JP2000152003A - Image processor and image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor capable of recording image information satisfactorily in both resolution and gradation properties and effectively suppressing the occurrence of a pseudo outline, etc., by means of the simple control by controlling the multilevel pseudo halftone processing result in dots and varying the recording dot array position. SOLUTION: The multilevel pseudo halftone processing result is controlled in dots and the receding dot array position is varied. A pseudo halftone processing part 106 of this image processing device applies the pseudo halftone processing to the multilevel image signals having density of 400 DPI in the horizontal scanning direction and 600 DPI in the vertical scanning direction and preprocessed at a preprocessing part 102 to convert the image signals into quadruple signals. Then the quadruple signals are sent to a dot control part 114 which converts these signals into a binary recording dot array that can be stably recorded in response to the resolution. A recorder 104 forms and prints out an image corresponding to the recording signal receive from a selector 105 with recording density of 600 DPI in the horizontal scanning direction and 1200 DPI in the vertical scanning direction respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an information processing apparatus and method for processing and outputting image information.

[0002]

2. Description of the Related Art A multi-value recording method based on an error diffusion method is known as a technique for generating a high-quality recording signal for multi-value recording in a conventional copying machine, facsimile, printer, or the like. It is known that this type of conventional method can express both sharpness and gradation in an image in which a halftone and a thin character line are mixed.

For example, by setting the recording dot density to 600 DPI or more, the sharpness of characters is improved, and the granularity of the dots in the halftone portion is reduced.

[0004]

However, when a halftone portion is recorded and expressed in accordance with a conventional method, particularly a halftone portion according to a multi-valued pseudo halftone process of numerical values, a pseudo contour may occur at a specific density. . For this reason, deterioration of the image quality in the halftone area has been unavoidable.

[0005]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above problems, and has, for example, the following arrangement as one means for achieving the above object.

That is, processing means for performing multi-value pseudo halftone processing on image information, developing means for developing the processing information by the processing means into a dot pattern, and developing pixel positions developed by the developing means in the sub-scanning direction. The image processing apparatus is characterized by comprising a variation unit that varies according to the coordinate position, and an output unit that displays and outputs the developed pixel.

[0007] For example, the expanding means includes converting means for converting the processing information by the processing means into a plurality of types of binary signals, and the changing means comprises a plurality of types of binary signals converted by the converting means. The developing pixel position is varied by selecting one type of binary signal for each pixel corresponding to the coordinate position in the sub-scanning direction from the above.

Also, for example, the variation means varies the development pixel position developed by the development means together with the coordinate position in the sub-scanning direction in accordance with processing information from the processing means. .

Further, for example, a random number generating means for generating a random number for each pixel is further provided, and the changing means further changes a developed pixel position according to a random number value generated by the random number generating means. .

A generating means for generating a random number for each pixel of the image information; a processing means for performing a multi-value pseudo halftone processing on the image information; and a developing means for developing the processing information by the processing means into a dot pattern. Output means for displaying and outputting the dot pattern developed by the developing means, wherein the processing means performs multi-value pseudo halftone processing on the image signal by an error diffusion method, and determines an allocation ratio to peripheral pixels by the error diffusion method. The switching is performed according to a random number value generated by the generating means.

For example, the distribution ratio to the peripheral pixels can be changed by setting a plurality of types of error diffusion matrices in advance and switching one of the set matrices according to a random value generated by the generating means. It is characterized by performing.

Further, for example, the output means is a printing means for permanently displaying image information.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment] Hereinafter, a first embodiment of the present invention in which the present invention is applied to a copying machine will be described in detail.

(Main Body Configuration) FIG. 1 is a schematic sectional view of a color copying apparatus to which an embodiment of the present invention is applied. The example shown in FIG. 1 has a digital color image reader unit at the top and a digital color image printer unit at the bottom.

In the reader section shown in FIG. 1, an original 30 is placed on an original platen glass 31, and an optical system reading drive motor 35 is provided.
A known document scanning unit including the exposure lamp 32 is exposed and scanned at a constant speed determined according to a preset copy magnification. The reflected light image from the document 30 is condensed by a lens 33 onto a full color sensor (CCD) 34 to obtain a color separation image signal.

As the full-color sensor, R (red), G (green), B
A three-line CCD 34 with a (blue) filter is used. The color-separated image signal is supplied to an image processing unit 36.
The image processing is performed by the controller 37, and the image is sent to the printer.

An operation section is provided around the platen glass 31, and switches for setting various modes related to a copy sequence, a display and a display are arranged.

In the printer section of FIG. 1, a photosensitive drum 1 as an image carrier is rotatably supported in the direction of an arrow, and a pre-exposure lamp 11, a corona charger 2,
Laser exposure optical system 3, potential sensor 12, four developing units 4y, 4c, 4Bk of different colors, on-drum light amount detecting means 1
3. The transfer device 5 and the cleaning device 6 are arranged.

In the laser exposure optical system 3, an image signal from a reader section is converted into an optical signal by a laser output section (not shown), and the converted laser light is reflected by a polygon mirror 3a, and a lens 3b and a mirror 3c, and is projected on the surface of the photosensitive drum 1.

At the time of image formation in the printer section, the photosensitive drum 1 is rotated in the direction of the arrow, and the photosensitive drum 1 after having been neutralized by the pre-exposure lamp 11 is uniformly charged by the charger 2 so as to emit light for each separated color. The image E is irradiated to form a latent image.

Next, by operating a predetermined developing device, the latent image on the photosensitive drum 1 is developed, and a toner image is formed on the photosensitive drum 1 using a resin as a base material. The developing device has an eccentric cam 24.
By the operations of y, 24m, 24c, and 24Bk, the photosensitive drum 1 is selectively approached in accordance with each of the separated colors.

Further, the toner image on the photosensitive drum 1 is
The image is transferred from one of the preselected recording material cassettes 7a, b, and c to the recording material supplied to a position facing the photosensitive drum 1 via the conveyance system and the transfer device 5. The selection of the recording material cassette is performed by driving any one of the pickup rollers 27a, 27b, and 27c according to a control signal from the controller unit 37 in advance according to the size of the recording image.

In the present embodiment, the transfer device 5 includes a transfer drum 5a, a transfer charger 5b, a suction roller 5g opposed to a suction charger 5c for electrostatically sucking a recording material, an inner charger 5d, and an outer charger. A recording material carrying sheet 5f made of a dielectric is integrally stretched in a cylindrical shape in a peripheral opening area of the transfer drum 5a which is rotatably driven and has a container 5e. The recording material supporting sheet 5f uses a dielectric sheet such as a polycarbonate film.

A drum-shaped transfer device, that is, a transfer drum 5a
As the is rotated, the toner image on the photosensitive drum 1 is transferred by the transfer charger 5b onto the recording material carried on the recording material carrying sheet 5f.

As described above, a desired number of color images are transferred to the recording material sucked and conveyed to the recording material carrying sheet 5f to form a full-color image.

In the case of forming a full-color image, when the transfer of the toner images of four colors is sequentially completed in this way, the recording material is separated from the transfer drum 5a by the action of the separation claw 8a, the separation push-up, the roller 8b and the separation charger 5h. Then, the sheet is discharged to the tray 10 via the heat roller fixing device 9.

On the other hand, the post-transfer photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned by the cleaning device 6.

When images are formed on both sides of a recording material,
Immediately after the fixing device 9 is ejected, the conveyance path switching guide 19 is driven, and once guided to the reversing path 21a via the conveyance vertical path 20, the rear end of the reversing roller 21b is moved forward by the reverse rotation of the reversing roller 21b. And is retracted in the direction opposite to the direction in which the sheet is fed, and stored in the intermediate tray 22. Thereafter, an image is formed on the other surface again by the above-described image forming step.

Further, in order to prevent scattering of powder on the recording material supporting sheet 5f of the transfer drum 5a and adhesion of oil on the recording material, the fur brush 14 and the recording material supporting sheet 5f are used. 14, a backup brush 15, an oil removing roller 16, and a recording material carrying sheet 5.
Cleaning is performed by the action of the backup brush 17 facing the roller 16 via f. Such cleaning is performed before or after image formation, and when a jam (paper jam) occurs.
It is performed at any time when it occurs.

Further, in the present embodiment, the eccentric cam 25 is operated at a desired timing to transfer the transfer drum 5a.
By operating the cam follower 5i integrated with the photosensitive drum 1, the gap between the recording material carrying sheet 5a and the photosensitive drum 1 can be arbitrarily set. For example, during standby or when the power is off, the interval between the transfer drum 5a and the photosensitive drum 1 is increased.

(Configuration of Image Processing Unit) FIG. 2 shows a detailed configuration of the image processing unit 36 shown in FIG. Hereinafter, a detailed configuration of the image processing unit 36 and the controlled units around the image processing unit 36 according to the present embodiment will be described with reference to FIG. In FIG. 2, the scanner unit data image is 400 DPI in the main scanning direction and 6 in the sub-scanning direction.
The pre-processing unit 102 pre-processes the output signal of the CCD 34 read at a density of 00 DPI.

In the pre-processing by the pre-processing unit 102, an analog signal from the CCD 34 by a built-in A / D converter (not shown) is converted into a corresponding digital signal, further shading correction is performed, and luminance-density conversion is performed. I do. Further, a filtering process using a spatial filter is performed as needed.

The pseudo-halftone processing unit 106 includes a pre-processing unit 10
The multi-valued image signal pre-processed in step 2 having a density of 400 DPI in the main scanning direction and 600 DPI in the sub-scanning direction is converted into a quaternary signal by pseudo halftone processing. Pseudo halftone processing unit 10
In the halftone processing in No. 6, all halftone processing such as a generally known multi-level error diffusion method or an improved method thereof can be used, and the processing method is not limited.

In the pseudo halftone processing section 106 of the present embodiment shown in FIG. 2, since the multilevel signal from the preprocessing section 102 is converted into a quaternary signal, each pixel in the main scanning direction 400 DPI is It is converted into a quaternary image signal from 0 (white) to 3 (black).

The quaternized image signal is sent to a dot control unit 114 unique to the present embodiment, and the dot control unit 114 can perform stable printing according to the resolution of the printing apparatus 104. It is converted to a binary recording dot array.

The selector (MPX) 105 is an external recording signal 1 which is an image signal from an external device, which is not described in detail.
03 and the recording signal 109 from the dot control unit 114 are selected and supplied to the recording device 104. Selector 10
The selection switching control of No. 5 is performed by a selection signal 157 from the controller unit 37, for example.

The recording apparatus 104 of this embodiment forms an image corresponding to the recording signal from the selector 105 at a recording density of 600 DPI in the main scanning direction and 1200 DPI in the sub-scanning direction, and outputs a permanent visible display (printing). Output.

FIG. 3 is a block diagram showing a detailed configuration of the dot control unit 114 shown in FIG.

In FIG. 3, the image signal 107 quaternized by the pseudo halftone processing unit 106 is sent to the address terminal 144 of the ROM 142 and to the flip-flop 141 of the dot control unit 114. Then, the flip-flop 141 to which the image reading clock is input to the clock input terminal is delayed and held by one pixel, and the RO
It is sent to the address input terminal 144 of M142.

As a result, a quaternary signal for two pixels continuous in the main scanning direction is sent to the address input terminal of the ROM 144. Reference numeral 150 denotes a known sub-scanning direction coordinate counter (Y coordinate counter), which outputs a specific bit (1) to the dot control unit 115. This specific bit (1)
Are supplied to the remaining address input terminals 144 of the ROM 142.

The ROM 142 stores in advance an array of recording dot signals corresponding to the quaternary signal of two pixels of the quaternary signal 107, and stores the array of four dots of two pixels continuous in the main scanning direction.
00DPI quaternary signal 1200 in the main scanning direction
It can be converted to a DPI binary signal.

Therefore, the output of the ROM 142, that is, six binary recording signals 146 are sent to the shift register 143, and are temporarily held in parallel.
8 is read out in synchronization with the 1-bit raster recording signal 1
09 is output to the selector 105.

The dot control unit 1 described above and shown in FIG.
An operation timing chart of No. 14 is shown in FIG.

As shown in FIG. 4, the flip-flop 141 of the dot control unit 114 operates with an image reading clock 145.
The output (binary recording signal) 146 of the ROM 142 is held at the rising edge of the clock 147 divided by two.

FIG. 5 shows a 400D in this embodiment.
FIG. 9 is a diagram illustrating an example of specific data processing in a case where a seven-value expression is performed at a density of 200 (lines / inch) from an image signal quaternized by a pseudo halftone processing unit 106 of a PI.

In FIG. 5, a variable A is a Y coordinate counter 1
50 bits indicate that the recording signal pattern is switched every line when bit 0 is used and every 4 lines when bit 1 is used. Then, according to the combination of the respective 2n, 2n + 1th quaternary signals continuous in the main scanning direction, 1200 pixels corresponding to the sum of the respective quaternary signals are obtained.
The DPI binary recording signal is made continuous.

At this time, if the recording dot group is set so as to grow substantially symmetrically from the substantially center to the left and right according to the number,
A recording line having a density of 200 lines / inch parallel to the sub-scanning direction is formed on the recording material surface, and the line width is modulated in seven stages according to the density. This pattern disperses the smallest recording dots in the thinner parts without causing discomfort to human eyes,
In the intermediate density region, a plurality of recording dots are solidified, so that recording can be stably and faithfully performed with a density, and generation of a pseudo contour is suppressed.

Each recording pattern shown in FIG. 5 is an example, and the present embodiment is not limited to the above-described recording pattern.

As described above, according to the present embodiment, the multi-value pseudo halftone processing result is dot-controlled to change the recording dot array position, thereby satisfying both resolution and gradation. This makes it possible to efficiently perform the recording by performing simple control.

[Second Embodiment] In the above-described first embodiment, the switching of the recording pattern of the dot control section 114 is performed based on the Y coordinate value. The switching is not limited to the above example, and this switching may be performed by using a random number generated for each pixel and the Y coordinate value. A description will be given of a second embodiment according to the present invention in which the switching of the recording pattern of the dot control unit 114 is performed by using a random number generated for each pixel and a Y coordinate value.

Also in the second embodiment, the basic configuration is the same as that of the above-described first embodiment, and the following description will be made with respect to portions different from the above-described first embodiment. Detailed description of the same configuration as that of the first embodiment will be omitted.

In the second embodiment, the dot control unit 1
14 are different. FIG. 6 shows a detailed configuration of the dot control unit 14 according to the second embodiment. In the first embodiment described above, predetermined bit information from the Y coordinate counter 150 is directly input to the address input terminal 144 of the ROM 142.

However, in the second embodiment shown in FIG. 6, a random number generator 149 is provided, and a predetermined bit information from the Y coordinate counter 150 and the random number generator 149 are provided at an address input terminal 144 of the ROM 142. 149 and the logical product of the logical product circuit with the logical product circuit.

Therefore, in the second embodiment,
Image signal 107 quaternized by pseudo halftone processing section 106
Are held delayed by one pixel in the flip-flop 141, and are input to the address input terminal of the ROM 142 as quaternary signals of two pixels that are continuous in the main scanning direction, as in the first embodiment. However, a specific bit (0) of the Y-coordinate counter and a logical operation (AND) value of a random number are input to the other address input terminals.
Connected to.

That is, in the second embodiment, the recording position of the pixel of interest is changed for each line of the image signal by a random number. Further, it is possible to set every four lines or every eight lines by changing a specific bit of the Y coordinate counter.

The final seven-level recording signal 109 is not different from the specific example shown in FIG. 5 of the first embodiment. One of these recording signals is output to the recording device 104 via the selector 105. In the second embodiment, the variable A shown in FIG. 5 represents the logical sum of the specific bit of the Y coordinate value counter 150 and the random number value of the random number generator 149.

As described above, according to the second embodiment, since the recording position is changed by the Y coordinate value and the random number, the resolution and the gradation of an image having regularity such as gradation are obtained. Therefore, it is possible to perform recording that satisfies both characteristics, and it is possible to efficiently suppress the occurrence of false contours and the like by simple control.

[Third Embodiment] In the above description, the recording position was changed by the dot control unit 114. However, the present invention is not limited to the above example, and the error in the pseudo halftone processing is described. By adding a random number component to an image by switching the diffusion matrix using random numbers, recording that satisfies both resolution and gradation may be enabled to suppress the occurrence of false contours and the like. A third embodiment according to the present invention configured as described above will be described below.

In the third embodiment, the basic configuration is almost the same as that shown in FIGS. 1 and 2 shown in the first embodiment, but the dot control unit 114 is not provided. The pseudo halftone processing unit 106 is partially different. FIG. 7 shows a configuration of adding a random number component to an image by switching the error diffusion matrix by a random number in the pseudo halftone processing unit 106 of the third embodiment.

In the following description, a detailed description of the same configuration as in the first embodiment will be omitted, and different portions will be described in detail.

In the third embodiment shown in FIG.
The multi-valued image signal from the preprocessing unit 102 is input to the image signal input unit 2
Enter 01. When a pixel signal is input to the image signal input unit 201, the pixel signal is sent to the error distribution processing unit 202 as a target pixel signal 211. The error distribution processing unit 202 adds the error signal 213 from the error calculation processing unit 204 generated when the previous pixel is processed to the target pixel signal 211, and generates a corrected internal density level correction signal 212. You.

The internal density level correction signal 212 corrected by the error half processing section 202 is input to the multi-level processing section 203 and converted into a multi-level signal 212 converted to a density level corresponding to a predetermined output gradation. The image is output to the image signal output unit 105. Then, the image signal is output from the image signal output unit 205 to, for example, the selector (MPX) 105.

The multi-level signal 212 output from the multi-level processing section 203 is also input to the error calculation processing section 204. The error calculation processing unit 204 includes an error distribution processing unit 202
The correction signal (signal before multi-level conversion processing) 212 for the pixel of interest, which is output from the above, is also input. The difference signal is calculated here, and the error signal 213 is determined.

Here, the error calculation processing unit 204 of the third embodiment does not simply calculate the error of the image signal using a constant error diffusion matrix, but holds a plurality of error diffusion matrices in advance. Error diffusion table 2
07 is selected by the random number signal 214 from the random number generation unit 206 and the error calculation processing unit 20 is selected.
4 and the error calculation processing unit 204 calculates a distribution value of each error for distributing the error signal to the peripheral pixels using the supplied error diffusion matrix.

FIG. 8 shows an example of the error diffusion matrix set in the error diffusion matrix table 207 used in the error calculation processing section 204. In the example shown in FIG. 8, when the random number value is “0”, the error diffusion matrix shown in (A) is selected, and the error signal is distributed to the lower pixels.
When the random number value is "1", the error diffusion matrix shown in FIG. 2B is selected and the error signal is distributed to the right pixel.

In FIG. 8, the mark * indicates the pixel of interest.

The error signal distributed for each pixel calculated by the error calculation processing unit 204 is added to the input image signal when the corresponding pixel is input from the image input unit 201 in the error distribution processing unit 202. Be included.

As described above, according to the third embodiment, by changing the error diffusion matrix in the pseudo halftone processing by using random numbers, a random number component is added to the image, thereby improving the resolution and gradation. It is possible to perform recording that satisfies both of them, and it is possible to suppress the occurrence of a false contour or the like.

[Other Embodiments] In the above description of the second embodiment, the controller 282 has been described as an example of a configuration for receiving the added random number control signal from the external device 159 (or the host computer). The image forming apparatus of the present invention is not limited to the controller
An additional random number control signal may be transmitted from another host computer or the like via a network such as an SI.

In the present invention, a full-color copying machine has been described as an example, but it is needless to say that the present invention is not limited to a full-color copying machine.

Even if 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.), an apparatus including one device (for example, a copying machine, a facsimile, etc.) Device).

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

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

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

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

Further, by downloading and reading out a program represented by software for achieving the present invention from a database on a network by a communication program, the system or apparatus can be
It is possible to enjoy the effects of the present invention.

[0079]

As described above, according to the present invention, both the resolution and the gradation are satisfied by performing dot control on the result of the multi-value pseudo halftone processing and changing the recording dot array position. Recording is enabled, and the occurrence of false contours and the like can be efficiently suppressed by simple control.

Further, according to the present invention, since the recording position is also changed by reflecting the random number value, the recording which satisfies both resolution and gradation for an image having regularity such as gradation is performed. And the generation of a false contour or the like can be efficiently suppressed by simple control.

Further, according to the present invention, by adding a random number component to an image by switching an error diffusion matrix in a pseudo halftone process by using a random number, it becomes possible to perform recording satisfying both resolution and gradation. The occurrence of contours and the like can be suppressed.

[0082]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus to which an embodiment of the present invention is applied.

FIG. 2 is a block diagram illustrating a detailed configuration of an image processing unit illustrated in FIG. 1 according to the embodiment;

FIG. 3 is a block diagram showing a detailed configuration of a dot control unit shown in FIG. 2 in the embodiment.

FIG. 4 is a diagram showing operation timings of the dot control unit shown in FIG. 3 in the present embodiment.

FIG. 5 illustrates a pseudo halftone processing unit according to the present embodiment;
FIG. 9 is a diagram illustrating an example of specific data processing when expressing seven values at a density of 200 (lines / inch) from a coded image signal.

FIG. 6 is a diagram illustrating a detailed configuration of a dot control unit according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of adding a random number component to an image by switching an error diffusion matrix using a random number in a pseudo halftone processing unit according to a third embodiment of the present invention.

8 is a diagram illustrating an example of an error diffusion matrix set in an error diffusion matrix table used in the error calculation processing unit illustrated in FIG. 7;

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum 2 corona charger 3 laser exposure optical system 3a polygon mirror 3a 3b, 33 lens 3c mirror 4y, 4c, 4Bk developing device 5 transfer device 5a transfer drum 5b transfer charger 5c adsorption charger 5d inner charger 5e outer charger Device 5f Recording material carrying sheet 5g Suction roller 5h Separation charger 5i Cam follower 6 Cleaning device 7a, 7b, 7c Recording material cassette 8a Separation claw 8b Roller 9 Heat roller fixing device 10 Tray 11 Pre-exposure lamp 12 Potential sensor 13 Light amount detection on drum Means 14 Fur brush 15 Backup brush 16 Oil removal roller 17 Backup brush 19 Transport path switching guide 20 Transport vertical path 21a Reverse path 21b Reverse roller 22 Intermediate tray 24y, 24m, 24c, 24Bk Eccentric cam 25 Eccentric cam 7a, 27b, 27c pickup roller 30 document 31 image processing unit 37 the controller unit of the platen glass 32 exposure lamp 33 lens 34 full-color sensor (CCD) 35 optical reading driving motor 36

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C262 AA24 AA26 AA27 AB13 BB08 BB20 BB33 BC01 GA21 2H027 EB01 2H030 BB02 BB12 5C077 LL04 MP06 MP08 NN07 NN12 PP32 PP33 PP38 PQ08 PQ23 RR02 TT03HTT06 9A001

Claims (16)

[Claims] 1. A processing means for performing multi-value pseudo halftone processing on image information, a developing means for developing the processing information by the processing means into dots, and a developing pixel position developed by the developing means is coordinated in a sub-scanning direction. An image processing apparatus comprising: a changing unit that changes the size of the developed pixel in response to an image; and an output unit that displays and outputs the developed pixel. 2. The developing means includes: converting means for converting the processing information by the processing means into a plurality of types of binary signals; and the changing means comprises a plurality of types of binary signals converted by the converting means.
2. The image processing apparatus according to claim 1, wherein the developing pixel position is changed by selecting one type of binary signal for each pixel from the value signals corresponding to the coordinate position in the sub-scanning direction. 3. The developing device according to claim 1, wherein the changing unit changes a developing pixel position to be expanded by the expanding unit in accordance with processing information from the processing unit together with the coordinate position in the sub-scanning direction. The image processing apparatus according to claim 1 or 2. 4. The apparatus according to claim 1, further comprising random number generating means for generating a random number for each pixel, wherein said changing means further changes a developed pixel position according to a random number value generated by said random number generating means. The image processing apparatus according to claim 1. 5. Generating means for generating a random number for each pixel of the image information, processing means for performing multi-value pseudo halftone processing on the image information, developing means for developing the processing information by the processing means into dots, Output means for displaying and outputting the dot pattern developed by the developing means, wherein the processing means performs multi-value pseudo halftone processing on the image signal by an error diffusion method, and generates the distribution ratio to peripheral pixels by the error diffusion method. An image processing apparatus characterized in that switching is performed by a random number value generated by a means. 6. The change of the distribution ratio to the peripheral pixels is performed by setting a plurality of types of error diffusion matrices in advance and switching one of the set matrices according to a random number generated by the generating means. The image processing apparatus according to claim 5, wherein: 7. The image processing apparatus according to claim 1, wherein the output unit is a printing unit that permanently and visually displays the image information. 8. An image processing method for performing multi-value pseudo halftone processing on image information, developing the processing information into a dot pattern, and displaying and outputting the dot information. An image processing method characterized in that the image processing method is varied in accordance with a scanning direction coordinate position. 9. The development into the dot pattern is performed by converting the halftone processing information into a plurality of types of binary signals, and the variation of the development pixel position is based on the conversion of the plurality of types of binary signals 9. The image processing method according to claim 8, wherein the developing pixel position is varied by selecting one type of binary signal for each pixel corresponding to the coordinate position in the sub-scanning direction. 10. The development pixel position variation according to claim 8, wherein the development pixel position is varied in accordance with the halftone processing information together with the sub-scanning direction coordinate position. Item 10. The image processing method according to Item 9. 11. The method according to claim 8, wherein a random number is generated for each pixel, and the development pixel position is varied according to the generated random number value. The image processing method according to any one of the above. 12. A multi-value pseudo halftone process on image information, expands the process information into a corresponding dot pattern, and, when displaying and outputting the expanded dot pattern, executes the halftone process by an error diffusion method. The image processing method according to any one of claims 1 to 3, wherein the image signal is subjected to multi-value pseudo halftone processing, and the distribution ratio to peripheral pixels is randomly changed by an error diffusion method. 13. The method of changing the distribution ratio to the peripheral pixels,
13. The image processing method according to claim 12, wherein a plurality of types of error diffusion matrices are set in advance, and one of the set matrices is switched by a randomly generated random value. 14. The image processing method according to claim 8, wherein the display output is a print output for permanently displaying image information. 15. A computer program sequence for realizing the function according to any one of claims 1 to 14. 16. A computer-readable recording medium storing a computer program for realizing the functions according to claim 1. Description: