JPH09218945A - Method and device for processing image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide method and device for processing image with which image data can be reduced without omitting any pixel data of maximum density. SOLUTION: When the reduction scale of image data is instructed, corresponding to that instructed reduction scale, the number of reference picture elements in main scanning direction is decided (S1), the picture element of maximum density is found out of these decided picture elements (S2), and image data replacing the prescribed number of picture elements with that picture elements are prepared (S3). Since the pixel data are thinned out corresponding to that instructed reduction scale while using these prepared image data, the image data reduced to the instructed reduction scale can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and apparatus for inputting image data and performing scaling.

[0002]

2. Description of the Related Art An apparatus for converting an image signal into a digital signal and processing it, such as a digital copying machine, a facsimile, a scanner, etc., has a scaling function for scaling the size of image data. As an example thereof, a scaling process in a conventional digital copying machine will be described with reference to FIG.

FIG. 13A is a diagram showing an example of scaling processing in the main scanning direction, and shows a case of reduction to 2/3 (about 66.6%). In this example, the first pixel is left as it is, and the average of the second and third pixels is calculated to obtain a new second pixel. Then leave the 4th pixel as is,
Next, the average of the 5th and 6th pixels is obtained and is newly set as the 4th pixel. In this way, by repeating such reduction processing while referring to pixels adjacent in the horizontal direction, the amount of image data is reduced to 2/3 as a whole, and reduction processing of 2/3 times is realized. It Further, when the reduction processing is performed at another magnification, the pixels adjacent to each other in the left-right direction may be weighted and processed.

As shown in FIG. 13B, the line sensor 120 sets the reading direction to the main scanning direction, and the sensor 120 moves in the sub scanning direction relative to the original image at a speed v for reading. When a one-to-one image is obtained by this, consider a case where this original image is subjected to a scaling process in the sub-scanning direction. In this case, the relative speed in the sub-scanning direction is multiplied by 3/2 and the reading is performed to obtain 2/2 in the sub-scanning direction.
A reduction processing of 3 times is realized.

[0005]

However, FIG.
In the case of performing the reduction processing as shown in (A), when the reduction rate for reducing in the main scanning direction becomes 1/2 (50%) or more, some pixels are thinned out completely, and thus the reduction is performed. The image may change significantly from the image before processing. For example, in the case of reducing to 1/4 (25%) in the main scanning direction, as shown in FIG. 14, if one pixel is taken out every four pixels and reduced to 1/4, it is as shown by 130 and 131 in FIG. Black areas (which generally appear as fine lines in the image) can disappear completely.
That is, when reducing to 25%, only one pixel out of four pixels is used, and continuous pixel data of three pixels or less may be completely erased. This tendency becomes stronger as the reduction ratio becomes larger. As a method of solving such a problem, some reduction processing methods have been proposed in which the number of pixels to be referred to is increased and the calculation method is devised, but there is a drawback that the circuit becomes complicated and large-scale. It was

Further, when the reduction in the sub-scanning direction is performed by the method as shown in FIG. 13B, the reduction rate is 50% or 25%.
%, 20%, 10%, the relative scanning speed in the sub-scanning direction must be increased to 2, 4, 5, 10 times. That is, since the variable range of the scanning speed in the sub-scanning direction with respect to the original image must be extremely widened, the motor and drive mechanism used for scanning in the sub-scanning direction must be designed with a large margin. This has a problem that the device becomes large-scale and the cost becomes high. There is also a method of performing reduction processing by referring to a plurality of lines when reducing in the sub-scanning direction. In such a method, an image memory for storing image data for a plurality of lines or image data for one page is used. A page memory or the like for storing the data is required, which increases the cost of the device.

In particular, in a multifunctional machine in which a digital copying machine and a facsimile machine are combined, the market of which has been expanding in recent years, the image reading resolution is as high as 400 dpi (dots / inch) or 600 dpi. Since the resolution is reduced to about 100 dpi when transmitting a facsimile signal, the reduction rate for reducing the image data is extremely large, such as 1/4 and 1/6. Therefore, the solution of the above problems is becoming more important.

The present invention has been made in view of the above conventional example, and an object of the present invention is to provide an image processing method and apparatus capable of reducing image data without missing pixel data of maximum density. To do.

Another object of the present invention is to provide an image processing method and apparatus capable of reducing image data in the sub-scanning direction without significantly increasing the image memory.

Another object of the present invention is to provide an image processing method and apparatus capable of compressing image data without missing fine lines or the like in the image data.

Another object of the present invention is to refer to image data of a plurality of lines in the sub-scanning direction, to refer to pixels at the same position in each line, and to determine the larger or smaller pixel data, or the pixel data thereof. An object of the present invention is to provide an image processing method and apparatus capable of performing variable magnification processing with a large reduction ratio with a simple configuration by creating effective data for one line from the average value.

[0012]

In order to achieve the above object, an image processing apparatus according to the present invention has the following arrangement.
That is, an image processing apparatus for inputting image data to change the magnification, and extracting means for extracting a predetermined number of pixels of the input image data in accordance with an instructed magnification change, and a predetermined number extracted by the extracting means. Pixel extraction means for obtaining a representative pixel on the basis of the pixels, replacement means for creating image data in which the predetermined number of pixels are replaced using the pixels extracted by the pixel extraction means, and replacement of the pixels by the replacement means And a scaling means for performing scaling processing on the image data subjected to

In order to achieve the above object, the image processing method of the present invention comprises the following steps. That is, an image processing method of inputting image data and performing scaling, a step of extracting and storing the pixels of the input image data in line units, and a step of comparing the pixel data for each stored line, Based on the comparison result, a step of forming 1-line image data in which a pixel of maximum density is extracted from pixels located at the same pixel in a predetermined number of consecutive lines in accordance with an instructed scaling factor, and the formation thereof is performed. And a step of performing a scaling process on the one line data. In order to achieve the above object, the image processing method of the present invention includes the following steps. That is, an image processing method of inputting image data and performing scaling, a step of extracting and storing the pixels of the input image data in line units, and a step of comparing the pixel data for each stored line, Based on the comparison result, a step of forming 1-line image data in which a pixel of the minimum density is extracted from the pixels located at the same pixel in a predetermined number of consecutive lines according to the instructed scaling ratio. And a step of performing a scaling process on the 1-line data.

[0014]

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

[First Embodiment] FIG. 1 is a sectional view showing a schematic structure of a copying machine according to a first embodiment of the present invention.

In FIG. 1, 100 is a scanner unit and 10
Reference numeral 00 indicates a printer unit. The image of the original 2 placed on the original glass table 1 is illuminated by an exposure lamp 4 having a fluorescent lamp, a halogen lamp, or the like, and the reflected light from the original is reflected by a reflecting mirror 3 and a reduction lens 5 is formed. Is incident on. The reduction lens 5 optically reduces the input light and outputs it to a line sensor 6 such as a CCD. The line sensor 6 causes a main scanning direction (vertical direction in FIG. 1).
Image data for one line is captured. The image signal for one line thus converted into an electric signal by the line sensor 6 is output to the control unit 1001 of the printer unit 1000 at the subsequent stage. The unit A including the exposure lamp 4 and the reflection mirror scans the document 2 in the sub-scanning direction (left-right direction in FIG. 1) by moving at a speed v in the direction of arrow B, and thus the entire surface of the document 2 is scanned. Images can be captured. An operation panel 1012 includes various keys operated by an operator and a display panel.

Next, the structure of the printer section 1000 will be described.

Reference numeral 1000 denotes a printer section of the copying machine of this embodiment, which forms an image on a corresponding recording sheet according to an image signal from the scanner section 100. Reference numeral 1001 denotes a printer control unit that controls the entire copying machine of this embodiment and processes an image signal from the scanner unit 100. The printer control unit 1001 performs image processing on the input image signal, converts the image signal into a video signal, and outputs the video signal to the laser driver 1002.

The laser driver 1002 is a semiconductor laser 1
This is a circuit for driving 003, and switches the semiconductor laser 1003 on / off according to the input video signal. A laser beam 1004 emitted from a semiconductor laser 1003 is swung in the left-right direction by a rotating polygon mirror 1005 to scan an electrostatic drum 1006. As a result, an electrostatic latent image of a character pattern is formed on the electrostatic drum 1006. This latent image is developed by a developing unit 1007 around the electrostatic drum 1006 and then transferred to a recording sheet.
A cut sheet is used as the recording paper, and the cassette recording paper is stored in a paper cassette mounted in the printer unit 1000, and the paper feed roller 1009 and the transport rollers 1010 and 10 are used.
It is taken into the printer unit 1000 by the rotation of 11, and is supplied to the position of the electrostatic drum 1006.

FIG. 2 is a block diagram mainly showing the configuration of the printer control unit 1001 of the copying machine of this embodiment.

The CCD line sensor 6 converts an image signal represented by the intensity of light into an electric signal (analog signal), and the converted electric signal is converted into a digital signal by an A / D converter 7. To be done. Then, the shading correction block 8 corrects the light amount distribution characteristic of the exposure lamp 4 and the variation in the sensitivity of the line sensor 6 for each pixel. The data thus shading-corrected is input to the scaling preprocessing unit 9. A control unit 12 instructs the scaling preprocessing unit 9 and the scaling unit 10 according to the instructed scaling ratio.

Next, the operation of the scaling preprocessing unit 9 will be described with reference to FIG. 3 by taking the case of 1/4 (25%) reduction as an example.

Four pixels from the first pixel to the fourth pixel of the input image data (2,5,1,3: these numbers indicate image densities) are sequentially compared to obtain the maximum density value. The pixel value (5) is continuously output for the next four pixels. While this output is being performed, the same processing is performed on the next four pixels (6, 2, 5, 7). The reduced data in FIG. 3 is the result of 25% reduction (taking out one pixel for every four pixels) in the scaling unit 10 for the data obtained by repeating such operations. By using such a method, the problems described in the above-mentioned conventional example are improved as shown in FIG.

That is, the scaling preprocessing unit 9 takes out the pixel having the maximum density from the predetermined number of pixels, sets all of the predetermined number of pixels as the pixels of the maximum density, and thereafter, in units of the predetermined number of pixels. Due to the reduction, even if the data has only two or three consecutive pixels, if the density value is the maximum, the scaling unit 10 sets the density value to 1 with the density value held.
/ (Predetermined number) times reduction processing is performed, so for example 1 /
Even if the 4 times reduction processing is performed, if a pixel having 2 or 3 consecutive pixels has the maximum density in the unit of the pixel, these consecutive pixels will always remain. .

FIG. 5 shows the scaling preprocessing unit 9 of the first embodiment.
3 is a flowchart for explaining a scaling process in a scaling unit 10.

First, in step S1, the scaling information is input from the control unit 12, and the number of pixels to be referred to according to the scaling ratio instructed by the scaling information (4 pixels in the case of the 1/4 reduction described above). To decide. Next, in step S2, the pixels in the main scanning direction are examined in the unit of the number of pixels determined in step S1, and the pixel having the highest density is extracted. Then, in step S3, all of the predetermined pixels are replaced with the pixels extracted in step S2. Then, the process proceeds to step S4, and the scaling unit 10 thins out pixels according to the instructed scaling ratio.

By carrying out such a processing, it is possible to prevent successive pixels having a large density value from being simply thinned out by the image reduction processing, and a small image such as a thin line disappears. Can be prevented.

In the first embodiment, the pixel data having the largest density value is output in the preprocessing before scaling, but the pixel data having the smallest density value is output depending on the nature of the image. Alternatively, the average data of a plurality of pixels may be output.

Further, by changing the number of pixels per block (the above-mentioned predetermined number of pixels) corresponding to the reduction rate as shown in FIG. 6, it is possible to cope with various reduction rates.

After the reduction processing is performed by the scaling unit 10 in this way, the other image processing unit 11 performs filter processing such as edge enhancement and other image editing processing, and outputs the processed data.

[Second Embodiment] Next, a second embodiment of the present invention will be described. The schematic configuration of the image reading unit and the configuration of the image processing unit in the second embodiment are the same as those in the first embodiment described above. The effective image data for one line is created. Here, the operation of the magnification varying unit 10 will be described by taking as an example the operation of creating image data for one line from image data for four lines.

FIG. 7 is a block diagram showing the internal structure of the variable power unit 10 of the second embodiment.

The scaling unit 10 includes a reduction processing unit 20 for performing image reduction processing, a size comparison circuit 21, and a data selector 2.
2, 23, 26, and image memory (line memory) 2
It is equipped with 4 (M1) and 25 (M2). Here, the image memories 24 and 25 have a capacity for storing image data for one line, and perform processing while alternately switching the read operation and the write operation for each line.

FIG. 8 is a diagram for explaining the input operation of the first line data, and shows the data flow when the data selectors 22, 23, 26 are switched. still,
Only necessary functions are shown in FIGS. 8 to 11 below.

In FIG. 8, the input image data is reduced in the main scanning direction by the reduction processing section 20 and stored in the image memory 25 (M2). At this time, the image memory (M
1) 24 outputs valid data as a result of the processing of the image data for four lines before that.

FIG. 9 is a diagram showing a state at the time of inputting the second line data. The image data reduced by the reduction processing section 20 and the image memory (M2) as shown in FIG.
The image data of the first line data stored in 25 is compared by the comparator 21, and the larger data is stored in the image memory (M1) 24.

FIG. 10 is a diagram showing a state at the time of inputting the third line data. The image data reduced by the reduction processing section 20 and the image data stored in the image memory (M1) 24 are shown. The comparator 21 compares and stores the larger image data in the image memory (M2) 25.

FIG. 11 further shows a state at the time of inputting the fourth line data, showing the image data reduced by the reduction processing section 20 and the image data stored in the image memory (M2) 25. Are compared by the comparator 21, and the larger image data is stored in the image memory (M1) 24. Then, in the fifth line data, the connection is again made as shown in FIG. 8, and the image data stored in the image memory (M1) 24 is output as the effective image data. At the same time, the reduced image data of the next line is stored in the image memory (M2) 25. After that, by repeating the same operation, only one line of valid image data is output for every four lines, and the reduction processing of 1/4 can be performed.

Next, referring to FIGS. 12 (A) to 12 (E),
The processing operation according to the second embodiment will be described along the flow of pixel data.

FIG. 12A shows the operation of the first line data, which is the first line data (3,5,1,3,7,7) of the image data reduced by the reduction processing section 20. 5 is,
It is stored in the image memory (M2) 25. At this time, from the image memory (M1), 1 /
4, the effective image data compressed is output.

FIG. 12B shows the operation of the second line data, and the second line data (1,3,3,1,1,5, ...) Reduced by the reduction processing unit 20. ) And the first line data (3,5,1,3,7,5, ...) stored in the image memory (M2) 25 at the same position are compared by the comparator 21. As a result, the larger pixel data (3,5,3,3,7,5, ...) Is output from the comparator 21 and stored in the image memory (M1) 24.

FIG. 12C shows the processing of the third line data. Here, the third line data (2,2,6,4,2,2) reduced by the reduction processing unit 20 is used. , ...) and the second line data (3,5,3,3,7,5, ...) Stored in the image memory (M1) 24, the pixels at the same position are compared by the comparator 21. Are compared, the pixel having the larger density value is selected, and the result (3, 5, 6, 4, 7, 5, ...) Is stored in the image memory (M2) 25.

Further, as shown in FIG. 12D, in the fourth line data, the fourth image data (4,6,10,2,2,8) reduced by the reduction processing section 20 is processed. , ...) and the third line data (3,5,6,4,7,5, ...) Stored in the image memory (M2) 25, the pixels at the same position are compared by the comparator 21. The larger value (4,6,10,4,7,8, ...) output from the comparator 21 is compared with the image memory (M
1) Store in 24.

In the fifth line data processing, as shown in FIG.
2 (E), the fourth line data stored in the image memory (M1) 24 is output as an effective image. At this time, the image memory (M2) 25 is stored in FIG.
Similar to the case of the first line data shown in (A),
The image data reduced by the reduction processing unit 20 is stored as it is.

By repeating the above processing, it is possible to create effective image data for one line for every four lines and to create image data reduced to 1/4 in the sub-scanning direction.

By carrying out such processing, it is possible to carry out the reduction processing of (1 / integer) times in the sub-scanning direction without changing the scanning speed v of the lamp unit A in the sub-scanning direction. Also, by changing the number of lines to be referred to, reduction processing at other reduction ratios can be performed. Furthermore, if the above processing and the changing of the scanning speed v are combined, it is possible to carry out the reduction processing at a finer reduction ratio.

In the second embodiment, when the line data are compared with each other, the pixels at the same position are compared with each other and the pixel having the larger density data is set as the effective pixel. The present invention is not limited to this, and the pixel having the minimum density data may be made effective according to the property of the image data, or the average of the data of the pixels at the same position can be made the effective data. is there.

Even when the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), a device including one device (for example, a copying machine, a facsimile device, etc.) ) May be applied.

Further, an object of the present invention is to supply a system or apparatus with a storage medium recording a program code of software for realizing the functions of the above-mentioned embodiment,
Computer (or CP) of the system or device
U or MPU) reads and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the function 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.

Moreover, not only the functions of the above-described embodiments are realized by executing the program code read by the computer, but also the OS (operating system) running on the computer is executed based on the instructions of the program code. This also includes the case where the system) performs some 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 in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, based on the instruction of the program code, This also includes a case where a CPU or the like included in the function expansion board or the function expansion unit performs some or all of the actual processing and the processing realizes the functions of the above-described embodiments.

As described above, this embodiment has the following effects. (1) It is possible to prevent an image such as a thin line from disappearing during the reduction processing in the main scanning direction, however small the magnification is. (2) During the reduction processing in the sub-scanning direction, the variable range of the drive speed of the exposure scanning system can be narrowed even if the range of the reduction ratio is wide. Therefore, an image processing apparatus having a simple configuration and a large reduction range can be provided. realizable.

[0055]

As described above, according to the present invention, it is possible to reduce the image data without missing the pixel data having the maximum density.

Further, according to the present invention, there is an effect that the image data in the sub-scanning direction can be reduced without significantly increasing the image memory.

Further, according to the present invention, the image data can be compressed without missing fine lines or the like in the image data.

According to the present invention, with respect to the sub-scanning direction, the image data of a plurality of lines are referred to, the pixels at the same position in each line are referred to, and the larger or smaller pixel data or their By creating valid data for one line from the average value, there is an effect that it is possible to perform a scaling process with a large reduction rate with a simple configuration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a copying machine according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a printer control unit of the printer unit according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating reduction preprocessing for pixels in the main scanning direction of image data according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a scaling (reduction) process according to the first embodiment.

FIG. 5 is a flowchart showing a scaling pre-process and a scaling process according to the first embodiment.

FIG. 6 is a diagram showing an example in which the number of constituent pixels of a block is changed according to the reduction ratio in the present embodiment.

FIG. 7 is a block diagram showing a configuration of a scaling preprocessing unit according to a second embodiment of the present invention.

FIG. 8 is a diagram showing the flow of image data when reduction processing in the sub-scanning direction is performed in the second embodiment of the present invention, showing the processing of the first line.

FIG. 9 is a diagram showing the flow of image data when reduction processing in the sub-scanning direction is performed in the second embodiment of the present invention, showing the processing of the second line.

FIG. 10 is a diagram showing the flow of image data when reduction processing in the sub-scanning direction is performed in the second embodiment of the present invention, showing the processing of the third line.

FIG. 11 is a diagram showing the flow of image data when reduction processing in the sub-scanning direction is performed in the second embodiment of the present invention, showing the processing of the fourth line.

FIG. 12 is a diagram for explaining the second embodiment of the present invention by using a specific example.

13A and 13B are diagrams illustrating a conventional reduction process, FIG. 13A shows an example of pixel reduction in the main scanning direction, and FIG. 13B shows an example of pixel reduction in the sub-scanning direction.

FIG. 14 is a diagram illustrating a problem of conventional reduction processing.

[Explanation of symbols]

 1 Original Plate Glass 2 Original 4 Exposure Lamp 5 Reduction Lens 6 CCD (Line Sensor) 8 Shading Correction Section 9 Magnification Preprocessing Section 10 Magnification Processing Section 12 Control Section 20 Reduction Processing Section 21 Comparator 22.23.26 Selector 24 , 25 line memory 100 reader unit 1000 printer unit 1001 printer control unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Norimasa Iseki, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor, Tetsuya Morita, 3-30-2 Shimomaruko, Ota-ku, Tokyo Non-Incorporated (72) Inventor Hiroaki Takeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiro Kurahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (13)

[Claims] 1. An image processing apparatus for inputting image data and scaling the image data, comprising: extracting means for extracting a predetermined number of pixels of the input image data in accordance with an instructed scaling ratio; and extracting means by the extracting means. A pixel extraction unit that obtains a representative pixel based on a predetermined number of pixels, a replacement unit that creates image data that replaces the predetermined number of pixels using the pixels extracted by the pixel extraction unit, and the replacement unit. An image processing apparatus comprising: a scaling unit that performs scaling processing on image data in which pixels have been replaced. 2. The image processing apparatus according to claim 1, wherein the pixel extraction unit sets a pixel having the maximum density among the predetermined number of pixels as a representative pixel. 3. The image processing apparatus according to claim 1, wherein the pixel extracting unit sets a pixel having the minimum density among the predetermined number of pixels as a representative pixel. 4. The image processing apparatus according to claim 1, wherein the pixel extraction unit obtains an average value of the predetermined number of pixels and sets a pixel having a density of the average value as a representative pixel. 5. An image processing apparatus for inputting image data to perform scaling, comprising line storage means for extracting and storing pixels of input image data line by line, and lines stored in the line storage means. Based on the comparison result by the pixel data for each pixel and the comparison result by the comparison device, the pixel having the maximum density is extracted from the pixels located at the same pixel in the continuous predetermined number of lines according to the instructed scaling factor. An image processing apparatus comprising: a data forming unit that forms the 1-line image data described above; and a scaling unit that performs a scaling process on the 1-line data formed by the data forming unit. 6. An image processing apparatus for inputting image data to perform scaling, comprising line storage means for extracting and storing pixels of input image data line by line, and lines stored in the line storage means. A comparing unit that compares pixel data for each pixel, and a pixel with the minimum density is extracted from the pixels located at the same pixel in a predetermined number of consecutive lines based on the comparison result by the comparing unit, according to the instructed scaling factor. An image processing apparatus comprising: a data forming unit that forms the 1-line image data described above; and a scaling unit that performs a scaling process on the 1-line data formed by the data forming unit. 7. The comparing means compares line data comparing at least one line of image data with each other and pixel data of one line satisfying a comparison condition among the image data compared by the line comparing means. The line memory for storing, the image data of the next line and the image data stored in the first line memory are compared by the line comparing means, and the image data of one line satisfying the comparison condition is stored in the line memory. The image processing apparatus according to claim 6, wherein the image processing apparatus stores the image in the image processing apparatus. 8. An image processing method for inputting image data to perform scaling, comprising a step of extracting a predetermined number of pixels of the input image data in accordance with an instructed scaling ratio, and a step of extracting the predetermined number of extracted pixels. A step of obtaining a representative pixel based on the pixel, a step of creating image data in which the predetermined number of pixels are replaced by using the extracted pixel, and a scaling process for the image data in which the pixel is replaced An image processing method comprising: a step of executing. 9. The image processing method according to claim 8, wherein the representative pixel is a pixel having the maximum density among the predetermined number of pixels. 10. The image processing method according to claim 8, wherein the representative pixel is a pixel having the minimum density among the predetermined number of pixels. 11. The image processing method according to claim 8, wherein the representative pixel is a pixel having a density of an average value of the predetermined number of pixels. 12. An image processing method for inputting image data and performing scaling, comprising: extracting and storing pixels of input image data line by line; and comparing pixel data for each stored line. Based on the process and the comparison result, according to the designated scaling factor,
A step of forming 1-line image data in which a pixel of maximum density is extracted from pixels located at the same pixel in a predetermined number of continuous lines, and a step of performing a scaling process on the formed 1-line data An image processing method comprising: 13. An image processing method for inputting image data and performing scaling, comprising: extracting and storing pixels of input image data line by line; and comparing pixel data for each stored line. Based on the process and the comparison result, according to the designated scaling factor,
A step of forming 1-line image data in which a pixel having the minimum density is extracted from pixels located at the same pixel in a predetermined number of continuous lines; and a step of performing a scaling process on the formed 1-line data. An image processing method comprising: