JP2000207533A - Image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove rear image copied together with surface image on an original regardless of paper kind of the original without complicating device constitution and without largely affecting FCOT. SOLUTION: An image processor has an original platen 11 where an original is placed and a cover 12 covering the original platen 11 so that it can be opened/closed for optically reading the original being a read object. A transmissivity information acquirement means for acquiring transmissivity information on the transmissivity of the original by comparing image information obtained from the original on the original platen 11 when the cover 12 is closed with image information obtained from the original on the original platen 11 when the cover 12 is not closed is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of optically obtaining image information from a fixed original and performing image processing on the image information, such as a fixed original copy machine. The present invention relates to an image processing device.

[0002]

2. Description of the Related Art Generally, in an image processing apparatus such as a copying machine,
Since the image information is read optically, if a document with images recorded on both sides of a sheet with high light transmittance (very thin sheet or tracing paper) is to be read, only one side of the document is read. However, even when reading is performed, there is a possibility that so-called show-through occurs in which image information is read in a state where the front and back images are combined. To reduce or eliminate the occurrence of such show-through,
Some image processing apparatuses use a dedicated sensor to detect the paper quality of a document to be read and perform density correction according to the detection result (see, for example, Japanese Patent Application Laid-Open No. 5-56257).
There is a configuration in which the amount of show-through is obtained from the reading result of both sides of a document to remove show-through (for example, see Japanese Patent Application Laid-Open No. 6-62216).

Further, in the image processing apparatus, in addition to an original using white paper, an original having a different color density (hereinafter referred to as "background density") of the paper itself, such as newsprint or colored paper, may be read. is there. Therefore, in order to obtain an optimum output even when such a document is to be read, some image processing apparatuses detect the background density of the document to be read, and respond to the detection result. (Hereinafter, this correction is referred to as “background removal”) (for example, Japanese Patent Application Laid-Open Nos. 7-27399, 7-322069, and 7-749).
No. 52). With an image processing apparatus that performs such background removal, the occurrence of show-through can be reduced or eliminated by setting the background removal amount to be large.

In an image processing apparatus that obtains image information from a fixed original, an original mounting table on which an original to be read is mounted and a platen cover that covers the original mounting table so as to be openable and closable. Is provided. For this reason, some image processing apparatuses not only detect the size of the original placed on the original placing table from the reading results of the open state and the closed state of the platen cover (for example, see Japanese Unexamined Patent Application Publication No. Japanese Patent Application Laid-Open No. 204909/204), there is also a configuration in which it is determined from the density difference between the inside and outside of a document in each state whether or not the document on the document placing table is a translucent document. 224635).

[0005]

However, in the above-mentioned conventional image processing apparatus, in order to reduce or eliminate occurrence of show-through when a document having a high light transmittance is to be read, the following is required. The problems described may occur.

For example, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 5-56257, to reduce or eliminate show-through,
Since a dedicated sensor for detecting the paper quality of the document is required, the configuration of the apparatus becomes complicated and the cost increases. Further, for example, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 6-62216, it is necessary to read both sides of a document in order to determine the amount of show-through, so that much processing time is required. That is, it is difficult to realize quick processing, and as a result, the time from pressing of the copy start button to image output (first copy output time; hereinafter, abbreviated as “FCOT”) is greatly affected.

Further, an image processing apparatus for removing the background (for example, Japanese Patent Application Laid-Open Nos. Hei 7-273995 and Hei 7-322)
In Japanese Patent Application Laid-Open No. 069 and Japanese Patent Application Laid-Open No. 7-75952, the occurrence of show-through is reduced or eliminated by setting a large amount of background removal, so that a document with low light transmittance (show-through does not occur). Even for thick originals, etc., the background removal amount is uniformly increased. Therefore, when show-through does not occur, useless processing is performed, and F
In addition to the possibility of affecting the COT, there is a possibility that another problem such as reproduction of a pattern highlight may be caused.

In the apparatus disclosed in Japanese Patent Laid-Open No. Hei 10-224635, for example, the original on the original table is translucent based on the density difference between the inside and the outside of the original when the platen cover is open and closed. Since it is determined whether the document is a document or not, it is suitable for translucent documents with relatively dark background such as tracing paper, but for documents with almost white background. Is not preferred. That is, since it is determined whether or not the document is a translucent document based on the density difference between the inside and the outside of the document, the show-through of a general document having a slightly high light transmittance and a substantially white background density is removed. Not something.

Therefore, the present invention provides an image processing apparatus that can read a white paper document that is generally widely used without complicating the apparatus configuration and also reducing the FCO.
It is an object of the present invention to provide an image processing apparatus capable of removing show-through without significantly affecting T.

[0010]

According to the present invention, there is provided an image processing apparatus devised to achieve the above-mentioned object, comprising: a document table on which a document to be read is placed; and a document on the document table. A cover that covers the mounting surface so as to be openable and closable, image input means for irradiating the original on the original mounting table with light and obtaining image information about the original from the reflected light, and when the cover is closed Transmitting the transmittance information relating to the transmittance of the document on the document table from the image information obtained by the image input means and the image information obtained by the image input means when the cover is not closed. Information acquisition means.

According to the image processing apparatus having the above-described configuration, for example, when a document having high light transmittance is placed on the document placing table, even if the cover is closed even at the same position on the document, The image information obtained by the image input means and the image information obtained by the image input means when the cover is not closed are different from each other due to the difference in the amount of reflected light. From this, the transmittance information acquiring unit can acquire the transmittance information of the document on the document table by comparing the image information in each state. Moreover, since the transmittance information is based on image information obtained from a document on the document table, the transmittance when read by the image input means is independent of the type (color density, etc.) of the document. It will be reflected. Therefore, in this image processing apparatus, if density correction or the like is performed based on the transmittance information acquired by the transmittance information acquiring means, for example, even when a document having a high light transmittance is placed on the document placing table, It is possible to suppress the occurrence of reflection.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image processing apparatus according to the present invention will be described with reference to the drawings. However, here,
A case where the present invention is applied to a fixed original type digital copying machine will be described as an example. FIG. 1 is a block diagram showing a schematic configuration when the present invention is applied to a digital copying machine.

As shown in FIG. 1, this digital copying machine has an image input terminal (Image Input Terminal; hereinafter, referred to as "IIT") 1, a control unit 2, a closing data holding unit 2a,
After closing, the data holding unit 2b, the image processing unit 3, the background detection unit 4, the background removal unit 5, and the image output unit (Image Output unit)
Terminal; hereinafter referred to as “IOT” 6 and CPU (Cent
ral Processing Unit) 7.
Hereinafter, these components will be described in order.

The IIT 1 is for obtaining image information optically from a fixed document. Here, the IIT 1 will be described in detail. FIG. 2 is an explanatory diagram illustrating a schematic configuration of the IIT 1.

As shown in FIG. 2, the IIT 1 includes a platen glass 11 on which a document A to be read is placed,
A platen cover 12 that opens and closes the original placing surface side of the platen glass 11; a scanner unit 13 that irradiates the original A on the platen glass 11 with light and obtains image information on the original A from the reflected light; , Is provided.

Of these, the scanner unit 13 includes carriages 13a and 13b which can move in the sub-scanning direction along the platen glass 11, and a document A on the platen glass 11 by irradiation of a lamp 13c mounted on the carriage 13a. A lens 13d for condensing the obtained reflected light, and a CCD (Charge) for receiving the condensed reflected light and performing photoelectric conversion
Coupled Device) sensor 13e.
It is assumed that the carriages 13a and 13b are located at predetermined home positions during non-scanning. As the home position, for example, a position where at least one line in the main scanning direction can be read from a document A placed at a predetermined position on the platen glass 11 is considered.

The IIT 1 further includes a platen cover 1
An opening / closing sensor (not shown) for detecting the opening / closing state of No. 2 is provided. That is, in the IIT 1, the open / close sensor can detect whether the platen cover 12 is closed or the platen cover 12 is almost closed (half-opened). It is conceivable that this open / close sensor is realized by, for example, a photosensor or a microswitch whose signal output state changes according to the open / close angle of the platen cover 12.

It should be noted that the IIT 1 may correspond to not only a fixed document but also a document moving on the platen glass 11. That is, the platen glass 11
Automatic Document Feeder (Automatic Document Feeder)
A document feeder may be provided in association with the platen cover 12.

In FIG. 1, the control unit 2 comprises a processor or the like having a predetermined processing function.
Performs the pre-processing necessary for the scanner unit 13 to obtain image information. The preprocessing performed by the control unit 2 includes, for example, detecting the size of the document A placed on the platen glass 11 and acquiring transmittance information described in detail later.

The closing data holding unit 2a and the closed data holding unit 2b are each composed of a memory (RAM or the like) having a capacity for storing image information of at least one line in the main scanning direction. As will be described later, the control unit 2 is used when performing the preprocessing.

The image processing section 3 performs predetermined image processing such as A / D conversion on the image information obtained by the IIT 1.

The background detection unit 4 reads the original based on the image information obtained by the IIT 1 so as to obtain high image quality even when the original having a different background density is to be read. This is for detecting the background density of a scanned document. Note that the background detection unit 4 detects the background density in the same manner as the conventional one, and a detailed description thereof will be omitted here.

The background removal section 5 performs background removal processing on the image information obtained by the IIT 1. However, the background removal unit 5 performs the background removal processing in accordance with the transmittance information acquired by the control unit 2 and the detection result by the background detection unit 4 as described in detail later.

The image processing unit 3, the background detection unit 4, and the background removal unit 5 are realized by a processor or the like having a predetermined processing function.

The IOT 6 includes a printer engine and the like. The IOT 6 converts the image information after the data correction processing in the background removing unit 5 into a visible image on an output sheet by using a well-known electrophotographic technique. Is output.

The CPU 7 functions as a central processing unit (central processor) for controlling the operation of each unit described above.

Next, a description will be given of an example of a processing operation when the image information obtained by the IIT 1 is output by the IOT 6, that is, an example of a processing operation when the copying operation is performed in the digital copying machine having the above-described configuration.

In this digital copying machine, when performing a copying operation, first, a user places an original A to be read in a prescribed position on the platen glass 11 (for example, to make one corner of the original A a corner of the platen glass 11). (The aligned position), and then the platen cover 12 is closed.

At this time, in the IIT 1, the open / close sensor detects the open / close state of the platen cover 12. That is, when the platen cover 12 is about to be closed, this is detected by the open / close sensor, and a platen cover state signal (hereinafter referred to as “closed signal”) to that effect is output from the open / close sensor to the control unit 2. .

Upon receiving the closing signal, the control unit 2
For the scanner unit 13 of the IIT 1, the carriage 13
In the state where a and 13b are at the home position, an instruction is given to read one line of image information from the original A on the platen glass 11 in the main scanning direction. However, the reading from the document A may be n lines (n is a natural number of 2 or more) lines from the home position instead of one line. When the scanner unit 13 reads in accordance with this instruction, the control unit 2 converts the image information of at least one line in the main scanning direction obtained by the reading into
The data is sent to the closing data holding unit 2a and stored in the closing data holding unit 2a.

After that, the platen cover 1 is
When the cover 2 is completely closed, in the IIT 1, this is detected by the open / close sensor, and a platen cover state signal (hereinafter, referred to as a “post-close signal”) to that effect is output from the open / close sensor to the control unit 2.

Upon receiving the signal after closing, the control unit 2
Again, the scanner unit 13 of the IIT 1 is instructed to read one line or n lines in the main scanning direction on the home position, that is, to read image information of the same line as in the case of the closing signal. Then, in accordance with this instruction, the image information for at least one line in the main scanning direction obtained by the scanner unit 13 is sent to the data holding unit 2b after closing, and is stored in the data holding unit 2b after closing.

Thus, the closing data holding unit 2
When the image information for at least one line in the main scanning direction is stored in both the data storage unit 2a and the closed data holding unit 2b, the control unit 2 subsequently performs necessary operations based on the image information stored in each of them. Pre-processing is performed according to.

First, as a preprocessing, the control unit 2 searches for a portion corresponding to the edge of the document A based on the image information stored in each of them, and detects the size of the document A from the result. Further, the control unit 2 acquires the transmittance information of the document A based on the image information stored in each of them.

Here, the acquisition of the transmittance information will be described in detail. The transmittance information is information relating to the light transmittance of the document A placed on the platen glass 11 and is used to specify the degree of the possibility of show-through when the document A is read. Information. Therefore, the transmittance information may be information corresponding to the light transmittance itself of the document A or information approximating the light transmittance as long as it can specify whether or not show-through can occur. You may.

The control unit 2 receives such transmittance information.
Of the image information stored in the closed data holding unit 2a and the closed data holding unit 2b, the image information is obtained by comparing the image information of the portion corresponding to the document A (the portion within the edge). This is because, for example, when a document having a high light transmittance and easily showing off is placed on the platen glass 11, the amount of light reflected from the document greatly differs depending on the open / close state of the platen cover 12. This is because an original having a low rate and hardly showing off is not affected by the open / closed state of the platen cover 12. That is, the control unit 2 compares the image information obtained from the original A with the platen cover 12 open and the image information obtained from the original A with the platen cover 12 closed, thereby obtaining the original A Get the transmittance information of

More specifically, the control unit 2 compares the minimum density value between the open state and the closed state of the platen cover 12 using the information regarding the density of the image information to be compared, thereby obtaining the transmittance information. To get. This eliminates the influence of the image drawn on the original A, and the platen cover 12
By comparing the background density of the document A in the open state and the closed state of the document A, the original light transmittance of the paper quality of the document A is correctly reflected in the result of the acquisition of the transmittance information.

More specifically, the control unit 2 obtains the transmittance information by any of the methods described below. For example, among the image information in the closing data holding unit 2a, the control unit 2 determines the density of the image information corresponding to the document A (the part within the edge) from the read data value of each pixel constituting the image information. A level is extracted, a minimum value is obtained from the extraction result, and this is defined as a minimum density value in a closed state (hereinafter referred to as an “OPEN-MIN value”). Similarly, for the image information in the closed data storage unit 2b, the minimum density value (hereinafter referred to as “CL
OSE-MIN value). And these OPEN-M
The difference between the IN value and the CLOSE-MIN value is calculated, and the calculation result is used as the value of the transmittance information.

Further, for example, the control unit 2 determines a predetermined range (original A) of the image information in the closing data holding unit 2a.
The minimum value of the density level within one certain area above is obtained, and this is defined as the OPEN-MIN value. Also, after closing, the data holding unit 2b
The CLOSE-MIN value is calculated from the same range for the image information in the box. Then, the difference between the OPEN-MIN value and the CLOSE-MIN value is calculated, and the calculation result is used as the value of the transmittance information.

Further, for example, the control unit 2 determines a predetermined range (document A) of the image information in the closing data holding unit 2a.
The average value of the density level in a certain area above) is obtained,
The average value is taken as the OPEN-MIN value. In addition, the CLOSE-MIN value is similarly obtained from the same range for the image information in the data holding unit 2b after closing. And these OPEN-MIN
The difference between the value and the CLOSE-MIN value is calculated, and the calculation result is used as the value of the transmittance information.

For example, the control unit 2 stores the image information of the portion corresponding to the document A (the portion within the edge) among the image information in the closing data holding unit 2a into a plurality of (first to i-th) images set in advance. Divide into blocks). Then, the maximum value of the density level is obtained for each block, the minimum value between the maximum values of each block is obtained, and this is
Use the EN-MIN value. In addition, the CLOSE-MIN value is similarly obtained for the image information in the data holding unit 2b after closing. Then, the difference between the OPEN-MIN value and the CLOSE-MIN value is calculated, and the calculation result is used as the value of the transmittance information.

Further, for example, the control unit 2 may arbitrarily combine the above-mentioned methods (1) to (4) to set the OPEN-MIN value and the CLOSE-MI
The N value is determined, and the difference between them is defined as the value of the transmittance information.

Here, in any of the above-mentioned methods, the document A is moved between when the platen cover 12 is closed and after the platen cover 12 is closed.
The case where the OPEN-MIN value and the CLOSE-MIN value are obtained from a certain range and the difference between these values is used as the value of the transmittance information has been described. It goes without saying that the values of the transmittance information may be obtained by comparing the density levels.

Although the case where the control unit 2 detects the size of the document A and obtains the transmittance information as the preprocessing has been described, the control unit 2 performs the preprocessing as needed. What should I do? For example, when the document size is separately specified by the user from the operation panel, the control unit 2 may not detect the document size described above. Further, in this case, if the control unit 2 acquires the transmittance information by the above-described method, the reading of the image information by the IIT 1 (when the platen cover 12 is closed and after it is closed) is performed. It is also conceivable to perform the process only on a necessary portion, not at least for one line in the main scanning direction.

When the transmittance information is obtained as described above, subsequently, the control unit 2 sets the value of the obtained transmittance information to
In comparison with a predetermined threshold value (hereinafter referred to as “TH1”),
It is determined whether or not there is a risk of show-through when reading the document A. For example, if the value of the transmittance information is equal to or less than TH1, the control unit 2 determines that the light transmittance of the document A is low because the reading result of the document A is not affected by the open / close state of the platen cover 12. Judge that show-through does not occur. If the value of the transmittance information is greater than TH1, the control unit 2 determines that the light transmittance of the document A is high because the reading result of the document A is affected by the open / close state of the platen cover 12. Judge that there is a possibility of being reflected. It is assumed that TH1 is set in advance based on a general rule of thumb.

Then, the control unit 2 determines the value of the transmittance information and T
The results of comparison with H1 are combined with the results of other pre-processing,
Notify U7.

After that, when the user who sets the original A on the platen glass 11 presses the copy start button on the operation panel and instructs the start of the copy operation, the CPU 7 instructs the scanner unit 13 of the IIT 1 to
An instruction is given to read image information (main scan) for the entire area of the document A. Further, the CPU 7
Gives an instruction to each of the image processing unit 3, the background detection unit 4, and the background removal unit 5 to perform processing on the image information obtained by the main scan.

However, at this time, the CPU 7 sets the contents of the instruction to the value of the transmittance information notified from the control unit 2 and TH.
According to the result of comparison with No. 1, the difference is made as follows.

For example, when the value of the transmittance information is equal to or less than TH1, the show-through does not occur with respect to the original A.
The PU 7 instructs a so-called real-time AE (auto-explosure) in which the background detection unit 4 and the background removal unit 5 perform background removal processing on the image information while reading the image information with the scanner unit 13. Thereby, the background detection unit 4 detects the background density for each line in the main scanning direction for the image information obtained by the main scan. Further, the background removal unit 5 performs the background removal processing for each line in the main scanning direction based on the background density value detected by the background detection unit 4.

On the other hand, if the value of the transmittance information is larger than TH1, for example, there is a possibility of show-through, so that the CPU 7
Is different from the above-described case in that the background removal processing is performed by the background removal unit 5 while considering a predetermined threshold value (hereinafter referred to as “TH2”) in addition to the detection result of the background density by the background detection unit 4. Is performed. TH2 is a value suitable for removing show-through, and is set in advance based on a general rule of thumb.

More specifically, when the value of the transmittance information is greater than TH1, the background removing unit 5 firstly receives the background density value detected by the background detecting unit 4 and TH2 in accordance with an instruction from the CPU 7.
Compare with As a result of this comparison, if the background density value is equal to or higher than TH2, show-through can be sufficiently removed by the background removal processing based on the background density value. Therefore, the background removal processing is performed based on the background density value. However, the background density value is TH
If it is smaller than 2, there is a possibility that show-through cannot be removed even if the background removal processing is performed based on the background density value.
The background removal processing is performed based on TH2 instead of the background density value.

More specifically, if the value of the transmittance information is equal to or less than TH1 (when the document is outside the predetermined transmittance), FIG.
As shown in (2), the background removal density removed by the background removal unit 5 changes up to the background density of the document A (that is, irrespective of TH2), and then reaches the background density determination position. If the value of the rate information is larger than TH1 (if the document is within the predetermined transmittance) and the background density value is TH
If it is smaller than 2, as shown in FIG. 3B, the background removal density does not fall below TH2 and reaches the background density determination position as it is. In addition, even if the value of the transmittance information is larger than TH1, if the background density value is equal to or more than TH2, the removal amount at the time of reaching the background density determination position is used. In the case of FIG. Since the background removal density is lower than TH2, TH2 is employed.

The background removal unit 5 sets a large amount of background removal (for example, background density value + offset value, TH2 + offset value, etc.) in order to realize higher image quality, and Processing may be performed.

When the background removal unit 5 performs the background removal processing on the image information obtained by the main scan, the CPU 7 then outputs the image information after the background removal processing is performed to the IOT 6. Give instructions to do. Thus, the IOT 6 outputs the image information obtained by the main scan as a visible image on an output sheet.

As described above, in the digital copying machine according to the present embodiment, the image information obtained from the original A when the platen cover 12 is open and the closed state of the platen cover 12 By comparing the image information obtained from the document A with the image information, the transmittance information of the document A is obtained.

Therefore, a dedicated sensor or the like is not required for acquiring the transmittance information, and the apparatus configuration does not become complicated and the cost does not increase. Further, since it is not necessary to read both sides of the document A to be read in advance, and since the transmittance information is obtained in the pre-processing before the copy start button is pressed, a quick processing can be realized, and the FCOT is large. There is no impact.

Further, the obtained transmittance information is the same as the original A
Since it is based on the image information of a substantial part, the reading state of the scanner unit 13 is reflected regardless of the type of the document A. That is, regardless of the type of the document A to be read, whether or not show-through can occur when the document is actually read by the scanner unit 13 can be determined.

In particular, in the digital copying machine of the present embodiment, as in the second aspect of the present invention, the transmittance information is obtained by using the information regarding the density in the image information. That is, in acquiring the transmittance information, the minimum density value between the open state and the closed state of the platen cover 12 is compared.

Therefore, the acquired transmittance information indicates that the original A to be read is any type of paper.
The information on the original light transmittance of the document A is correctly reflected. That is, for example, unlike a case where it is determined whether or not a document is a translucent document based on a density difference between the inside and the outside of the document, a translucent document having a relatively dark background density such as tracing paper or light It is possible to accurately specify whether or not show-through can occur even in a document whose background density is almost white despite its high transmittance.

In the digital copying machine according to the present embodiment, the background removal unit 5 performs the background removal processing at the time of the main scan according to the transmittance information acquired by the control unit 2 as described in the third aspect. At the same time, the IOT 6 outputs the image information after the background removal processing on output paper.

Therefore, if a copying operation is performed using this digital copying machine, even if the light transmittance of the original A is high, the occurrence of show-through can be suppressed by the background removal processing in the background removal unit 5. Become like In addition, when the light transmittance of the document A is low, it is possible to prevent unnecessary processing, so that it does not greatly affect the FCOT and the amount of background removal is uniformly increased. As described above, there is no possibility of causing another problem such as the reproduction of the pattern highlight.

Further, in the digital copying machine according to the present embodiment, the background detecting section 4 detects the background density of the document A, the detection result of the background density and the control section 2 as described in the fourth aspect of the present invention. The background removal unit 5 performs background removal processing based on both the acquired transmittance information and the background information.

Therefore, in this digital copying machine, even if the light transmittance of the original A is high, if the show-through can be sufficiently removed by the background removal processing based on the background density value, the background density value can be reduced. The background removal processing can be performed based on the preset TH2 if there is a possibility that the show-through cannot be removed even if the background removal processing is performed based on the background density value. Becomes That is,
While eliminating unnecessary processing that may affect FCOT,
The generation of show-through can be reliably suppressed, and the provision of a high-quality output image can be realized.

As a result, the digital copying machine is suitable for use on a document whose background density is almost white. That is, by performing the background removal processing based on both the detection result of the background density and the transmittance information, for example, a document having a substantially white background density even when the light transmittance is high, the show-through in the related art is not possible. Even if the removal is difficult, the occurrence of show-through can be surely suppressed.

In the present embodiment, the case where the control unit 2 acquires the transmittance information at the time of the preprocessing has been described.
The present invention is not limited to this. That is, the transmittance information may be obtained prior to the main scan as in the case of the present embodiment, or may be obtained together with the image information for output at the time of the main scan.

In this embodiment, the case has been described where the IOT 6 outputs the image information read by the main scan again after acquiring the transmittance information. However, the present invention is not limited to this. The IOT 6 may output the image information used for obtaining the transmittance information as it is.

Further, in the present embodiment, the case where the present invention is applied to a digital copying machine has been described as an example, but the present invention is not limited to this. In other words, if an image processing apparatus has a function of optically obtaining image information from a fixed document and performing image processing on the image information, other image processing apparatuses (for example, a scanner apparatus and a printer apparatus). It is needless to say that the present invention is also applicable to a system including

[0068]

As described above, according to the image processing apparatus of the present invention, the image information obtained from the original when the cover for covering the original is closed, and the original when the cover is not closed. By comparing the original information with the image information obtained from the original, the transmittance information of the document is obtained. Therefore, a dedicated sensor or the like is not required to acquire the transmittance information, so that the apparatus configuration does not become complicated or the cost increases. In addition, since it is not necessary to read both sides of the original document in advance, it is possible to realize quick processing, and the FCOT is not significantly affected. Furthermore, since the obtained transmittance information is based on image information obtained from the original, information on the original light transmittance of the original paper quality is correctly reflected regardless of the paper type of the original. Becomes Therefore, in this image processing apparatus, if the density correction or the like is performed on the read image information based on the transmittance information, for example, the original has a relatively high light transmittance and is generally a white paper original. , The occurrence of show-through can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall schematic configuration in an example of an embodiment of an image processing apparatus according to the present invention.

FIG. 2 is an explanatory diagram illustrating a schematic configuration of a main part (IIT) in an example of an embodiment of an image processing apparatus according to the present invention.

FIGS. 3A and 3B are explanatory diagrams illustrating a specific example of the background removal density when the background removal processing is performed, where FIG. 3A illustrates an example in which the value of transmittance information is outside a predetermined range, and FIG. It is a figure showing an example when the value of rate information is within predetermined.

[Description of Signs] 1 ... Image input unit (IIT), 2 ... Control unit, 2a ... Closed data holding unit, 2b ... Closed data holding unit, 4 ... Background detection unit, 5 ... Background removal unit, 6 ... Image output unit (IO
T), 7 CPU, 11 platen glass, 12 platen cover, 13 scanner unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 DA25 DB01 DB02 DE02 5B047 AA01 AB02 BA02 CB22 DA03 DB06 DC06 5C062 AB02 AB17 AB30 AC21 AC61 AC65 AD02 BA00 5C077 LL02 MM20 PP25 PP43 PQ20 SS01 TT06

Claims (4)

[Claims] An original placing table on which an original to be read is placed; a cover for opening and closing the original placing surface of the original placing table; and a light source for irradiating the original on the original placing table with light. Image input means for obtaining image information about the original from the reflected light, image information obtained by the image input means when the cover is closed, and image input when the cover is not closed. An image processing apparatus comprising: transmittance information acquiring means for acquiring, from the image information obtained by the means, transmittance information relating to the transmittance of the document on the document mounting table. 2. The image processing apparatus according to claim 1, wherein the transmittance information obtaining unit obtains the transmittance information by using information on a density in the image information obtained by the image input unit. apparatus. 3. An image processing means for performing image processing according to the transmittance information obtained by said transmittance information obtaining means on image information obtained by said image input means when said cover is closed. The image processing apparatus according to claim 1, further comprising: an image output unit that outputs, as a visible image, image information after image processing performed by the image processing unit. And a detecting means for detecting a background density of the document on the document mounting table, wherein the image processing means includes: a transmission information acquired by the transmittance information acquiring means; and a background detected by the detection means. 4. The image processing apparatus according to claim 3, wherein the image processing is performed according to the density.