JP3928285B2 - Image processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus having a function of optically obtaining image information from a fixed document and performing image processing on the image information, such as a document fixing type copying machine. .
[0002]
[Prior art]
In general, an image processing apparatus such as a copying machine optically reads image information, and therefore reads a document on which images are recorded on both sides of a sheet having a high light transmittance (such as a very thin sheet or tracing paper). As a target, even when only one side of the document is read, 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. In order to reduce or eliminate the occurrence of such show-through, conventionally, some image processing apparatuses detect the paper quality of a document to be read by a dedicated sensor, and perform density correction according to the detection result ( For example, refer to Japanese Patent Laid-Open No. 5-56257), and there is a structure in which the amount of show-through is obtained from the reading result on both sides of the document and the show-through is removed (see, for example, Japanese Patent Laid-Open No. ).
[0003]
Furthermore, in the image processing apparatus, in addition to originals using white paper, originals having different color densities (hereinafter referred to as “background density”) such as newspapers and colored papers may be read. For this reason, the image processing apparatus detects the background density of the original to be read and responds to the detection result so that an optimum output can be obtained even when the original is to be read. In some cases, the tone correction (hereinafter, this correction is referred to as “background removal”) is performed (see, for example, Japanese Patent Laid-Open Nos. 7-27395, 7-322069, and 7-74952). In the case of 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 large.
[0004]
An image processing apparatus that obtains image information from a fixed document usually includes a document placement table on which a document to be read is placed, and a platen cover that covers the document placement table so that the document placement table can be opened and closed. Yes. For this reason, in some image processing apparatuses, in addition to detecting the size of the document placed on the document placement table from the reading results of the platen cover opened and closed (for example, Japanese Patent Laid-Open No. Hei 8- In some cases, it is determined whether or not the document on the document table is a translucent document based on the density difference between the inside and outside of the document in each state (for example, Japanese Patent Laid-Open No. Hei 10). No. -224635).
[0005]
[Problems to be solved by the invention]
However, in the conventional image processing apparatus described above, when a document having a high light transmittance is to be read, the following problems arise in reducing or eliminating the occurrence of show-through. there is a possibility.
[0006]
For example, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 5-56257, a dedicated sensor for detecting the paper quality of the document is required for reducing or eliminating the show-through, resulting in an increase in complexity and cost of the apparatus. It will end up. Further, for example, in the apparatus disclosed in Japanese Patent Laid-Open No. 6-62216, it is necessary to read both sides of the document in order to obtain the amount of show-through, which requires a lot of processing time. That is, it is difficult to realize a rapid process, 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.
[0007]
For image processing apparatuses that perform background removal (see, for example, Japanese Patent Application Laid-Open Nos. 7-27395, 7-322069, and 7-74952), the background removal amount is set to a large value. Since the occurrence of reflection is reduced or eliminated, the background removal amount is uniformly increased even for a document with low light transmittance (such as a thick document with no show-through). For this reason, when show-through does not occur, useless processing is performed, which may affect the FCOT, and may cause other problems such as reproduction of pattern highlights.
[0008]
For example, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 10-224635, the document on the document table is a translucent document due to the density difference between the inside and outside of the document in the open state and the closed state of the platen cover. Therefore, it is suitable for a semi-transparent document having a relatively high background density such as tracing paper, but suitable for a document having a substantially white background density. It cannot be said. In other words, since it is determined whether or not the document is a semi-transparent document from the density difference between the inside and 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. It is not a thing.
[0009]
Therefore, according to the present invention, even when a document to be read is a white paper document that is generally widely used, the configuration of the apparatus is not complicated, and the FCOT may be greatly affected. An object of the present invention is to provide an image processing apparatus capable of removing show-through.
[0010]
[Means for Solving the Problems]
The present invention is an image processing apparatus devised to achieve the above object, and covers a document placing table on which a document to be read is placed and a document placing surface side of the document placing table so as to be openable and closable. The cover and the document on the document table are irradiated with light, and the reflected light Concentration information Obtained by the image input means when the cover is closed Density information about the original and Obtained by the image input means when the cover is not closed By comparison with density information about the manuscript A transmittance information acquiring means for acquiring transmittance information relating to the transmittance of the document on the document table; Image processing means for performing image processing according to the transmittance; It is characterized by providing.
[0011]
According to the image processing apparatus having the above configuration, for example, when a document having a high light transmittance is placed on the document placing table, an image is input when the cover is closed even at the same position on the document. Obtained by means Density information about the document And can be obtained by the image input means when the cover is not closed. Density information about the document Are different from each other due to the difference in the amount of reflected light. From this, the transmittance information acquisition means in each state Concentration information Thus, it is possible to acquire the transmittance information about the document on the document table. Moreover, the transmittance information was obtained from the document on the document table. Concentration information Therefore, regardless of the type of document (color density, etc.), the transmittance when read by the image input means is 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 unit, for example, even when a document with high light transmittance is placed on the document placing table, It is possible to suppress the occurrence of reflection.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The image processing apparatus according to the present invention will be described below with reference to the drawings. However, here, a case where the present invention is applied to a document fixing 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.
[0013]
As shown in the figure, this digital copying machine includes an image input unit (Image Input Terminal; hereinafter referred to as “IIT”) 1, a control unit 2, a closing data holding unit 2a, and a closed data holding unit 2b. An image processing unit 3, a background detection unit 4, a background removal unit 5, an image output unit (hereinafter referred to as “IOT”) 6, and a CPU (Central Processing Unit) 7. It is configured. Hereinafter, each of these units will be described in order.
[0014]
IIT1 optically obtains image information from a fixed document. Here, this IIT1 will be described in detail. FIG. 2 is an explanatory diagram showing a schematic configuration of the IIT 1.
[0015]
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 covers the platen glass 11 so that it can be opened and closed, and a platen glass 11 on the platen glass 11. A scanner unit 13 that irradiates the original A with light and obtains image information about the original A from the reflected light.
[0016]
Of these, the scanner unit 13 includes a carriage 13a, 13b that can move in the sub-scanning direction along the platen glass 11, and a reflection obtained from the original A on the platen glass 11 by irradiation of a lamp 13c mounted on the carriage 13a. A lens 13d that collects light and a CCD (Charge Coupled Device) sensor 13e that receives the collected reflected light and performs photoelectric conversion are provided. The carriages 13a and 13b are assumed to be positioned at a predetermined home position during non-scanning. As the home position, for example, a position where at least one line in the main scanning direction can be read with respect to the document A placed at a specified position on the platen glass 11 can be considered.
[0017]
Further, the IIT 1 is provided with an open / close sensor (not shown) for detecting the open / close state of the platen cover 12. That is, in the IIT 1, it is possible to detect whether the platen cover 12 is in a closed state or whether the platen cover 12 is in a closed state (half-opened state) by this open / close sensor. This open / close sensor may be realized by, for example, a photo sensor or a micro switch whose signal output state changes according to the open / close angle of the platen cover 12.
[0018]
Note that the IIT 1 may support not only a fixed document but also a document moving on the platen glass 11. That is, an automatic document feeder that moves the document A on the platen glass 11 may be provided along with the platen cover 12.
[0019]
In FIG. 1, the control unit 2 includes a processor having a predetermined processing function, and performs preprocessing necessary for the scanner unit 13 of the IIT 1 to obtain image information. Pre-processing performed by the control unit 2 includes, for example, size detection of the document A placed on the platen glass 11 and acquisition of transmittance information described later in detail.
[0020]
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 for at least one line in the main scanning direction, and will be described in detail later. The control unit 2 is used for preprocessing.
[0021]
The image processing unit 3 performs predetermined image processing such as A / D conversion on the image information obtained by the IIT 1.
[0022]
The background detection unit 4 uses the image information obtained by the IIT 1 to obtain a high quality image even when a document having a different background density is to be read. This is for detecting the background density. Since the background detection unit 4 detects the background density in the same manner as the conventional one, detailed description thereof is omitted here.
[0023]
The background removal unit 5 performs background removal processing on the image information obtained by IIT1. However, the background removal unit 5 performs the background removal process according to the transmittance information acquired by the control unit 2 and the detection result of the background detection unit 4, as will be described in detail later.
[0024]
Note that 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.
[0025]
The IOT 6 includes a printer engine and the like, and outputs the image information after the data correction processing in the background removal unit 5 is performed as a visible image on output paper using a known electrophotographic technique. Is.
[0026]
The CPU 7 functions as a central processing unit (central processor) that controls the operation of each unit described above.
[0027]
Next, in the digital copying machine configured as described above, an example of processing operation when image information obtained by IIT1 is output by IOT6, that is, an example of processing operation when performing a copying operation will be described.
[0028]
In this digital copying machine, when a copying operation is performed, first, a user places an original A to be read on a specified position on the platen glass 11 (for example, a position where one corner of the original A is aligned with one corner on the platen glass 11). ) And then the platen cover 12 is closed.
[0029]
At this time, in IIT1, the open / close sensor detects the open / closed state of the platen cover 12. That is, when the platen cover 12 is in the closing state, this is detected by the opening / closing sensor, and a platen cover state signal (hereinafter referred to as “closing signal”) to that effect is output from the opening / closing sensor to the control unit 2. .
[0030]
When the closing signal is received, the control unit 2 receives image information for one line in the main scanning direction from the document A on the platen glass 11 with the carriages 13a and 13b positioned at the home position with respect to the scanner unit 13 of the IIT1. Give instructions to read. However, the reading from the document A may be performed not for one line but for n lines (n is a natural number of 2 or more) from the home position. When the scanner unit 13 performs reading according to this instruction, the control unit 2 sends image information for at least one line in the main scanning direction obtained by the reading to the closing data holding unit 2a, and holds the closing data. It is stored in the part 2a.
[0031]
After that, when the platen cover 12 is completely closed by the user, in the IIT1, this is detected by the open / close sensor, and a platen cover state signal (hereinafter referred to as a “closed signal”) is sent from the open / close sensor to the control unit. 2 is output.
[0032]
When receiving the signal after closing, the control unit 2 again sends the image information of one line or n lines in the main scanning direction on the home position to the scanner unit 13 of the IIT1, that is, the same line image information as in the case of the closing signal. Give instructions to read. Then, according to this instruction, 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 being closed, and stored in the data holding unit 2b after being closed.
[0033]
In this way, when image information for at least one line in the main scanning direction is stored in both the closing data holding unit 2a and the closed data holding unit 2b, the control unit 2 subsequently includes Based on the stored image information, preprocessing is performed as necessary.
[0034]
First, as a pre-process, the control unit 2 searches for a portion corresponding to the edge of the document A based on the image information stored in each, and detects the size of the document A from the result. Furthermore, the control unit 2 acquires transmittance information for the document A based on the image information stored in each.
[0035]
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 to which the show-through may occur when the document A is read. Information. Therefore, the transmittance information is information corresponding to the light transmittance itself of the document A or information that approximates the light transmittance as long as it can specify whether or not show-through can occur. May be.
[0036]
The control unit 2 obtains such transmittance information from the image information stored in the closing data holding unit 2a and the closed data holding unit 2b, corresponding to the portion corresponding to the original A (the portion within the edge). Obtain by comparing each. This is because, for example, when a document having a high light transmittance and easy to show through is placed on the platen glass 11, the amount of light reflected from the document varies greatly depending on the open / closed state of the platen cover 12, but the light transmission This is because if the document is low in rate and difficult to show through, it is not affected by the open / close state of the platen cover 12. That is, the control unit 2 compares the image information obtained from the document A with the platen cover 12 in the open state and the image information obtained from the document A with the platen cover 12 in the closed state. Get the transmittance information.
[0037]
More specifically, the control unit 2 uses the information regarding the density of the image information to be compared, and acquires the transmittance information by comparing the minimum density value between the open state and the closed state of the platen cover 12. . This eliminates the influence of the image drawn on the document A and compares the background density of the document A between the open state and the closed state of the platen cover 12, thereby obtaining the transmission result of the document A as a result of the transmission of the document A. This is to correctly reflect the original light transmittance of the paper quality.
[0038]
Specifically, the control unit 2 acquires the transmittance information by any one of methods (1) to (5) described below.
(1) For example, the control unit 2 reads the image data of each pixel constituting the image information of the image information in the document A corresponding to the document A (portion in the edge) out of the image information in the closing data holding unit 2a. The density level is extracted from the value, the minimum value is obtained from the extraction result, and this is set as the minimum density value in the closed state (hereinafter referred to as “OPEN-MIN value”). Similarly, for the image information in the data holding unit 2b after being closed, a minimum density value (hereinafter referred to as “CLOSE-MIN value”) in the state after being closed is obtained. 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.
[0039]
(2) Further, for example, the control unit 2 obtains the minimum value of the density level in a predetermined range (a certain area on the document A) from the image information in the closing data holding unit 2a, and obtains this value. MIN value. Also, for the image information in the data holding unit 2b after being closed, the CLOSE-MIN value is obtained from the same range. 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.
[0040]
(3) Further, for example, the control unit 2 obtains an average value of density levels in a predetermined range (a certain area on the document A) out of the image information in the closing data holding unit 2a, and the average value is opened. -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 being closed. 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.
[0041]
(4) Further, for example, the control unit 2 sets a plurality of preset image information (first to i) in the image information in the closing data holding unit 2a corresponding to the portion corresponding to the document A (the portion in the edge). )). Then, the maximum value of the density level is obtained for each block, and the minimum value between the maximum values of each block is obtained, and this is set as the OPEN-MIN value. Similarly, the CLOSE-MIN value is obtained for the image information in the data holding unit 2b after being closed. 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.
[0042]
(5) Further, for example, the control unit 2 obtains an OPEN-MIN value and a CLOSE-MIN value by arbitrarily combining the above-described methods (1) to (4), and determines the difference between them as transmittance information. The value of
[0043]
Here, in any of the methods (1) to (5) described above, a predetermined range is taken into consideration when the document A is moved between when the platen cover 12 is closed and after it is closed. In the above description, the OPEN-MIN value and the CLOSE-MIN value are obtained from the above, and the difference between these values is used as the value of the transmittance information. However, the density level at a predetermined location (one pixel) on the document A is Needless to say, the value of the transmittance information may be acquired by comparison.
[0044]
Here, the case where the control unit 2 performs the size detection of the document A and the acquisition of the transmittance information as the preprocessing has been described. However, the control unit 2 may perform these preprocessing as necessary. Good. For example, when the user specifies a document size separately from the operation panel, the control unit 2 may not perform the above-described document size detection. Further, in this case, if the control unit 2 acquires the transmittance information by the method (2) described above, the image information is read by the IIT 1 (when the platen cover 12 is closed and after it is closed). It is also conceivable that the above is performed only for a necessary portion, not at least for one line in the main scanning direction.
[0045]
When the transmittance information is acquired as described above, the control unit 2 compares the value of the acquired transmittance information with a predetermined threshold value (hereinafter referred to as “TH1”), and copies the document A. It is determined whether there is a risk of show-through when read. For example, if the value of the transmittance information is equal to or less than TH1, the control unit 2 has a low light transmittance of the document A because the reading result of the document A is not affected by the open / close state of the platen cover 12. Judge that no show-through occurs. If the value of the transmittance information is greater than TH1, the control unit 2 has a high light transmittance of the document A because the reading result of the document A is affected by the open / close state of the platen cover 12, and the back side. Judge that there is a possibility of reflection. TH1 is set in advance based on a general rule of thumb.
[0046]
Then, the control unit 2 notifies the CPU 7 of the comparison result between the value of the transmittance information and TH1, together with the result of other preprocessing.
[0047]
Thereafter, when the user who sets the document A on the platen glass 11 presses the copy start button on the operation panel and instructs to start the copy operation, the CPU 7 instructs the scanner unit 13 of the IIT 1 to copy the document A. An instruction is given to read (main scan) image information for all areas. Further, the CPU 7 instructs the image processing unit 3, the background detection unit 4, and the background removal unit 5 to perform processing on the image information obtained in the main scan.
[0048]
However, at this time, the CPU 7 makes the instruction content different as follows according to the comparison result between the value of the transmittance information notified from the control unit 2 and TH1.
[0049]
For example, when the value of the transmittance information is equal to or lower than TH1, no show-through occurs with respect to the document A. Therefore, the CPU 7 reads the image information with the scanner unit 13 and reads the background detection unit 4 and the background removal unit 5. Instructs the so-called real-time AE (auto explorer) to perform the background removal processing on the image information. Accordingly, the background detection unit 4 detects the background density for each line in the main scanning direction for the image information obtained in the main scan. Further, the background removal unit 5 performs background removal processing for each line in the main scanning direction based on the background density value detected by the background detection unit 4.
[0050]
On the other hand, for example, when the value of the transmittance information is greater than TH1, there is a possibility of show-through, so that the CPU 7 differs from the above case in addition to the detection result of the background density in the background detection unit 4 in addition to the predetermined result. The background removal unit 5 is caused to perform the background removal process while taking into account the threshold value (hereinafter referred to as “TH2”). This TH2 is a value suitable for removing show-through and is set in advance based on a general rule of thumb.
[0051]
Specifically, when the value of the transmittance information is greater than TH1, the background removal unit 5 first compares the background density value detected by the background detection unit 4 with TH2 in accordance with an instruction from the CPU 7. As a result of this comparison, if the background density value is equal to or higher than TH2, the show-through can be sufficiently removed by the background removal process based on the background density value, and therefore the background removal process is performed based on the background density value. However, if the background density value is smaller than TH2, there is a possibility that the show-through cannot be removed even if the background removal process is performed based on the background density value. Therefore, the background removal process is performed based on TH2 instead of the background density value. Do.
[0052]
Specifically, if the value of the transmittance information is equal to or lower than TH1 (in the case of a document outside the predetermined transmittance), the background removal density removed by the background removal unit 5 as shown in FIG. It changes until the background density of the document A is reached (that is, it is irrelevant to TH2), and then reaches the background density determination position, while the value of the transmittance information is larger than TH1 (in the case of a document within a predetermined transmittance). If the background density value is smaller than TH2, as shown in FIG. 3B, the background removal density does not fall below TH2, but reaches the background density determination position as it is. Even if the value of the transmittance information is greater than TH1, if the background density value is equal to or greater than TH2, the removal amount when the background density determination position is reached is adopted, but in the case of FIG. Since the background removal density is smaller than TH2, TH2 is adopted.
[0053]
Note that the background removal unit 5 performs background removal processing by setting a large amount of background removal (for example, background density value + offset value, TH2 + offset value, etc.) in order to achieve higher image quality. You may do it.
[0054]
When the background removal unit 5 performs the background removal process on the image information obtained by the main scan, the CPU 7 then outputs the image information after the background removal process is performed to the IOT 6. Give instructions. As a result, the IOT 6 outputs the image information obtained by the main scan as a visible image on the output paper.
[0055]
As described above, in the digital copying machine of the present embodiment, as in the invention described in claim 1, the image information obtained from the document A when the platen cover 12 is open and the document A when the platen cover 12 is closed. The transmittance information for the document A is acquired by comparing with the image information obtained from the above.
[0056]
Therefore, when acquiring the transmittance information, a dedicated sensor or the like is not required, and the apparatus configuration is not complicated and the cost is not increased. Further, since it is not necessary to read both sides of the original A to be read in advance and the transmittance information is acquired by the pre-processing before the copy start button is pressed, it is possible to realize a quick process, which is very important for the FCOT. There is no impact.
[0057]
Further, since the acquired transmittance information is based on the image information of the portion corresponding to the document A, the reading state of the scanner unit 13 is reflected regardless of the paper type of the document A. That is, it becomes possible to know whether or not show-through can occur when the original document A to be read is any type of paper when it is actually read by the scanner unit 13.
[0058]
In particular, in the digital copying machine according to the present embodiment, as in the invention described in claim 2, the transmittance information is acquired by using information on the density in the image information. That is, when acquiring the transmittance information, the minimum density values in the open state and the closed state of the platen cover 12 are compared.
[0059]
Therefore, the acquired transmittance information correctly reflects information on the original light transmittance of the paper quality of the document A, regardless of the type of document A to be read. That is, unlike when determining whether a document is a semi-transparent document from the density difference between the inside and outside of the document, for example, even a semi-transparent document having a relatively high background density such as tracing paper or the like, It is possible to accurately specify whether or not show-through can occur even in a document having a high transmittance and a background density of almost white.
[0060]
Further, in the digital copying machine of the present embodiment, as in the invention described in claim 3, the background removal unit 5 performs the background removal processing during the main scan according to the transmittance information acquired by the control unit 2, The IOT 6 outputs the image information after the background removal processing on the output paper.
[0061]
Therefore, if a copying operation is performed using this digital copying machine, the occurrence of show-through can be suppressed by the background removal processing in the background removal unit 5 even when the light transmittance of the document A is high. . In addition, when the light transmittance of the document A is low, it is possible not to perform useless processing. Therefore, when the background removal amount is uniformly increased without greatly affecting the FCOT. As such, there is no possibility of causing other problems such as reproduction of pattern highlights.
[0062]
Furthermore, in the digital copying machine according to the present embodiment, the background detection unit 4 detects the background density of the document A and the detection result of the background density and the control unit 2 acquire the background density as in the invention described in claim 4. Based on both the transmittance information, the background removal unit 5 performs the background removal processing.
[0063]
Therefore, in this digital copying machine, even if the light transmittance of the document A is high, if the show-through can be sufficiently removed by the background removal processing based on the background density value, the digital copying machine is based on the background density value. While the background removal process is performed, if there is a possibility that the show-through cannot be removed even if the background removal process is performed based on the background density value, the background removal process can be performed based on the preset TH2. That is, it is possible to reliably prevent the occurrence of show-through while eliminating unnecessary processing that may affect the FCOT, and to provide a high-quality output image.
[0064]
As a result, this digital copying machine is suitable even when used for a document whose background density is almost white. That is, by performing the background removal process based on both the background density detection result and the transmittance information, the conventional technique does not show the show-through like a manuscript whose background density is almost white even though the light transmittance is high. Even if it is difficult to remove, the occurrence of show-through can be reliably suppressed.
[0065]
In the present embodiment, the case where the control unit 2 acquires the transmittance information during the preprocessing has been described, but the present invention is not limited to this. That is, the transmittance information may be acquired prior to the main scan as in the present embodiment, or may be acquired together with the image information for output during the main scan.
[0066]
In the present embodiment, the case where the IOT 6 outputs the image information read by the main scan again after acquiring the transmittance information has been described. However, the present invention is not limited to this, for example, the transmittance information. The IOT 6 may output the image information used for acquisition of the image as it is.
[0067]
Furthermore, 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. That is, other image processing devices (for example, a scanner device and a printer device) can be used as long as the image processing device has a function of optically obtaining image information from a fixed document and performing image processing on the image information. Needless to say, the present invention can also be applied to a system including
[0068]
【The invention's effect】
As described above, the image processing apparatus of the present invention can be obtained from a document when the cover that covers the document is closed. Concentration information And obtained from the manuscript when the cover is not closed Concentration information And the transmittance information about the document is acquired. For this reason, a dedicated sensor or the like is not required for acquiring the transmittance information, so that the apparatus configuration is not complicated and the cost is not increased. In addition, since it is not necessary to read both sides of the original document in advance, it is possible to realize a quick process without greatly affecting the FCOT. Further, the acquired transmittance information was obtained from the document. Concentration information Therefore, regardless of the paper type of the original, information regarding the original light transmittance of the paper quality of the original is correctly reflected.
Therefore, in this image processing apparatus, if density correction or the like is performed on the read image information based on the transmittance information, for example, the original has a slightly higher light transmittance and is generally widely used. In this case, the occurrence of show-through can be suppressed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall schematic configuration of an example of an embodiment of an image processing apparatus according to the present invention.
FIG. 2 is an explanatory diagram showing a schematic configuration of a main part (IIT) in an example of an embodiment of an image processing apparatus according to the present invention.
FIG. 3 is an explanatory diagram that controls a specific example of a background removal density when a background removal process is performed, in which FIG. 3A is a diagram illustrating an example of a case where the value of transmittance information is not predetermined, and FIG. It is a figure which shows an example in case the value of rate information is in predetermined.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image input part (IIT), 2 ... Control part, 2a ... Closing data holding part, 2b ... Closed data holding part, 4 ... Background detection part, 5 ... Background removal part, 6 ... Image output part (IOT) 7 ... CPU, 11 ... Platen glass, 12 ... Platen cover, 13 ... Scanner section

Claims (3)

A document table on which a document to be read is placed;
A cover that covers the document placement surface side of the document placement table so as to be openable and closable;
Image input means for irradiating light on the document on the document table and obtaining density information about the document from the reflected light;
By comparing the density information about the original obtained by the image input means when the cover is closed with the density information about the original obtained by the image input means when the cover is not closed . a transmission information obtaining means for obtaining transmission information related to the transmittance of the document on the document table,
An image processing apparatus comprising image processing means for performing image processing according to the transmittance . Image output means for outputting the image information after the image processing by the image processing means is performed as a visible image
The image processing apparatus according to claim 1, characterized in that it comprises. A detecting means for detecting the background density of the document on the document table;
The image according to claim 1 or 2 , wherein the image processing means performs image processing according to the transmittance information acquired by the transmittance information acquiring means and the background density detected by the detecting means. Processing equipment.

Images