JPH05176168A - Adaptive halftone processing system - Google Patents

Abstract

PURPOSE:To attain adaptive binarization in multi-stage with configuration of a small capacity memory by generating a final result of pseudo halftone processing based on the result of pseudo halftone processing with high gradation and on the result of pseudo halftone processing with high resolution. CONSTITUTION:An image area separate section 1 separates an input image into at least three kinds of image areas as a line image, a pattern and the edge of photograph and thin line. A generating section 5 for the result of halftone processing generates the final result of pseudo halftone processing based on the pseudo halftone processing by a pseudo halftone processing section 2 with high resolution and on the pseudo halftone processing by a pseudo halftone processing section 3 with high gradation and on the result of processing by the image area separate section 1. Thus, a delay line delaying data of the result of two kinds of the pseudo halftone processing is enough for the purpose by generating the result of the final pseudo halftone processing based on the two kinds of the pseudo halftone processing results subject to binarizing processing in this way and then the system is formed with a memory of a small capacity even when multi-stage adaptive binarization is implemented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adaptive halftone processing system for separating an image into image areas and performing multi-step adaptive binarization adapted to the separated areas.

[0002]

2. Description of the Related Art In a digital copying machine, a facsimile, etc., when reproducing an image in which a photograph portion, a halftone dot portion, and a line drawing portion such as a character are mixed, in order to obtain a reproduced image of high quality, a character area is It is effective to perform the processing that emphasizes the resolution and adaptively perform the processing that emphasizes the gradation on the pattern area (photograph, halftone dot portion).

In such adaptive processing, generally, binarization processing suitable for a character area and a picture area is performed in parallel on an input image, and the binarization processing is performed based on the result of image area separation. A method of selecting the selected image data is adopted.

Further, in order to improve the reproduction image quality of a document in which characters, photographs and halftone pictures are mixed, the image area is divided into three areas, that is, a character area, a photographic area and an intermediate area. Pseudo-halftone processing (adaptive binarization processing) suitable for the region is performed in parallel, and based on the results of the three types of image region separation, 2
There is an adaptive binarization method for selecting image data that has been binarized (The Institute of Image Electronics Engineers of Japan, Vol. 17, No. 5, 1988).
Years pp 301-307).

[0005]

By the way, in order to perform image area separation with high accuracy, it is necessary to perform image area determination processing using feature information of a somewhat wide area. Therefore, the image area separation processing takes a required time, and the processing result of the image area separation is output at a timing later than the processing result of the pseudo halftone. Therefore, a delay means is required to synchronize the image area separation result and the adaptive binarization processing result. In the case of the technique described in the above-mentioned paper, a means for delaying the three types of binarized data of the character area, the photograph area, and the intermediate area, that is, a memory or a line buffer is required, and the hardware amount is reduced. There is a problem in that the cost increases due to the increase.

It is an object of the present invention to provide an adaptive halftone processing method for performing multi-stage adaptive binarization with a small-capacity memory structure. Another object of the present invention is to provide an adaptive halftone processing method for reproducing the edge portion of a photographic image and the edge portion of a thick line drawing with high image quality. Still another object of the present invention is to provide an adaptive halftone processing method for reproducing a high quality image in an area where it cannot be determined whether it is a halftone dot or a line drawing.

[0007]

In order to achieve the above object, according to the invention of claim 1, the input image is separated into image areas,
In a method of adaptively performing pseudo-halftone processing on the separated area, first means for performing high-resolution pseudo-halftone processing on the input image, and high-gradation pseudo-halftone processing on the input image. Second means for performing halftone processing, means for separating the input image into at least three or more image areas, output based on the first means and second means, and output based on the image area separating means, And means for generating an output that has been subjected to pseudo halftone processing.

According to a second aspect of the present invention, means for delaying the outputs of the first means and the second means is provided, and the output of the image area separating means and the output of the first means and the second means are synchronized. It is characterized by taking.

According to a third aspect of the present invention, the means for generating the pseudo-halftone processed output is based on the outputs of the first means and the second means, and has the high resolution pseudo-halftone and the high gradation. Third means for performing pseudo-halftone processing having an intermediate characteristic of the pseudo-halftone, and selecting one of the outputs of the first, second, and third means based on the output of the separating means. And means for doing so.

In a fourth aspect of the invention, the third means selects the output of the first or second means when the outputs of the first means and the second means are the same, and the first means And the second
When the outputs of the means differ, the output binarized with a predetermined probability is selected.

In a fifth aspect of the present invention, the third means selects the output of the first or second means when the outputs of the first means and the second means are the same, and the first means Is ON and the output of the second means is OFF, the output binarized with the first probability is selected, and the output of the first means is OFF and the output of the second means is ON. In this case, the output binarized with the second probability is selected.

According to a sixth aspect of the present invention, the means for generating the pseudo-halftone processed output generates a control signal based on the output of the separating means, and the means for generating the control signal according to the generated control signal. And a means for selecting the outputs of the first means and the second means with a predetermined probability.

According to a seventh aspect of the present invention, the means for generating the pseudo-halftone processed output has a means for converting the output of the second means into multiple levels, an output of the multilevel conversion means and the first level. It is characterized in that it is provided with means for mixing the output of the means at a predetermined rate and means for converting the output of the mixing means into a multi-value by a pseudo halftone process.

According to an eighth aspect of the present invention, the probability is controlled by a periodic function in the main scanning direction and the sub scanning direction.

According to a ninth aspect of the present invention, the probability is controlled by a random function in the main scanning direction and the sub scanning direction.

According to a tenth aspect of the present invention, the third means performs processing with pseudo halftone having an intermediate characteristic with respect to the edge of the photographic image and the edge of the thick line drawing separated from the image area. It has a feature.

According to an eleventh aspect of the present invention, the third means is a pseudo halftone having an intermediate characteristic with respect to an image area where the image area separating means cannot judge whether it is a halftone dot or a line drawing. It is characterized by processing in.

[0018]

In the image area separating section, the input image is separated into three types of image areas or line images, patterns, photographs and thick line edges, or four kinds of line images, patterns, photographs and thick line edges, halftone dots or characters. .. In the part that generates the final pseudo-halftone processing result, based on the separation result of the image area separation unit, high-resolution pseudo-halftone processed data for the line drawing and high-gradation pseudo-halftone for the pattern For processed data, photographs and edges of thick lines and halftone dots or characters, intermediately processed data of those data is selected and output.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram of the present invention. In FIG. 1, the image area separation unit 1 is, as described later,
It is composed of an edge separating section, a halftone separating section, a white background separating section and a judging circuit, and separates into at least three kinds of image areas of a line drawing, a pattern, a photograph and an edge of a thick line. Further, in the present embodiment, a processing unit 2 that performs high resolution pseudo halftone processing,
A processing unit 3 that performs high-gradation pseudo-halftone processing; a delay line 4 that synchronizes with the processing result of the image area separation unit 1;
It is composed of a generation unit 5 which generates a final pseudo halftone processing result based on the pseudo halftone result by the processing units 2 and 3 and the processing result of the image area separation unit 1.

Then, as will be described later, the generation unit 5 for generating the final pseudo halftone processing result generates the pseudo halftone processing result having at least three kinds of characteristics, and thereby, the multistage adaptive Binarization processing is performed. That is, in the above-described conventional technique, when performing n-stage adaptive processing, it is necessary to provide a delay line for delaying n types of pseudo halftone processing results.
Since the final halftone processing result is generated from two types of binary halftone processing result data, only the delay line for delaying the two types of pseudo halftone processing result data is used. Is required and multi-stage adaptation 2
Even if the value is converted, the number of delay lines can be reduced as compared with the conventional one, so that the memory can be configured with a small capacity. If the time required for one or both pseudo halftone processing results is about the time required for the image area separation processing, it is not always necessary to provide the delay line.

This embodiment will be described in detail below. As shown in FIG. 2, the processing unit 2 that performs high resolution pseudo halftone processing performs simple binarization with the MTF correction circuit 21 that emphasizes edges. It is composed of the binarization circuit 22, and is a part mainly for reproducing characters in high resolution. FIG. 3 shows an example of a filter that performs MTF correction.

A processing unit 3 for performing pseudo halftone processing with high gradation
As shown in FIG. 4, it comprises a smoothing circuit 41 and a dither processing unit 42 which binarizes by a systematic dither method or an error diffusion method, and generates a moire pattern image (halftone image, photographic image). Instead, it is a part that reproduces in high gradation.
FIG. 5 shows an example of the smoothing filter.

FIG. 6 is a diagram showing the structure of the image area separating section 1.
Edge separation unit 11, halftone dot separation unit 12, and white background separation unit 1
3 and the determination circuit 14. The edge separation unit 11 converts the input image signal into a binary signal of black / non-black and white / non-white by a predetermined threshold value, and converts the converted black pixel,
Detect the connectivity of white pixels by pattern matching,
An area in which a connected black pixel and a connected white pixel are present in a local area is separated as an edge (for the edge separation method, the applicant of the present invention has reported that IEICE Technical Report IE90-29 to 38 1990). The method announced on July 27, 2007 was used). As a result, the edges of the line drawing and the photographic image are separated, and the flat portion of the photographic image is separated as a non-edge.

The halftone dot separating section 12 detects pixels (peak pixels) corresponding to peaks and valleys of halftone dots in the local area, and separates the halftone dot area according to the density of the peak pixels (this halftone dot separating method). The method described in the above-mentioned paper was also used). As a result, the halftone dot area is separated as a halftone dot, and the line drawing is separated as a non-halftone dot.

The white background separating unit 13 separates characters of a normal size by using a white background and a white background only in one direction at the edge of a photographic image. FIG. 7 shows the configuration of the white background separation unit 13. That is, after the input image signal is sharpened by the MTF correction filter in the MTF correction circuit 131, the binarization circuit 132 binarizes the image signal into white / non-white according to a predetermined threshold, and the pattern and matching circuit. Input to 133.

FIG. 8 shows a 5 × 5 matrix out of a 5 × 5 matrix.
2 or 2 × 5 indicates a pattern of clusters of white pixels, all of which are white pixels. The pattern matching circuit 133 detects a group of white pixels near the target pixel by pattern matching. Then, in the determination circuit 134, as shown in FIG. 9, when there is a cluster of white pixels in both directions in the main scanning direction across the target pixel, that is, (logical sum of all pixels on the left side of the target pixel) AND (target OR of all pixels on the right side of pixel) = 1
The target pixel (region) that satisfies the above condition is separated as a white background region.
As a result, the peripheral area of the normal size character including the white background is separated as the white background. On the other hand, since the white background area is detected only in one direction with respect to the pixel of interest around the edge portion of the thick character (line drawing) and the photographic image, it is separated as a non-white background. Most of the area inside the pattern is separated as a non-white background.

Based on the separation results of the edge separation, the halftone dot separation, and the white background separation, the determination unit 14 of the image area separation unit 1 determines the line drawing, the pattern, the photograph, and the thick line as shown in FIG. Separated into three types of image areas of edges. Then, based on this separation result information, the image data that has been subjected to high resolution pseudo halftone processing is selected for the line drawing area,
Image data that has been subjected to high gradation pseudo-halftone processing is selected for the pattern area, and pseudo-halftone with intermediate characteristics of high resolution and high gradation is selected for photographs and thick line edges. The processed image data is selected.

As described above, it is difficult to distinguish the edge of a photographic image from the edge of a thick line drawing. Therefore, basically both edges must be subjected to the same pseudo halftone processing. Then, when high-gradation pseudo-halftone processing is applied to the edge according to the prior art, deterioration of resolution becomes a problem at the edge portion of a thick line drawing, and when high-resolution pseudo-halftone processing is applied. Shows that the edge portion of the photographic image is emphasized too much and the deterioration of the image quality is noticeable. Therefore,
In the present embodiment, by performing processing having an intermediate characteristic on both edges, it is possible to reproduce an image with little deterioration in image quality.

FIG. 11 is a diagram showing an example in which four types of image areas are separated. Generally, in the halftone dot separation described above,
Since it is difficult to determine a halftone dot, especially a halftone dot of a color image, and a small character, the halftone dot is not separated from the halftone dot / non-halftone dot as shown in FIG. / Dots or characters / non-dots are divided into three types, and in the determination circuit 14 of FIG. 6, image areas are separated into four types: line drawing / pattern / photograph and thick line edge / dots / characters. Then, based on this image area separation result, multi-stage (three or more types) adaptive binarization is performed.

As described above, in halftone dot separation, it is difficult to distinguish especially small characters from halftone dots, and when the characters are processed as a picture, the image quality of the resolution is remarkably deteriorated. Causes texture disorder and a decrease in the number of gradations, resulting in deterioration of image quality. Therefore, in the present embodiment, in the halftone dot separation, the halftone dot or halftone dot or the character / non-halftone dot is divided into three stages to reproduce the halftone dot or character region with an intermediate characteristic to obtain the image quality. It is possible to obtain an image with little deterioration.

Hereinafter, some methods of this embodiment for generating pseudo halftone processing data having intermediate characteristics of high resolution and high gradation will be described.

FIG. 12 is a diagram showing the structure of the halftone processing result generating section 5 of FIG. 1, which is composed of a section 51 for generating data having intermediate characteristics and a selecting section 52. Then, the first method has intermediate characteristics based on the image data 53 that has been subjected to high resolution pseudo halftone processing and the image data 54 that has been subjected to high gradation pseudo halftone processing. Intermediate data 5
5 is generated, and one of the three data of high resolution pseudo halftone processing data 53, intermediate data 55, and high gradation pseudo halftone processing data 54 is selected based on the result of image area separation.

FIG. 13 is a diagram showing the output logic of the intermediate data generator 51. That is, when the high-resolution pseudo-halftone data 53 and the high-gradation pseudo-halftone data 54 are the same (both 0 or 1), the high-resolution pseudo-halftone data 53 and the high-gradation are used as the intermediate data 54. When both the pseudo halftone data 54 are 0, 0 is output, and when both are 1, 1 is output.

If the high-resolution pseudo-halftone data 53 and the high-gradation pseudo-halftone data 54 are different, u (x, y) is output as the intermediate data 54. FIG. 14 shows u
An example of the output matrix of (x, y) is shown. That is, x is a 2-bit counter value (x = 0, 1, 2, 3, 0, which is counted for each pixel in the main scanning direction).
1. ． ． ． ), And y is a 2-bit counter value (x = 0, 1, 2, ...) Counted for each line in the sub-scanning direction.
3, 0, 1. ． ． ． ). Then, as shown in FIG. 14, a value u (x, y) determined by the position information (x, y)
y) is set. In this example, the appearance probabilities of 1 and 0 are the same value (8/16), but they may be other values. Therefore, high resolution pseudo halftone data 53,
If the high gradation pseudo halftone data 54 is different, the value of u (x, y) corresponding to the position is output as the intermediate data 54.

As a result, an intermediate characteristic is obtained, the white part of the edge is reproduced with a density slightly higher than that of the pseudo halftone process of high resolution, and the black part of the edge is pseudo halftone process of high gradation. The reproduction is performed with a slightly higher density than that, and therefore, the edge of the photographic image and the edge of the thick character can be reproduced with high image quality. Edge contrast becomes too strong and image quality deteriorates). For example, with respect to the separation result shown in FIG. 10, the selection circuit 52 selects the high-resolution pseudo-halftone processed data for the line drawing and the high-gradation pseudo-halftone processing for the pattern. By selecting the data and selecting the intermediate data of the intermediate data generation unit 51 for the photograph and the edge of the thick line, it is possible to reproduce a high-quality image.

FIG. 15 shows high resolution pseudo halftone data 5
3 is a second example of the intermediate data generation logic in the case where 3 and the high gradation pseudo-halftone data 54 are different. In this example, depending on which output is 1 (ON), uA (x,
y) and uB (x, y) are switched. uA (x,
The output matrix of y) and uB (x, y) is shown in FIG. Further, values are set between uA (x, y) and uB (x, y) such that uA (x, y) = not {uB (x, y)}. Here, x and y are the same as those described above.

According to the second method, in addition to the effect of the first method described above, ON (1) in the local region is obtained.
Since the number of / OFF (0) can be basically the same for the high-gradation pseudo-halftone processed data and the intermediate data, the density is preserved, and therefore, the processing having the intermediate characteristics inside the pattern is performed. Even if mistakenly applied, there is an advantage that the image quality deterioration is not noticeable even though the resolution is improved. This second
The method is particularly effective when applied to an area where it cannot be determined whether it is a character or a halftone dot. For example, in FIG.
For the separation result shown in FIG. 1, the selection circuit 52 selects the high-resolution pseudo-halftone processed data for the line drawing and the high-gradation pseudo-halftone processed data for the pattern. However, for photos and thick line edges,
3. By selecting the intermediate data generated by the first method described in FIG. 14 and selecting the intermediate data generated by the second method for halftone dots or characters, a high-quality image can be obtained. Playback is possible.

FIG. 17 is a diagram showing the configuration of the second embodiment of the halftone processing result generator 5 of FIG. In this embodiment, based on the image area separation result, the u generation unit 511
Any of the four types of output matrices u1 to u4 shown in FIG. 18 is output (x and y are the same as those described above), and the output data generation unit 522 responds to the outputs u1 to u4 of the generation unit 511. , The high-resolution pseudo-halftone processed data 53 and the high-gradation pseudo-halftone processed data 54 are stochastically selected.

That is, based on the result of image area separation, u
Select 1, u2, u3, u4, and select 1 for the value of u
/ 0 selects high resolution pseudo halftone processing data and high gradation pseudo halftone processing data. Generation unit 511
When u1 outputs u1, high-resolution pseudo-halftone processing data is always selected, and when the generation unit 511 outputs u4, high-gradation pseudo-halftone processing data is always selected. In the case of u2, high-resolution pseudo-halftone processed data is selected with a probability of 12/16, and high-gradation pseudo-halftone processed data is selected with a probability of 4/16. In the case of u3, high-resolution pseudo-halftone processed data is selected with a probability of 8/16, and high-gradation pseudo-halftone processed data is selected with a probability of 8/16.

For example, with respect to the image area separation result shown in FIG. 11, the generation unit 511 outputs u1 for a line drawing, u4 for a pattern, and u for a photograph and an edge of a thick line.
2 is output and u3 is output in the case of a halftone dot or a character, and the output data generation unit 522 generates final pseudo-halftone data according to the value of u (x, y), so that a high-quality image is reproduced. can do. The present embodiment is particularly effective when switching from high resolution to high gradation in a large number of stages,
When u (x, y) is a 4 × 4 matrix as in the embodiment, 16 steps can be switched.

In the above first and second embodiments, the value of u is set to a periodic value determined by the position information (x, y). However, as shown in FIG. A random number generator for generating a real value between 1 is provided, a threshold value is set according to the result of image area separation, and a comparator determines whether or not the threshold value is larger than the threshold value, thereby performing main scanning. The u value in the scanning direction and the u value in the sub scanning direction can be set to 1/0. In the embodiment using this random number, the texture at the edge portion is eliminated, the image quality is improved, and continuous adaptive processing control can be easily realized.

As another embodiment, as shown in FIG. 20, multi-valued data is obtained based on the high-tone pseudo-halftone processing result or the pseudo-halftone processing result data including the surroundings. High-resolution pseudo-halftone processed data is mixed at a mixing rate set by the image area separation result, and again multi-valued by pseudo-halftone processing to generate intermediate data having intermediate characteristics. In the present embodiment, since the high gradation pseudo halftone processing result is multi-valued and then mixed, it is possible to continuously switch from high resolution to high gradation, and intermediate data having more accurate intermediate characteristics can be obtained. Can be generated, and is particularly effective when the pseudo halftone process is multi-valued.

The pseudo halftone processing is not limited to the method described in the above embodiment, and another method may be used. Also, although the two methods described with reference to FIGS. 12 and 17 are different in how to use the image area separation result, there is no great difference between the two methods, and one of the two having the smaller hardware amount in consideration of the system configuration to be adopted. Can be selected, or both can be combined.

[0044]

As described above, according to the first and second aspects of the present invention, a final pseudo halftone processing result is generated from two types of binarized pseudo halftone processing results. Therefore, a delay line for delaying the data of the two types of pseudo halftone processing results is sufficient, and a small-capacity memory can be used even when performing multi-stage adaptive binarization. According to the third aspect of the invention, since the pseudo halftone processing suitable for the separated image area is performed, it is possible to reproduce a high quality image. According to the fourth aspect of the present invention, if the high-resolution pseudo-halftone processed output and the high-gradation pseudo-halftone processed output are not the same, 2 with a predetermined probability.
Since the value is set, the quality of the edge portion of the photographic image is improved. Further, in the case of the same, high-resolution pseudo-halftone or high-gradation pseudo-halftone data is output, so that the image quality of the edge portion of thick characters or solid figures is improved. According to the invention described in claim 5, ON in the local region
Since the number of (1) / OFF (0) can be basically the same, even if the intermediate characteristic process is erroneously applied to the inside of the pattern, the image quality is not conspicuous even though the resolution is improved. Further, it is possible to reproduce a photograph, a thick line edge, a halftone dot or a character with a high quality image. According to the sixth aspect of the present invention, a high-resolution pseudo-halftone processed output and a high-gradation pseudo-halftone processed output have a predetermined probability in accordance with a control signal generated based on the separation result. Since it is selected in step 1, it is possible to switch from high-resolution pseudo-halftone to high-gradation pseudo-halftone in multiple steps or continuously, and intermediate data having various intermediate characteristics can be generated. According to the seventh aspect of the invention, since the high gradation pseudo-halftone processing data is multi-valued and then mixed with the high-resolution pseudo-halftone processing data, a more accurate intermediate characteristic is obtained. Intermediate data can be generated. According to the invention described in claim 8, since the probability is controlled by the periodic function, the probability can be controlled by the simple hardware. According to the invention described in claim 9, although hardware for generating a random number is required, texture at the edge portion is eliminated, image quality can be improved, and continuous adaptive processing control can be easily performed. it can. According to the invention of claim 10,
The edges of the photographic image and the edges of the thick line drawing are processed in pseudo-halftone, which has intermediate characteristics, so the resolution of the edges of the thick line drawing does not deteriorate and the edges of the photographic image are emphasized. The image can be reproduced without being displayed. According to the invention of claim 11,
Since halftone dots or character areas are reproduced with intermediate characteristics, there is no deterioration in the image quality of the resolution when the characters are processed as pictures, and the texture distortion and floor when halftone dots are processed. It is possible to reproduce an image with little deterioration in image quality without reducing the number of keys.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of the present invention.

FIG. 2 is a diagram illustrating a configuration of a high resolution pseudo halftone processing unit.

FIG. 3 is a diagram showing an MTF correction filter.

FIG. 4 is a diagram illustrating a configuration of a high-gradation pseudo-halftone processing unit.

FIG. 5 is a diagram showing a smoothing filter.

FIG. 6 is a diagram showing a configuration of an image area separation unit.

FIG. 7 is a diagram showing a configuration of a white background separation unit.

FIG. 8 is a diagram showing a pattern of clusters of white pixels.

FIG. 9 is a diagram showing a detection mask for a white background area.

FIG. 10 is a diagram in which the image area is divided into three types according to the present embodiment.

FIG. 11 is a diagram in which the image area is divided into four types according to the present embodiment.

FIG. 12 is a diagram showing a configuration of a halftone processing result generation unit.

FIG. 13 is a diagram showing an output logic of an intermediate data generation unit.

FIG. 14 is a diagram showing an output matrix of intermediate data.

FIG. 15 is a second example of intermediate data generation logic.

FIG. 16 is a diagram showing another example of an output matrix.

FIG. 17 is a diagram showing another configuration of the halftone processing result generation unit.

FIG. 18 is a diagram showing still another example of the output matrix.

FIG. 19 is another embodiment of randomly controlling the output matrix.

FIG. 20 is another embodiment for generating intermediate data.

[Explanation of symbols]

 1 Image Area Separation Section 2 High Resolution Pseudo Halftone Processing Section 3 High Gradation Pseudo Halftone Processing Section 4 Delay Line 5 Halftone Processing Result Generation Section 11 Edge Separation Section 12 Halftone Separation Section 13 White Background Separation Section 14 Judgment Circuit

Claims (11)

[Claims] 1. A system in which an input image is separated into image areas, and pseudo halftone processing is adaptively performed on the separated areas,
First means for performing high-resolution pseudo-halftone processing on the input image, second means for performing high-tone pseudo-halftone processing on the input image, and at least three or more types of input images And a means for generating a pseudo-halftone-processed output based on the outputs of the first and second means and the output of the image area separating means. Adaptive halftone processing method. 2. A means for delaying the outputs of the first means and the second means is provided, and the output of the image area separating means is synchronized with the outputs of the first means and the second means. The adaptive halftone processing method according to claim 1. 3. The means for generating the pseudo-halftone-processed output is configured to output the high-resolution pseudo-halftone and the high-gradation pseudo-halftone based on the outputs of the first means and the second means. Third, performing pseudo halftone processing having intermediate characteristics
Means and the output of the separating means, the first,
2. The adaptive halftone processing method according to claim 1, further comprising means for selecting one of the outputs of the second and third means. 4. The third means selects the output of the first means or the second means when the outputs of the first means and the second means are the same, and outputs the outputs of the first means and the second means. When different,
4. The adaptive halftone processing method according to claim 3, wherein the binarized output is selected with a predetermined probability. 5. The third means selects the output of the first or second means when the outputs of the first means and the second means are the same, and when the output of the first means is ON, the third means is selected. When the output of the second means is OFF, the output binarized with the first probability is selected, and when the output of the first means is OFF and the output of the second means is ON, the second probability is selected. 4. The adaptive halftone processing method according to claim 3, wherein the binarized output is selected. 6. The means for generating the pseudo-halftone processed output includes means for generating a control signal based on the output of the separating means, and the first control circuit according to the generated control signal.
2. The adaptive halftone processing method according to claim 1, further comprising means for selecting the outputs of the means and the second means with a predetermined probability. 7. The means for generating the pseudo-halftone processed output has a predetermined means for converting the output of the second means into a multi-valued output and the output of the multi-valued output means and the output of the first means. 2. The adaptive halftone processing method according to claim 1, further comprising means for mixing at a rate of 1 and a means for converting the output of the mixing means into a multi-value by pseudo halftone processing. 8. The adaptive halftone processing method according to claim 4, wherein the probability is controlled by a periodic function in the main scanning direction and the sub scanning direction. 9. The adaptive halftone processing method according to claim 4, wherein the probability is controlled by a random function with respect to the main scanning direction and the sub scanning direction. 10. The method according to claim 3, wherein the third means performs processing with a pseudo halftone having an intermediate characteristic with respect to an edge of the image area-separated photographic image and an edge of a thick line drawing. Adaptive halftone processing method. 11. The third means performs processing with pseudo halftone having an intermediate characteristic for an image area in which it is impossible to determine whether the image area separating means is a halftone dot or a line drawing. The adaptive halftone processing method according to claim 3.