area. Since such processing uses a well-known method used in two-dimensional computer graphics, its details are omitted in this specification.

In step S34, the YMCK data for each pixel within the range of the sum area of the image areas before and after the change is cleared. That is, in the image data stored in the first frame memory 38, the data value of the sum area of the image areas before and after the change is set to 0. At this time, the image area R1
It is not necessary to consider the overlap between the image area and other image areas, and all pixels included in the sum area have their YMC
K data is cleared.

In step S35, the changed image area R
The YMCK data for each pixel within the range of 1a is overwritten in the first frame memory 38.

In step S36, YM for each pixel in the overlap portion OL between the image area before and after the change and another image area.
The CK data is overwritten in the first frame memory 38. At this time, according to the order shown in the density order data,
Y of the image area whose rank is later than the changed image area R1a
Only MCK data is overwritten. In the example of FIG. 13B, the image regions R4 and R that are ranked lower than the image region R1
The YMCK data of the overlapping portion OL is overwritten for 5, R3 and R6. FIG. 13D shows the image area R1a after correction in steps S35 and S36 and YM of the overlapping portion OL.
The state in which the CK data is overwritten is shown.

As described above, when the image area is modified, if the YMCK data is updated only for the image area before and after the change and for the overlapping area of the image area before the change and the other image area, YMCK The processing time for updating the data can be shortened.

In step S37, YMC for each pixel in the range of the image area before and after the change (that is, the sum area)
The K data is color-converted into RGB data, and the obtained RGB data is overwritten in the second frame memory 42.

The updating process of the YMCK data and the RGB data for the overlapping part OL (steps S36 and S3) is performed.
7) may be executed not only for the pixels within the range of the overlapping portion OL but also for each pixel within the region of the circumscribed rectangle of the overlapping portion OL2.

When the RGB data is corrected in this way, the image is redisplayed on the color CRT 46 in step S20 of FIG.

As described above, in the processing of steps S32 to S37, since only the image data in the range of the image area before and after the change is changed, there is an advantage that the processing time required for redisplaying the image can be shortened. is there.

FIG. 14 is an explanatory diagram showing the processing contents of step S30 when the image area is deleted. 14
In (a), it is instructed that the image region R1 should be deleted in step S31. In addition, when deleting the image area, when correcting the image area (FIG. 13)
In, it can be considered that the corrected image region R1a does not exist.

In step S32, the density sequence data DO
The address pointer of the image area R1 is deleted from R (FIG. 14B). In step S33, the image area R3 is searched as another image area that overlaps the image area R1 before the change (FIG. 14C). Note that in step S33, vector data representing the overlapping portion OL1 of the image areas R1 and R3 is also created. In step S34, the YMCK data is cleared for each pixel within the range of the image area R1 before the change. When the image area is deleted as shown in FIG. 14, since the changed image area does not exist, step S
Nothing happens at 35. In step S36, the YMCK data for each pixel in the range of the overlap portion OL1 is
The first frame memory 3 according to the density sequence data DOR
8 is overwritten (FIG. 13 (d)). Then, in step S37, the YMCK data for each pixel in the range of the image area before and after the change is color-converted into RGB data, and the obtained RGB data is overwritten in the second frame memory 42.

FIG. 15 is an explanatory diagram showing the processing contents of step S30 when a new image area is created. In FIG. 15A, it is instructed that a new image area R7 should be created in step S31. In addition,
When a new image area is created, it can be considered that the image area before correction does not exist in the case of correcting the image area (FIG. 13).

In step S32, a new image area R7
Is added to the density order data DOR. Figure 15 (b)
Is the density of the Y component of the image area R7,
When the density of the Y component of 5 is in the middle, it indicates that the address pointer of the image area R7 is arranged between the address pointers of the image areas R4 and R5 in the density sequence data DOR.

In step S33, the changed image area R
Another image area R3 overlapping 7 is searched, and its overlapping portion O
L2 vector data is obtained. In step S34, the YMCK data for each pixel within the changed image area R7 is cleared. In step S35,
The YMCK data for each pixel in the changed image region R7 is written in the first frame memory 38. As a result, the color of the newly created image area R7 is reflected on the image in the first frame memory 38.

In step S36, the YMCK data for each pixel in the overlap portion OL2 is converted into the density sequence data DO.
The second frame memory 42 is overwritten according to the order shown in R (FIG. 15B). For example, as for the Y component, the Y of the portion of the overlapping portion OL2 of the image regions R5, R3, and R6 having the rank later than the new image region R7.
The MCK data is overwritten in this order. in this way,
If the YMCK data is overwritten only on the image regions of the new image region R7 and the subsequent images, the processing time required to redisplay the corrected image can be shortened. FIG. 15D shows the steps S35 and S
36 shows how the YMCK data is changed for the new image region R7 and the overlapping portion OL2 at 36.

In step S37, a new image area R7
For each pixel inside, YMCK data is converted into RGB data and written in the second frame memory 42.

As described above, when a new image area is created, it is assumed that the image area before the change does not exist and only the image area after the change exists, steps S32 to S37.
Is executed, and the RGB data for display is updated accordingly.

As described above, in the above embodiment, when the operator has instructed to change the image (correction, deletion, new creation of the image area), the color data of the image area before and after the change and the image area before and after the change The image after the change can be displayed again only by correcting the color data of the overlapping portion with the other image area. Therefore, there is an advantage that the image can be displayed again at high speed. In addition, such an advantage is
In step S10 described above, the YMCK data of the image areas are overwritten in order of density for each color component without dividing the overlapping image areas.

The present invention is not limited to the above embodiments, but can be implemented in various modes without departing from the scope of the invention, and the following modifications can be made.

(1) In the above embodiment, the four color components for printing are YMCK, but the present invention is also applied to the case where an image is represented by other color components for printing. It is possible. Further, the display color system is not limited to the RGB color system, and the present invention can be applied to a system using any display color system such as the YUV color system.

(2) In the above embodiment, the shape of the image area is drawn by a geometrical shape, but the present invention can be applied to an image area having an arbitrary shape.

[0057]

As described above, according to the first aspect of the present invention, it is not necessary to finely divide the image areas even when the overlapping print image areas are displayed on the display means, and the image areas overlap each other. The effect is that the color of a part can be reproduced relatively faithfully.

According to the invention described in claim 2,
Even if the image area is changed, there is an effect that the image can be displayed again in a relatively short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an image processing system for displaying an image by applying an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an image that is a processing target of the embodiment.

FIG. 3 is an explanatory diagram showing a vector forming an image area and a structure of graphic vector data thereof.

FIG. 4 is a flowchart showing a processing procedure of the embodiment.

FIG. 5 is a flowchart showing a detailed procedure of step S10.

FIG. 6 is an explanatory diagram showing the structure of density order data.

FIG. 7 is an explanatory diagram showing the processing content of step S12.

FIG. 8 is a block diagram showing an internal configuration of a color conversion circuit 40.

9 is an explanatory diagram showing the configuration of a color conversion table 50. FIG.

FIG. 10 is an explanatory diagram illustrating a function of a color conversion circuit 40.

FIG. 11 is an explanatory diagram illustrating a function of the color conversion circuit 40.

FIG. 12 is a flowchart showing a detailed procedure of step S30.

FIG. 13 is an explanatory diagram showing processing contents when an image area is corrected.

FIG. 14 is an explanatory diagram showing the processing contents when deleting an image area.

FIG. 15 is an explanatory diagram showing the processing contents when a new image area is created.

FIG. 16 is an explanatory diagram showing a conventional example of performing nigue processing.

[Explanation of symbols]

 30 ... CPU 32 ... ROM 34 ... RAM 36 ... Graphic vector memory 38 ... First frame memory 40 ... Color conversion circuit 42 ... Second frame memory 44 ... Display control unit 46 ... Color CRT 50 ... Color conversion table 52 ... OR Circuit 60 ... Color conversion operation circuit 61-64 ... Look-up table 65-67 ... Adder DOR ... Density order data F ... Registration flag OL, OL1, OL2 ... Overlapping part R1-R7 ... Image area

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G03F 1/00 L G06T 1/00 H04N 1/46 // G03F 3/10 A (72) Inventor Naohisa Nozawa No. 1 at Tenjin Kitamachi 4-chome, Tenjin Kitamachi, Horikawa-dori Teranouchi, Kamigyo-ku, Kyoto Dai Nippon Screen Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A method of displaying on a display means a plurality of image areas in which uniform colors are represented by a plurality of printing color components, comprising: (A) each of the plurality of printing color components. With respect to the plurality of image areas, the step of generating density order data indicating the order of the density values of the plurality of image areas; A step of sequentially selecting a plurality of image areas and overwriting image data representing the density value of each pixel in the selected image areas in the first frame memory; and (C) in the first frame memory. Converting the plurality of printing color components of the stored image data into a plurality of display color components and storing the plurality of display color components in a second frame memory; and (D) image data stored in the second frame memory. Obey And displaying the image on the display means. 2. The method for displaying a print image according to claim 1, further comprising the step of (E) changing one of the plurality of image areas, and (F) a printing color component of the changed image area. Updating the density sequence data according to the density value of (1), (G) clearing the image data of the pixels in the range before the change of the image area to be changed from the first frame memory, (H) ) Image areas having at least the ranks after the changed image area are sequentially selected according to the density order data, and at least for each pixel in the range of the changed image area, the density values of a plurality of printing color components are set. A step of overwriting the respective image data represented in the first frame memory; and (I) the image data stored in the first frame memory for at least each pixel within the range of the changed image area. A plurality of printing color components of the image data are converted into a plurality of display color components and overwritten in the second frame memory, and (J) an image is displayed on the display means according to the image data stored in the second frame memory. And a step of re-displaying the print image.