JPH04287564A - Picture processor - Google Patents

Abstract

PURPOSE:To set optimum resolution automatically to send or store required information without leaving judgement to the operator. CONSTITUTION:A control section 16 reads a picture data at a maximum resolution of a picture read section 11, sends it to a binarizing processing section 12 to implement binarizing processing. Then a resolution detection processing section 14 makes calculation for resolution detection and stores a binarized picture data to a picture memory. The redundancy of the resolution is discriminated from the result of the resolution detection processing section 14 and when it is discriminated that a redundancy is in existence in the read resolution, the stored picture data is read and a resolution conversion processing section 15 implements the resolution conversion processing and the resolution is again detected to the converted picture data and the result is again stored in the picture memory 13. Thus, the resolution is sequentially converted and the picture data in which the required minimum resolution is automatically set is coded and the result is sent to an opposite device through a communication line with the set resolution.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus such as a facsimile machine.

0002

2. Description of the Related Art Conventionally, in a facsimile, for example, a G4 facsimile, the resolution of a read image is 400×4.
00DPI (Dot Per Inch), 200×2
It has multiple resolutions such as 00DPI and 200×100DPI, and the operator judges the content of the document to be sent in advance.
Based on the results, the desired resolution is selected and set. For example, if the content is more important than the quality of the image, such as a document image, set a high resolution, or if the document to be sent does not require high resolution, to save communication time. You are setting a low resolution.

0003

However, in the conventional example described above, it is difficult for the operator to always set the optimum reading resolution for the image to be transmitted. For example, if you select a resolution lower than the required reading resolution, information will be lost and become unreadable on the receiving side, and if you select a resolution higher than the required reading resolution, communication time and costs will increase. There were problems such as waste of money.

[0004] Furthermore, in devices that can store image data in memory, it is possible to print out the stored images and check whether the transmission resolution is set correctly, but this is a cumbersome operation. There were also problems such as wasted time. The present invention has been made to solve the above problems, and provides an image processing device that can automatically set the optimal resolution for transmitting or storing necessary information without relying on the operator's judgment. The purpose is to

[0005]

Means and Effects for Solving the Problems In order to achieve the above object, an image processing apparatus of the present invention has the following configuration. In other words, the read image data is binarized and
In an image processing device that converts and outputs the resolution of digitized image data, the resolution detecting means detects the resolution of the image data, and the resolution of the image data is converted based on the detection result of the resolution detecting means. resolution converting means, the resolution detecting means detects the resolution of the binarized image data and the resolution of the image data converted by the resolution converting means, and the resolution converting means includes: The present invention is characterized in that the conversion can be executed multiple times based on the detection result.

Preferably, the conversion magnification in the resolution conversion means is 1/2.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the basic configuration of an image processing apparatus in this embodiment. In the figure, reference numeral 11 denotes an image reading section, which has a function of performing shading correction and the like on analog data read by an image pickup device such as a CCD, and then A/D converting the data into digital data and outputting the same. 12 is a binarization processing section;
The multi-valued data from the image reading unit 11 is subjected to edge enhancement processing, which will be described later, and is binarized by comparing it with a predetermined threshold. Reference numeral 13 denotes an image memory, which has a capacity capable of storing one or more pages of binarized image data. 14 is a resolution detection processing section, and a binarization processing section 12
The resolution required for transmission is detected from the image data binarized in , and the image data subjected to resolution conversion by a resolution conversion processing section 15 , which will be described later. Reference numeral 15 denotes a resolution conversion processing section, which converts the resolution of the image data stored in the image memory 13 when the resolution detection processing section 14 determines that there is redundancy in the resolution (for example, at a resolution of 400 x 400 DPI). Stored image data at 200 x 200 DPI
(The amount of data can be reduced by converting the image data once converted to 200 x 200 DPI to 200 x 100 DPI). 16 is a control unit;
It is composed of a microprocessor (MPU), RAM, ROM, etc., and controls the operation of each processing unit according to a control procedure (program) stored in the ROM.

Next, the processing procedure in this embodiment will be explained below with reference to the flowchart shown in FIG. In this embodiment, the image is read at the maximum resolution of the image reading unit 11, and if there is redundancy in the read image data,
This reduces the amount of data by converting to a lower resolution.

First, in step S1, the control section 16
instructs the image reading unit 11 to start reading, and reads the image data at the maximum resolution that the image reading unit 11 has. Then, in step S2, the read image data is sent to the binarization processing section 12 to perform binarization processing. Next, when the binarization process is completed, the process proceeds to step S3, and the resolution detection processing section 14 performs calculations for resolution detection. Then, in step S4, the binarized image data is stored in the image memory.

[0010] Next, in step S5, it is determined whether or not reading has been completed. If not, the process returns to step S1 and the above-described process is repeated. However, once the reading and accumulation of all pixels is completed, the process advances to step S6, and a resolution redundancy determination is performed based on the result in the resolution detection processing section 14. As a result, if it is determined that there is no redundancy in the reading resolution, the process ends.

On the other hand, if it is determined that there is redundancy, the process advances to step S7, where the image data stored in the image memory 13 is read out, and in the next step S8, resolution conversion processing is performed by the resolution conversion processing section 15, which will be described later. and reduce the amount of data. Then, in step S9, the converted image data is subjected to resolution detection processing again, and is stored in the image memory 13 again in step S10. Then, in step S11, it is determined whether or not the conversion and detection processing has been completed for all pixels. If not, the process returns to step S7 and the above-described processing is repeated. Thereafter, when the process is completed, the process proceeds to step S12, and redundancy determination of the resolution is performed based on the result in the resolution detection processing section 14. As a result, if it is determined that there is still redundancy in the resolution of the converted image data, steps S7 to S11 are further performed.
Repeat the process.

[0012] In this way, the image data whose resolution has been sequentially converted and the minimum required resolution has been automatically set is encoded and transmitted to the other party's device at the set resolution through a communication line (not shown). Next, the specific configuration of each processing section described above will be explained in detail. First, FIG. 3 is a diagram showing an example of the timing of an image signal read by the image reading section 11. As shown in the figure, the image data 34 is inputted as one pixel data in synchronization with the image clock 33, further becomes image data for one line in synchronization with the line synchronization signal 32, and then synchronized with the page synchronization signal 31. and input as image data for one page.

FIG. 4 shows the resolution conversion processing section 1 in this embodiment.
5 is a block diagram showing the configuration of No. 5. FIG. In this embodiment, a case where thinning is simply performed as resolution conversion processing will be described. In the figure, 41 is a conversion setting section, and 2
It is composed of a bit register, and a code corresponding to "conversion present", etc., which performs conversion for each of main scanning and sub-scanning, is set. Note that this setting is performed by the control section 16 before starting the process, according to the determination result from the resolution detection processing section 14. Further, with this setting, it is also possible to perform conversion only in one direction of main scanning or sub-scanning. 42 is a line synchronization signal control unit, and when “conversion enabled” is set in the conversion setting unit 41, the line synchronization signal 32
The synchronization signal is thinned out every time, and the thinned out conversion line synchronization signal 32' is output. Reference numeral 43 denotes an image clock control section, which similarly thins out the clock every image clock 33 and outputs a converted image clock 33' when "conversion is present" is set in the conversion setting section 41.

[0014] By performing thinning processing on each control signal in this way, the resolution of image data is converted and the amount of data is reduced. FIG. 5 is a diagram showing each synchronization signal when conversion is performed for each of main scanning and sub-scanning. As shown in the figure, when both main scanning and sub-scanning are converted, the amount of data is 1/4 times as large (if compression encoding is not performed). Figure 6
1 is a block diagram showing the configuration of a binarization processing section 12 in this embodiment. In the figure, reference numeral 61 denotes an edge enhancement processing section, which enhances the edges of image data using a Laplacian filter, which is a spatial filter, or the like. A comparator 61 compares the input signal with a predetermined threshold value and performs binarization.

In this embodiment, edge enhancement processing is performed to perform binarization, but the configuration of the binarization processing section 12 is not limited to this, and various modifications are possible. FIG. 7 is a block diagram showing the configuration of the resolution detection processing section 14 in this embodiment. In the figure, 71a and 71b are line buffers for one line, and 72a to 72f are one-pixel delay elements. Reference numeral 73 denotes a pattern matching processing section, which is composed of, for example, a ROM or the like. 74 is a counter that counts pattern matching results. Further, 75 is a resolution determination unit that determines redundancy of resolution from the result of count 74.

In the above configuration, the binarized image data is extracted as nine pixels A to I as shown in FIG. 8 by line buffers 71a-b and one-pixel delay elements 72a-72f. Then, in the pattern matching processing section 73, a match is made with a preprogrammed thin line pattern, and if there is a match, "1" is output, and if none of them match, "0" is output. The pattern matching results are input to a counter 74, and the matching results are counted for one page of image data. When the processing for one page is completed, the resolution redundancy determination unit 75 performs resolution redundancy determination based on the count value of the counter 74, and the result is output to the control unit 16.

Next, the above pattern matching process will be explained in detail. First, when the document to be read requires high resolution (for example, when there are many small characters, line drawings, etc.), many thin line patterns as shown in FIG. 9 are detected. If an image having many such thin lines with a width of one pixel is thinned out by resolution conversion, there is a high possibility that the thin lines will disappear. In other words, in this case, if the read original is converted to a resolution lower than this, information will be lost, and for example, there is a possibility that the received original cannot be read by facsimile.

Therefore, in this embodiment, blocks containing thin lines are detected by pattern matching (blocks in which a 3×3 matching block is matched as a thin line pattern), and the total number of thin line blocks in one page is calculated. Set the resolution as a criterion. In other words, in this embodiment, if the sum of the thin line blocks exceeds a preset reference value, it is determined that a high resolution is required, and the resolution conversion process is not performed and the process is terminated. For example, facsimile can be transmitted at high resolution (400 x 400 DPI).

On the other hand, if the sum of the thin line blocks is less than the reference value, it is determined that there is redundancy in the reading resolution, and the resolution conversion processing section 15 performs thinning processing to convert to a lower resolution (200×200 DPI). Furthermore, redundancy is determined again for the converted image. For example, in the case of a facsimile, if the thin line in the main scanning direction is equal to or higher than the reference value, the resolution in the sub-scanning direction is converted and the resolution is lowered to 200×. Perform thinning processing to 100DPI.

As explained above, according to this embodiment,
The magnification of the resolution conversion processing section is limited to 1/2, and the conversion process is repeated until it is determined that there is no redundancy for the images stored in the image memory, thereby automatically setting the required minimum resolution. Therefore, no matter what resolution is finally converted, the minimum window size for thin line detection can be realized with 3×3 pixels, and the configuration of the resolution detection processing section becomes simple. For example, when converting the resolution to 1/4 in both main scanning and sub-scanning, if the resolution conversion processing unit 15 converts the resolution to 1/4 at a time, it is necessary to detect thin lines with a line width of up to 3. Therefore, the minimum window size for pattern matching is 5×5 pixels, and the resolution detection processing section 14 becomes complicated.

[0021] Then, in the facsimile, the image data is sent onto the communication line using the resolution converted as described above as the resolution parameter for actually sending.

[0022]

[Other Embodiments] In the above-mentioned embodiments, the setting of whether or not to perform resolution conversion is set by pattern matching. However, the method is not limited to the above-mentioned method. A possible method is to determine the complexity of the image using the histogram of , and set whether or not to perform resolution conversion using the sum of small run lengths as a determination criterion.

Furthermore, the window size for pattern matching is not limited to 3×3 pixels, and more accurate determination can be made by using a larger window. Further, in this embodiment, the resolution conversion processing section is explained as simple thinning processing, but the present invention is not limited to this, and conventionally proposed interpolation processing or the like may be used.

Furthermore, the image memory may be not only a semiconductor memory but also any type of memory such as a hard disk or an optical disk.

[0025]

[Effects of the Invention] As explained above, according to the present invention,
By automatically setting the optimal resolution for transmitting or storing necessary information without relying on the operator's judgment, it is possible to save communication time and memory.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of an image processing device in this embodiment.

FIG. 2 is a flowchart showing a processing procedure in this embodiment.

FIG. 3 is a diagram showing the timing of input image signals.

FIG. 4 is a block diagram showing the configuration of a resolution conversion processing section.

FIG. 5 is a timing signal showing resolution conversion.

FIG. 6 is a block diagram showing the configuration of a binarization processing section.

FIG. 7 is a block diagram showing the configuration of a resolution detection processing section.

FIG. 8 is a diagram showing reference pixels for pattern matching in this embodiment.

FIG. 9 is a diagram showing an example of a thin line detection pattern.

[Explanation of symbols]

11 Image reading section 12 Binarization processing section 13 Image memory 14 Resolution detection processing section 15 Resolution conversion processing section 16 Control section

Claims (2)

[Claims] [Claim 1] Binarize the read image data, and
In an image processing device that converts and outputs the resolution of digitized image data, the resolution detecting means detects the resolution of the image data, and the resolution of the image data is converted based on the detection result of the resolution detecting means. resolution converting means, the resolution detecting means detects the resolution of the binarized image data and the resolution of the image data converted by the resolution converting means, and the resolution converting means includes: An image processing device characterized in that conversion can be executed multiple times based on the detection result. 2. The conversion magnification in the resolution conversion means is:
The image processing apparatus according to claim 1, wherein the image processing apparatus is 1/2 times as large.