JP2942125B2 - Display method of print image - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for displaying a plurality of image areas in which uniform colors are represented by a plurality of printing color components on a display means, and more particularly to a method for displaying 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, gravure-printed figures and characters on soft packaging materials such as vinyl and cellophane have been used as food packages. In color printing, a plurality of colors are usually overprinted. However, since the soft packaging material easily expands and contracts, a so-called misregistration (misregistration between color plates) easily occurs. Therefore, a process called “negation” is performed in which adjacent image areas are overlapped by about several mm. FIG.
FIG. 4 is an explanatory diagram showing an example of performing a relief processing. 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 region Rb is painted with a color having a higher intensity than the first image region Ra. Here, the “color intensity” is, for example, in the case of the YMCK color system, an intensity defined in advance as an order such as Y <M <C <K.

In such a case, the first image area Ra is expanded as shown in FIG.
A relief region Rc that appears to sneak under b is formed. When gravure printing is performed on the soft packaging material, the width of the relief region Rc may be as large as about 3 mm, which is considerably large enough to be recognized by the naked eye. In addition,
The relief region Rc is extended based on the image region Ra, and the two regions Ra and Rc are generally represented by one graphic data as a single image region. In other words, the image of FIG. 16B has two image areas (Ra +
Rc) and Rb are represented by two graphic data respectively.

In recent years, there has been a demand for displaying an image as shown in FIG. 16 (b) on a display device such as a color CRT to determine the quality of the image. When an image in which a plurality of image areas are overlapped is displayed on a display device, a color system used for printing (for example, YMCK color system) is converted to a display color system (for example, RGB color system). There is a need. However, since the level of each component of RGB is determined by the combination of each component of YMCK, conventionally, FIG.
As shown in (1), image regions Ra, Rc, (Rb-Rc) in which at least one YMCK color component is different are obtained, and these YMCK components are converted into RGB components.

[0005]

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

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and when displaying print image areas overlapping each other on a display device, there is no need to finely separate the image areas, and It is an object of the present invention to provide a method capable of relatively faithfully reproducing colors of overlapping portions.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method of the present invention displays a plurality of image areas in which uniform colors are expressed by a plurality of printing color components. (A) generating density order data indicating an order of density values of the plurality of image areas for each of the plurality of printing color components; and (B) generating the plurality of printing color components. For each of the color components, the plurality of image areas are sequentially selected in ascending 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 converted to the first image data. (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 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.

For each color component for printing, the image data of a plurality of image areas are overwritten in the first frame memory in ascending order of the density value, so that the image data finally stored in the first frame memory is Is image data that reflects the color at the time of printing relatively faithfully. In addition, since it is only necessary to sequentially overwrite the image data of each image area, it is not necessary to separate each image area.

The method for displaying a print image according to the present invention further comprises: (E) changing one of the plurality of image areas;
(F) a step of updating the density order data in accordance with the density value of the printing color component of the image area after the change; and (G) a process of updating the image area to be changed within the range of the sum area before and after the change. Clearing the image data from the first frame memory; and (H) sequentially selecting image areas having at least the order after the changed image area according to the density order data, and at least selecting a range of the changed image area. Overwriting the first frame memory with image data respectively representing the density values of a plurality of printing color components for each of the pixels in (i), and (I) at least each pixel in the range of the image area after the change. 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 overwriting the second frame memory with (J). And a, a step of re-displaying the image on the display means in accordance with image data stored in the second frame memory.

The image data in the range of the sum area of the image areas before and after 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. Therefore, even when the image area is changed, the image can be displayed again in a relatively short time.

[0011]

FIG. 1 is a block diagram showing the configuration of an image processing system to which an embodiment of the present invention is applied. The image processing system includes a CPU 30, a ROM 32, 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 a YMCK component into an RGB component.
0, a second frame memory 42 for storing image data represented by RGB components, a display control unit 44, and a color CRT 46. The above circuits other than the color CRT 46 are connected by a CPU bus.

FIG. 2 is an explanatory diagram showing an image to be processed in this embodiment. FIG. 2A shows only the outlines of the six image regions R1 to R6. FIG.
(B) shows a dot area ratio of each color component of YMCK for each image area.

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

FIG. 4 is a flowchart showing a 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. Note that the processing in step S10 is performed in 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 flowchart showing a detailed procedure of step S10. In step S11, YMCK
The six image areas R1 to R6 are sorted in ascending order of density value for each color component. FIG. 6 shows density order data DOR representing the result of sorting the Y components in the order of density values.
FIG. 3 is an explanatory diagram showing the configuration of FIG. The density order data is composed of a header section and an address pointer section. The header section contains data indicating which of the four color components YMCK. In the address pointer section, address pointers indicating the start addresses of the image areas are registered in ascending order of the density value. As shown in FIG.
As for the components, "R1,
R2, R4, R5, R3, R6 ". Note that similar density order data DOR is created for the 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 the data indicates the order of the density values of the image area 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. I do. FIG. 7 is an explanatory diagram showing the processing content of step S12. FIG.
(A) shows six image regions R1 to R6 for the Y component.
Are shown, and this is indicated by the density order data DOR shown in FIG. FIG.
(B) shows how the graphic vector data of each image area is developed into image data according to this order, and overwritten on 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. As described above, the image data is overwritten in ascending order of the density value, so that the image region with the low density value is hidden by the image region with the high density value and becomes invisible. The image finally obtained in this manner shows the same state as that actually printed.

The processing in 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, 38K.

As shown in FIG. 7, if the image data is overwritten in ascending order of density, the conventional FIG.
There is an advantage that it is not necessary to perform the process of dividing the image area as shown in FIG.

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

FIG. 8 is a block diagram showing the internal configuration 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 operation circuit 60. The color conversion operation circuit 60 includes four lookup tables 61 to 64 and three adders 65, 66, 67.

The color conversion operation 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 an RGB component (hereinafter simply referred to as “RGB data”). This is a circuit that performs an operation to convert the Lookup tables 61-
Reference numeral 64 outputs RGB data values 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 are provided in each of the lookup tables 61 to
Add the B component of the RGB data output from 64,
B component of output data (= fYB (Y) + fMB (M) + fCB
(C) + fKB (K)). Although only three adders 65 to 67 for the B component are shown in FIG. 8 for convenience of illustration, actually, three identical adders are provided for the G component and the R component, respectively. ing.

The RGB data obtained by the color conversion operation circuit 60 is input to the color conversion table 50 and
The signal is input to the R circuit 52. The OR circuit 52 outputs the logical sum of the output of the color conversion table 50 and the output of the color conversion operation circuit 60. As will be described later, since only one of the color conversion table 50 and the color conversion operation 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 look-up table for inputting YMCK data and outputting 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 data area of 0, 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 the RGB data corresponding to the YMCK data has been registered. In other words, the color conversion operation circuit 60 performs the operation once, the registration flag F is set to 1 for the YMCK data in which the RGB data is registered in the color conversion table 50, and the operation is executed once by the color conversion operation circuit 60. The registration flag F is set to 0 for the YMCK data that has not been set.
Is set to

It should be noted that, as a data area of the color conversion table 50, only data relating to a combination of YMCK data once calculated is added without previously securing areas corresponding to all combinations of four YMCK data values. You may make it go.

FIGS. 10 and 11 are explanatory diagrams for explaining the functions of the color conversion circuit 40. FIG. FIG. 10 shows the input Y
The case where the registration flag F for the MCK data is 1 is shown. As shown in FIG. 10, the first frame memory 38
The YMCK component is read out from Y, 38M, 38C, 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 the second frame memories 42R, 42G, and 42B and written. 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 calculates the RGB data, and stores the obtained RGB data in the second frame memory 42.
R, 42G, and 42B are written and 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
YMCK data read from the color conversion table 50
Is input to If the registration flag F for the input YMCK data is 1 (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 a signal of the registration flag F to the four lookup tables 61 to 64. The look-up tables 61 to 64 are disabled when the registration flag F is 1, and are enabled when the registration flag F is 0. Therefore, only when the registration flag F is 0 (unregistered), data is output from the lookup tables 61 to 64, respectively.
For example, for the B component, the lookup table 61
FYB (Y), fMB (M), fCB
(C) and fKB (K) are output, and these are added by three adders 65 to 67, and the B component (=
fYB (Y) + fMB (M) + fCB (C) + fKB (K)) is obtained. The RGB data thus obtained is provided 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.

It should be noted that the color conversion method in the color conversion operation circuit 60 can employ various methods other than those described above. In particular, when a complicated operation such as an interpolation operation is performed by the color conversion operation circuit 60, the use of the color conversion table 50 having the registration flag F as shown in FIG. Become noticeable. The color conversion process is performed by executing a software program on the CPU 3.
It can also be realized by executing 0.

As described above, step S13 (FIG. 5)
When the color conversion in is completed, step S20 (FIG. 4)
The image is displayed on the color CRT 46 in accordance with the image data in the second frame memory 42.

In step S30, the operator observes the displayed image and changes the image if necessary. Changing the image includes correcting the shape of the image area, correcting the color in the image area, deleting the image area, and creating a new image area.

FIG. 12 is a flowchart showing a detailed procedure of step S30. In step S31, the operator instructs an image change while watching the color CRT 46. The CPU 30 changes the graphic vector data (FIG. 3) of the image area to be changed according to this instruction.
Hereinafter, the processing contents of step S30 will be sequentially described for three cases of correction of an image area, deletion of an image area, and creation of a new image area.

FIG. 13 is an explanatory diagram showing the processing content of step S30 when the image area is corrected. FIG.
(A) shows a state in which the image area R1 is enlarged rightward in step S31, and an instruction to correct the image area R1a is indicated by a broken line.

Steps S32 to S37 are processing automatically executed under the control of the CPU 30. First, in step S32, the image area to be changed is reflected in the density order data DOR (FIG. 6). FIG. 13B shows the 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 an intermediate position 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 region before and after the change” means both the image region R1 before the change and the image region R1a after the change.

When the shape and color of the image area are corrected, both the image area before the change and the image area after the change exist, but in the case of deleting the image area, the image area after the change is not exist. Also, 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, the sum area R
Image regions R2 and R3 have been searched as other image regions at least partially overlapping 1a. Step S
At 33, vector data representing the shape of the overlap portion OL (the shaded area in the figure) between the image area before and after the change and another image area is also created.

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

In step S34, the YMCK data for each pixel in 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 and other image areas. For all the pixels included in the sum area, the YMC
K data is cleared.

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

In step S36, the YM for each pixel in the overlapping portion OL between the image area before and after the change and the other image area is determined.
The CK data is overwritten on the first frame memory 38. At this time, according to the order shown in the concentration order data,
Y of the image area having a higher rank than the image area R1a after the change
Only MCK data is overwritten. In the example of FIG. 13B, the image areas R4 and R, which have a higher rank than the image area R1.
5, R3, and R6 are overwritten with the YMCK data of the overlapping portion OL. FIG. 13D shows the YM of the image area R1a after the correction in steps S35 and S36,
This shows a state in which the CK data has been overwritten.

As described above, when the image area is corrected, the YMCK data is updated only for the image area before and after the change and for the overlapping part of the image area before the change and another image area. The processing time for updating data can be reduced.

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

The update processing of the YMCK data and the RGB data for the overlapping part OL (steps S36, S3
Step 7) may be performed not only for the pixels within the range of the overlapping portion OL, but also for each pixel in the rectangular region circumscribing the overlapping portion OL2.

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

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

FIG. 14 is an explanatory diagram showing the processing content of step S30 when deleting an image area. FIG.
(A) indicates that the image area R1 should be deleted in step S31. Note that when deleting an image area, 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 order 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 overlapping the image area R1 before the change (FIG. 14C). In step S33, vector data representing the overlapping portion OL1 of the image regions 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 image area after the change does not exist, step S
Nothing is done in 35. In step S36, the YMCK data for each pixel within the range of the overlapping portion OL1 is
First frame memory 3 according to density order data DOR
8 is overwritten (FIG. 13D). Then, in step S37, the YMCK data for each pixel within the range of the image area before and after the change is color-converted into RGB data, and the obtained RGB data is overwritten on 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. FIG. 15 (b)
Indicates that the density of the Y component in the image region R7 is
When the density is in the middle of the density of the Y component of No. 5, the address pointer of the image area R7 is arranged between the address pointers of the image areas R4 and R5 in the density order data DOR.

In step S33, the changed image area R
7 is searched for, and the overlapping portion O
L2 vector data is obtained. In step S34, the YMCK data for each pixel within the range of the changed image area R7 is cleared. In step S35,
The YMCK data for each pixel in the changed image area R7 is written to 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 overlapping portion OL2 is converted into the density order data DO.
R is overwritten in the second frame memory 42 in the order shown in FIG. 15 (b). For example, as for the Y component, the Y of the overlapping portion OL2 in the image regions R5, R3, and R6 having the order after the new image region R7.
MCK data is overwritten in this order. in this way,
If the YMCK data is overwritten only for the image area of the order after the new image area R7, the processing time required for redisplaying the corrected image can be reduced. FIG. 15D shows steps S35 and S35.
36 shows how the YMCK data is changed for the new image area R7 and the overlapping part OL2.

In step S37, a new image area R7
The YMCK data is converted into RGB data and written to the second frame memory 42 for each of the pixels in the.

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

As described above, in the above embodiment, when an image change (modification, deletion, new creation of an image area) is instructed by the operator, the color data of the image area before and after the change and the image area before and after the change are changed. 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 redisplayed at a high speed. These advantages are:
In step S10, the YMCK data of the image area is overwritten in order of density for each color component without separating the image areas overlapping each other.

The present invention is not limited to the above embodiment, but can be implemented in various modes without departing from the gist of the invention. For example, the following modifications are possible.

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

(2) In the above embodiment, the shape of the image area is drawn with a geometric shape. However, 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, even when the print image areas overlapping each other are displayed on the display means, it is not necessary to finely separate the image areas and the image areas overlap each other. The effect is that the color of the portion can be reproduced relatively faithfully.

According to the second aspect of the present invention,
There is the effect that the image can be redisplayed in a relatively short time even if the image area is changed.

[Brief description of the 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 to be processed in the embodiment.

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

FIG. 4 is a flowchart illustrating a processing procedure according to the embodiment;

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

FIG. 6 is an explanatory diagram showing a configuration 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.

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

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

FIG. 11 is an explanatory diagram illustrating functions of a 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 correcting an image area.

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

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

FIG. 16 is an explanatory diagram showing a conventional example of performing a relief process.

[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 controller 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

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI G06T 1/00 G06F 15/62 310A H04N 1/46 H04N 1/46 Z (72) Inventor Naoto Nozawa Horikawa Toji, Kamigyo-ku, Kyoto-shi 4-Chome Ten-no-Cho, No. 1 1 at Kitakita-cho Dainippon Screen Mfg. Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) G09G 5/02 G03F 1/00 G03F 3/10 G06T 1 / 00 H04N 1/46

Claims (2)

(57) [Claims] 1. A method for displaying on a display means a plurality of image areas in which respective uniform colors are represented by a plurality of printing color components, wherein (A) each of the plurality of printing color components Generating density order data indicating the order of the density values of the plurality of image areas; and (B) for each of the plurality of printing color components, in ascending order of the density values indicated by the density order data. A step of sequentially selecting a plurality of image areas and overwriting image data representing a density value of each pixel in the selected image area 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 them in a second frame memory; and (D) storing the image data stored in the second frame memory. Obey Displaying the image on the display means by using the display method. 2. The method for displaying a print image according to claim 1, further comprising: (E) changing one of the plurality of image areas; and (F) printing color components of the changed image area. (G) clearing image data of pixels within the range of the sum area before and after the change of the image area to be changed from the first frame memory; and (H) sequentially selecting image areas having at least the order after the changed image area in accordance with the density order data, and at least for each pixel within the changed image area, a plurality of printing color components Overwriting the first frame memory with the image data each representing the density value; and (I) storing in the first frame memory at least each pixel within the range of the changed image area. Converting a plurality of printing color components of the obtained image data into a plurality of display color components and overwriting the second frame memory, and (J) displaying the image data in accordance with the image data stored in the second frame memory. Redisplaying the image on the means.