JP5515604B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus having an image reading function including an image scanner, a digital copying machine, a facsimile machine, a printer, a multifunction machine, and a network file server.

A system has been devised in which character information written on a medium is converted into electronic data by character recognition technology and stored as a database.
In such a system, for example, when character information including an address, an address, and a postal code written in a mail piece is converted into electronic data, the entire image of the mail piece is read, and a pattern by character recognition technology is applied to the whole image. Character information can be converted into electronic data by performing recognition processing.
However, if there is non-character recognition target information such as a background or pattern that is not necessary for character recognition around the character information of the postal matter, if the character information is recognized from the entire postal image, it will be affected by the non-character recognition information. As a result, the accuracy of pattern recognition may be reduced. Therefore, in order to improve the accuracy of pattern recognition, it is desirable to delete information that is not subject to character recognition as much as possible.

Therefore, if the postal item is a fixed format with a predetermined frame such as ruled lines, the entire image of the postal item is read, and the approximate position information containing the character information is calculated based on the fixed format, and the position A partial image including character information is cut out from the entire image based on the information. The extracted partial image is subjected to pattern recognition processing by a character recognition technique to convert character information into electronic data.
Conventionally, a technique of extracting an area formed by oblique lines of paper sheets and recognizing destination information in a window area detected based on the area (for example, refer to Patent Document 1), or an address is described in the window area. The image is read from the medium, the image is divided into small partial areas, the position (edge) where the density of the image changes greatly is detected, the density of edges existing in each partial area is calculated, and the edge density is There has been a technique (see, for example, Patent Document 2) in which an area lower than a threshold is used as a window area and an address is read from an image of the window area.

However, the above-described conventional technique has a problem that it is difficult to capture desired character information unless a medium with a fixed format in which a predetermined frame such as ruled lines is described is used.
Even in a fixed format medium, the user does not always write the character information correctly in the frame, and the image information outside the frame is removed when cutting out the image information necessary for character recognition from the frame. Therefore, there is a problem that it is difficult to capture character information that partly protrudes from the frame.
Further, in the above-described conventional technology, after reading the entire image of the medium, the character recognition target part is identified from the image information, the image information of the character recognition target part is cut out, and the cut image information is extracted. A lot of processing such as character recognition is necessary, and complicated processing to identify the character recognition target part from the entire image of the medium is necessary, which increases the amount of image information data and processing time. There was a problem that.

The present invention has been made in view of the above points, and it is not necessary to use a fixed format when capturing character information described in an area thicker than the periphery on the medium, and is necessary for character recognition. An object of the present invention is to reduce the amount of image information and shorten the processing time for character recognition.

In order to achieve the above object, the present invention provides an image reading means for reading an image of a document, a document conveying means for conveying the document to a reading position of the image reading means, and the document conveyed by the document conveying means. Document thickness detection means for detecting the thickness of the document before reaching the reading position, and the thickness of the entire surface of the document detected by the document thickness detection means before reading the image of the document by the image reading means. a region specifying means for specifying a region thickness than the value obtained by averaging the thickness of the document on the entire surface is large on the basis of the averaged value of, only the specified areas on the document by the image reading means Provided is an image reading apparatus provided with reading control means for reading an image.

In addition, when there are a plurality of areas specified by the area specifying means, it is preferable to provide means for notifying a warning and stopping reading the image of the document.
Further, when there are a plurality of areas specified by the area specifying means, a selection means for selecting an area to be read from each of the areas, and an image of only the selected area on the original by the image reading means. There may be provided means for reading.
In addition, when there are a plurality of regions specified by the region specifying unit and a reference region specifying unit for specifying a reference region for determining an image reading target region on the document, the reference region A similarity calculation unit that calculates the similarity of each position and size, a selection unit that selects a region having the highest similarity among the similarities calculated by the similarity calculation unit, and the image reading unit. Means for reading an image of only the selected area on the document may be provided.

Further, when there are a plurality of areas specified by the area specifying means, a first control means for notifying a warning and stopping reading of the image of the document, and when a plurality of areas specified by the area specifying means are provided, A second control means for selecting a reading target area from the respective areas and causing the image reading means to read an image of only the selected area on the original; and an image reading target area on the original. When there are a plurality of areas specified by the area specifying means, the position and size similarity with the reference area are calculated for each area, and each of the calculated areas is determined. Third control means for selecting an area having the highest similarity among the similarities and causing the image reading means to read an image of only the selected area on the document. , Means may be provided to selectively enable one of said first control means to said third control means.

In addition, when the region specifying unit cannot specify a region whose thickness is larger than the average value of the thickness of the document on the entire surface of the document, a warning is notified and the image of the document is displayed. A means for stopping reading may be provided.
Further, when the region specifying unit cannot specify a region where the thickness is larger than the average value of the thickness of the document on the entire surface of the document, a warning is notified and the image reading unit Means for reading an image of the entire surface of the original may be provided.
In addition, when the region specifying unit cannot specify a region whose thickness is larger than the average value of the thickness of the document on the entire surface of the document, a warning is notified and the image reading unit It is preferable to provide means for reading an image of only a preset area on the original.
Further, when the area specifying unit cannot specify an area whose thickness is larger than the average value of the thickness of the original on the entire surface of the original, a warning is notified and There may be provided designation means for designating an area to be read from among the above, and means for causing the image reading means to read an image of only the designated area on the document.

In addition, when the region specifying unit cannot specify a region whose thickness is larger than the average value of the thickness of the document on the entire surface of the document, a warning is notified and the image of the document is displayed. The first addition means for stopping reading and the area specifying means can specify the case where the area where the thickness is larger than the average value of the thickness of the original cannot be specified on the entire surface of the original. If there is not, a warning is given, and a second adding means for reading the entire image of the original by the image reading means , and a value obtained by averaging the thickness of the original on the entire surface of the original by the area specifying means. If the cases are when the thickness is large storage was identified could not be identified could not be identified, and issues a warning for the document on the said image reading means A third adding means to read the image of only the order set area, if the area thickness than the value obtained by averaging the thickness of the document is large on the whole surface of the document can not be identified by the area specifying means certain If it cannot be specified, a warning is notified, the area to be read is designated from the entire surface of the original, and an image of only the designated area on the original is read by the image reading means. It is preferable to provide means for selecting and validating any one of the fourth adding means for reading and the first to fourth adding means.
Further, switching means for switching between valid and invalid of the reading control means may be provided.

The image reading apparatus according to the present invention reduces the amount of image information necessary for character recognition by eliminating the need for a fixed format when capturing character information written in an area thicker than the periphery on the medium. The processing time for character recognition can be shortened.

1 is a block diagram illustrating a functional configuration of an image reading apparatus according to an embodiment of the present invention. 1 is a diagram showing an outline of a hardware configuration of an image reading apparatus which is an embodiment of the present invention. It is a flowchart figure which shows the original reading process in the image reading apparatus of this Example. FIG. 6 is an explanatory diagram for explaining reading of an image on the entire surface of a document. FIG. 10 is an explanatory diagram for explaining processing for specifying a region having a thickness different from the thickness of the document on the entire surface of the document.

It is a figure which shows the example of a main screen for setting thickness area | region reading mode. It is a figure which shows the example of designation | designated screen of a default area | region. It is a figure which shows the example of a setting screen at the time of area | region specification failure. It is a figure which shows the example of a setting screen at the time of multiple area | region specification. It is a figure which shows the example of a user selection screen.

Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.
〔Example〕
An image reading apparatus according to an embodiment of the present invention is an image forming apparatus including a facsimile machine, a copying machine, and a multifunction machine having a communication function and a copying function.
FIG. 1 is a block diagram showing a functional configuration of an image reading apparatus according to an embodiment of the present invention, and a part of the configuration is shown including the configuration shown in FIG.
FIG. 2 is a diagram showing an outline of the hardware configuration of the image reading apparatus according to the embodiment of the present invention.

As shown in FIG. 2, the hardware configuration of the image reading apparatus of this embodiment is an auto document having a document table 20, roller pairs 21 and 22, a document retainer 23 with a white sheet, a discharge tray 24, and a document thickness detection sensor 25. It has a feeder (ADF) 2, a contact glass 30, a light source (lamp) 31, reflectors (reflecting mirrors) 32 and 33, and a scanner 3 having an image sensor 34 including a CCD.
This image reading apparatus is a sheet-through document feeder (“sheet-through”) that reads an image of the original P while moving the original P while the light source 31 and the reflectors 32 and 33 are stopped under the control of the CPU described later. By a method (abbreviated as “DF”), an image of a specific area or the entire surface of the document P having a thickness different from the thickness of the document P is read on the entire surface of the document P serving as a medium, and the image data is captured.

First, the original P set on the original table 20 is conveyed by the roller pair 21 in the direction indicated by the arrow a in the figure, and once it is conveyed to the original reading position R of the original holder 23 with the white sheet, it is temporarily stopped.
During the conveyance, based on the thickness of the document P detected by the document thickness detection sensor 25, the width in the main scanning direction and the length in the sub-scanning direction of the document P are different from the thickness of the document P on the entire surface of the document P. Specify the thickness area.
Since a known technique may be used for the thickness detection process by the document thickness detection sensor 25, a detailed description thereof will be omitted.
Further, before starting the reading of the image of the original P, the light from the light source 31 is irradiated through the contact glass 30 to read the image of the white sheet (white reference plate) of the white sheet-attached original holder 23, and the image is based on the read result. Correct shading when reading. Since this shading correction is a known technique, a detailed description thereof will be omitted.

After the specification of the area and the shading correction, the document P is transported from the document reading position R, the light L is emitted from the light source 31 to the reading surface of the document P, and the reflected light L ′ is reflected from the reflecting plate 32. The image sensor 34 guides the image to the image sensor 34 through the image sensor 34. The image sensor 34 reads an image of only the specified area on the document P or an image of the entire surface of the document P based on an instruction from the CPU. take in. Then, a character recognition process is performed on the captured image data to acquire character information as a recognition result.
Further, the original P from which the image has been read is conveyed to the arrow b in the figure by the roller pair 22 and discharged to the discharge tray 24.

Next, the functional configuration of the image reading apparatus of this embodiment will be described.
As shown in FIG. 1, the image reading apparatus of this embodiment includes a CPU 1, an ADF 2, a scanner 3, an image processing unit (image processing unit, abbreviated as “IPU” in the figure) 4, an image data storage unit 5, A character recognition processing unit 6, an operation display unit 7, and a document thickness detection sensor 25 are provided.
The scanner 3 includes the units shown in FIG. 2 and functions as an image reading unit that reads an image of the document P.
Further, the ADF 2 includes the same components as shown in FIG. 2 and functions as a document conveying means for conveying the document P to the document reading position R of the scanner 3.
Further, the document thickness detection sensor 25 functions as a document thickness detection unit that detects the thickness of the document P before the document P conveyed by the ADF 2 reaches the document reading position R.

The image processing unit 4 is controlled by the CPU 1 to perform a shading correction process on the white sheet image data read by the scanner 3 and a series of known image processes (gamma correction and filter processes) on the image data read from the document P by the scanner 3. And the like are sent to the image data storage unit 5.
The image data storage unit 5 is a storage device (memory) that stores and stores image data that has been subjected to predetermined image processing by the image processing unit 4.

The character recognition processing unit 6 performs character recognition processing on the image data read from the document P stored in the image data storage unit 5 under the control of the CPU 1 to obtain character information (character data).
The operation display unit 7 includes an input device that receives input of various types of operation information from the user to the image reading device, and a display device that displays various work screens and messages for the user. The operation display unit 7 functions as a reference area designating unit for designating a reference area for determining an image reading target area on the document P, and selects and inputs a mode when reading the document P, and reads an image. Selection input of a target area, setting input of parameters necessary for a series of image processing in the image processing unit 4, and display of various warning messages are performed.

  The CPU 1 is responsible for overall control of the image reading apparatus. Before reading the image of the document P by the scanner 3, the CPU 1 controls the document P on the entire surface based on the thickness of the entire surface of the document P detected by the document thickness detection sensor 25. Area specifying means for specifying an area having a thickness different from the thickness of the image, a specific area reading means for reading an image of only the specified area on the document P by the scanner 3, and an area specified by the area specifying means. When there are a plurality of areas, a means for notifying a warning and stopping reading an image of the document P, and a selection section for selecting an area to be read from each area when there are a plurality of areas specified by the area specifying means. When there are a plurality of areas specified by the area specifying means, a similarity calculation unit that calculates the similarity between each area and the reference area. A selection unit that selects a region having the highest similarity among the similarities calculated by the similarity calculation unit, and a unit that causes the scanner 3 to read an image of only the selected region on the document P. Perform each function.

  Further, when there are a plurality of areas specified by the area specifying means, a first control means for notifying a warning and stopping reading an image of the document P, and when a plurality of areas specified by the area specifying means are provided, A second control means for selecting a region to be read from each of the regions and reading an image of only the selected region on the document P by the scanner 3 and a region to be read on the document P are determined. When there are a plurality of areas specified by the area specifying means, the similarity to the reference area is calculated for each area, and the most similar among the calculated similarities A third control unit that selects a region having a high similarity and causes the scanner 3 to read an image of only the selected region on the document P; and the first to third control units. Each function means to selectively enable one of the even play.

  Further, when the area specifying unit cannot specify an area having a thickness different from the thickness of the original P on the entire surface of the original P, a warning is issued and the reading of the image of the original P is stopped; When a region having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P by the means, a warning is notified and an image of the entire surface of the original P is read by the scanner 3 and the above-mentioned region specifying means Means for notifying a warning when an area having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P, and causing the scanner 3 to read an image of only a predetermined area on the original P; When the area specifying unit cannot specify an area having a thickness different from the thickness of the original P on the entire surface of the original P, a warning is notified and the reading target is detected from the entire upper surface of the original P. A specifying means for specifying a frequency, also serves the function of means to read the image of only the designated area on the document P by the scanner 3.

A first adding unit that issues a warning and stops reading an image of the document P when the region identification unit cannot identify a region having a thickness different from the thickness of the document P on the entire surface of the document P; A second adding means for notifying a warning and reading the image of the entire surface of the original P by the scanner 3 when the area specifying means cannot specify an area having a thickness different from the thickness of the original P on the entire surface of the original P; When the area specifying unit cannot specify an area having a thickness different from the thickness of the original P on the entire surface of the original P, a warning is notified and only the area preset on the original P by the scanner 3 is notified. When an area having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P by the third adding means for reading an image and the area specifying means, a warning is notified and Any one of a fourth adding means for causing the scanner 3 to designate a region to be read and causing the scanner 3 to read an image of only the designated region on the document P, and any one of the first to fourth adding means. It also functions as a means for selecting and enabling.
Further, it also functions as a switching means for switching between valid and invalid of the specific area reading means.

Next, document reading processing in the image reading apparatus of this embodiment will be described.
FIG. 3 is a flowchart showing document reading processing in the image reading apparatus of this embodiment.
In this process, based on the contents of the user setting by the operation display unit 7, the CPU 1 performs the process contents when there are a plurality of specific areas having a thickness different from the thickness of the document P on the entire surface of the document P, and the entire surface of the document P. The processing contents when the area having a thickness different from the thickness of the original P cannot be specified are different from each other.

The CPU 1 controls the operation display unit 7 to input “thickness region reading mode setting”, “setting at the time of region specification failure”, or “when multiple regions are specified” input from the operation display unit 7 in advance by the user before reading the document. Each content including “setting” is held in a memory (not shown). Based on the contents, the processing contents are changed at the time of image reading.
Further, the scanner 3 is controlled before reading the original P, and shading correction is performed by reading a white sheet.
Thereafter, when the ADF 2 and the scanner 3 are controlled and reading of the original is started, the scanner is set based on setting information such as a preset magnification and image quality in the reading setting process of step 1 (indicated by “S” in the figure). 3, various settings are made for various devices including 3, and in step 2, the document P is taken from the document table 20 and started to be conveyed. In step 3, it is determined whether or not the thickness area reading mode is set. Proceeding to step 12, a normal reading process is executed, and this process is terminated.

The normal reading process is a process in which when the leading end portion of the document P reaches the document reading position R, the image is read on the entire surface of the document P by the scanner 3 by continuing the conveyance as it is.
On the other hand, if it is determined in step 3 that the thickness area reading mode is set, the process proceeds to step 4 to execute document area specifying processing.
In this document area specifying process, the thickness of the entire surface of the document P is detected by the document thickness detection sensor 25 until the leading end of the document P reaches the document reading position R, and the CPU 1 detects the document based on the detection result. The width of P in the main scanning direction and the length in the sub-scanning direction are obtained, and based on these values and the thickness of the original P, the thickness of the original P is measured on the entire surface of the original P before reading the image of the original P. Identifies specific regions of different thicknesses. Then, when the leading edge of the document P reaches the document reading position R, the CPU 1 temporarily stops the conveyance of the document P.
When the CPU 1 completes the document area specifying process, the CPU 1 proceeds to step 5 to determine whether the number of specified areas is one.

If it is determined in step 5 that the number of specific areas is one, the ADF 2 and the scanner 3 are controlled, and the process proceeds to step 11 to execute an area reading process for reading an image of only the specified specific area on the document P. finish.
If it is determined in step 5 that the number of specific areas is not one, the process proceeds to step 6 to determine whether or not the number of specific areas is zero.
If it is determined in step 6 that the number of specific areas is 0, the process proceeds to step 7 to determine whether or not to read the entire image of the original P based on the above setting contents. The process is executed and this process is terminated.
If it is determined in step 7 that the image of the entire surface of the document P is not read, the process proceeds to step 8 to determine whether or not to stop reading the image of the document P based on the set contents. If it is determined not to stop reading the image, the process proceeds to step 9 to determine whether or not to read the default area based on the selection result by the user.

If it is determined in step 9 that the default area is not read, the operation display unit 7 is controlled, and the process proceeds to step 10 where the user designates the area to be read in the entire surface of the document P from the operation display unit 7, and to step 11. Then, the area reading process for reading only the image of the area to be read designated by the user is executed, and this process is terminated.
If it is determined in step 9 that the default area is to be read, the process proceeds to step 15 to select a default area for the document P, and the process proceeds to step 11 to read only the image of the selected default area to be read. To terminate this process.
On the other hand, if it is determined in step 6 that the number of specific areas is not 0 (plural), the process proceeds to step 13 to determine whether or not to stop reading the image of the document P based on the above setting contents.
If it is determined in step 13 that reading of the image of the document P is to be stopped, the process proceeds to step 14 where it is determined that the reading target region cannot be determined because there are a plurality of specific regions on the operation display unit 7 and reading of the document P is stopped. An error notification is displayed, the ADF 2 and the scanner 3 are controlled, reading of the image of the original P is stopped, and this process is terminated.

If it is determined in step 13 that reading of the image of the document P is not stopped, the process proceeds to step 16 to determine whether or not a similar region is selected based on the above setting contents.
If it is determined in step 16 that the similar area is selected, the process proceeds to step 17 to select a specific area having the highest similarity to the reference area from the plurality of specific areas, and then proceeds to step 11 to select the selected area on the document P. An area reading process for reading an image of only a specific area is executed, and this process ends.
On the other hand, if it is determined in step 16 that the similar area is not selected, the operation display unit 7 is controlled, the process proceeds to step 18, the area is selected from the operation display unit 7 by the user, and the process proceeds to step 11 where An area reading process for reading an image of only the area specified by the user is executed, and this process is terminated.
In this way, the CPU 1 performs an image reading process by performing a process of selecting and validating any one of a plurality of types of process contents based on preset setting contents.

Next, reading of an image on the entire surface of the document P will be described.
FIG. 4 is an explanatory diagram for explaining reading of an image on the entire surface of the document P.
The arrow direction in the figure is the conveyance direction of the document P.
When the document P is transported and the leading end reaches the document reading position R, the CPU 1 asserts (validates) a signal (hereinafter referred to as “L gate signal”) indicating a valid period of reading of the document P in the main scanning direction to the scanner 3. This signal is used as a trigger to start reading an image on the original P, and a signal indicating the effective period of reading in the sub-scanning direction (hereinafter referred to as “F gate signal”) is asserted (effective). When the document reading position R is passed, the F gate signal is negated (invalidated). The image sensor 34 reads an image while the L gate signal and the F gate signal are asserted.
Thus, the reading range on the original P can be freely controlled by controlling the F gate signal and the L gate signal.

Next, a process for specifying a region having a thickness different from the thickness of the original P on the entire surface of the original P will be described.
FIG. 5 is an explanatory diagram for explaining a process of specifying a region having a thickness different from the thickness of the document P on the entire surface of the document P.
The document thickness detection sensor 25 is a line sensor in which a large number of sensors are arranged in a line, and is arranged in parallel to the main scanning direction of the document P. Therefore, by transporting the document P, the document thickness detection sensor 25 senses the document P and sends the sensor information to the CPU 1.
The CPU 1 can acquire the thickness information of the entire surface of the document P two-dimensionally by sampling the sensor information from the document thickness detection sensor 25 in time series.
Based on the acquired two-dimensional thickness information of the original P, first, the width of the original P in the main scanning direction and the length in the sub-scanning direction are obtained.

Regarding the width in the main scanning direction and the length in the sub-scanning direction of the document P, the width in the main scanning direction is obtained from the length of each sensor that detects the thickness of the document P by the document thickness detection sensor 25. The length in the sub-scanning direction is obtained based on the section in which the thickness of the document P is detected by the document thickness detection sensor 25 and the transport time of the document P.
Further, an area 41 having a thickness different from that of the periphery is searched for on the entire surface of the document P. Since this search process may use a known technique, a detailed description of the search algorithm is omitted.
Thus, the area 41 is specified, and the coordinate values (X1, Y1) of the start point and the coordinate values (X2, Y2) of the end point with respect to the coordinate value of the reference point O of the document P in the area 41 are held.
Although the specific area is rectangular here, areas having other shapes can be recognized as the specific area.

Regarding the reading process of the image of only the area 41, the CPU 1 performs the image reading conveyance of the document P based on the coordinate values (X1, Y1) of the start point and the coordinate values (X2, Y2) of the end point of the area 41. The start of the L gate signal to the scanner 3 is delayed by X1, the assertion period is set to X2-X1, the F gate signal is delayed by Y1, and negated after being asserted by the period of Y2-Y1.
By controlling in this way, it is possible to read an image of only the specified area 41 from the original P.
For example, when a sheet (corresponding to the area 41) in which the address and address are written is attached to a postcard (corresponding to the original P), an image of only the portion of the sheet that is thicker than the postcard is read from the postcard The address and address can be obtained from the image by character recognition.

In this way, it is possible to detect areas having different document thicknesses (thicknesses) and read only the images in the areas.
For example, for envelopes and postcards with destination stickers (especially the format may not be specified), the thickness of the destination sticker is detected and only the information written on the destination sticker is read. When it is desired to acquire the image, only the image of the destination portion can be read without requiring a special operation such as an accurate area designation by the user.
Therefore, a standard format is not prepared, and an area to be read is determined before reading. Therefore, the amount of image data to be processed can be reduced, and the processing speed of image reading and character recognition can be increased.

Next, processing for selecting a specific area to be read based on the similarity to the default area when a plurality of specific areas are specified from the document P will be described.
The default area is a reference area for determining an image reading target area on the document P.
For the default area on the document P, the coordinate value (Xd1, Yd1) of the start point and the coordinate value (Xd2, Yd2) of the end point are set, and the coordinate value (Xt1, Yt1) of the start point and the end point In the case of coordinate values (Xt2, Yt2), a case will be described in which the proximity of the distance at the center position is used as the first index of similarity and the proximity of the area is used as the second index of similarity.
First, from the coordinate value (X1, Y1) of the start point of the default area and the coordinate value (X2, Y2) of the end point, the coordinate value of the center position of the default area is ((X1 + X2) / 2, (Y1 + Y2) / 2). It becomes.

Therefore, the square Dist1 of the distance between the center position of the default area and the center position of the specific area is obtained by processing based on the following equation (1).
[Equation 1]
Dist1 = ((Xt1 + Xt2) / 2− (Xd1 + Xd2) / 2) ^ 2 + ((Yt1 + Yt2) / 2− (Yd1 + Yd2) / 2) ^ 2
The smaller the Dist1 is, the higher the similarity between the specific area and the default area is.
Next, the area of the default region is obtained by processing based on the following equation 2.
[Equation 2]
(X2-X1) * (Y2-Y1)
Then, the area difference Dist2 between the area of the default area and the area of the specific area is obtained by the processing based on the following Equation 3.

[Equation 3]
Dist2 = | (Xt2-Xt1) * (Yt2-Yt1)-(Xd2-Xd1) * (Yd2-Yd1) |
The smaller the area difference Dist2, the higher the similarity between the specific area and the default area.
As described above, when a plurality of specific areas are found on the document P, the similarity to the default area is calculated for each specific area, and the specific area having the highest similarity is selected as a reading target.
In this embodiment, the proximity of the center position is used as the first index of similarity, and the closeness of the area is used as the second index of similarity. If they have the same degree of similarity, they are compared by area difference. If they are still the same, select the area that was earlier in the search order.

Next, each setting screen and selection screen in the operation display unit 7 will be described.
FIG. 6 is a diagram showing an example of a main screen for setting the thickness area reading mode.
The thickness area reading mode is a setting in which an area having a thickness different from the thickness of the original P is specified on the entire surface based on the thickness of the entire surface of the original P, and an image of only the specific area is read.
In the setting screen of the thickness area reading mode indicated by an arrow 50 in the figure, this setting screen enables the thickness area reading mode when the “Yes” button 51 is pressed, and the thickness area reading mode is set when the “No” button 52 is pressed. Can be disabled and put into normal reading mode.
Further, when the “setting” button 54 is pressed in the default area designation field indicated by an arrow 53 in the figure, the screen shifts to a default area designation screen.
Furthermore, when the “setting” button 56 is pressed in the area specification failure setting field indicated by an arrow 55 in the drawing, the screen shifts to the area specification failure setting screen.
Furthermore, when the “setting” button 58 is pressed in the multi-region specifying time setting field indicated by an arrow 57 in the drawing, the multi-region specifying time setting screen is displayed.
The contents specified on this screen are referred to during the image reading process.

FIG. 7 is a diagram illustrating an example of a default area designation screen.
This default area is used as a reference area for determining an image reading target area on the original P. Further, when a specific area cannot be specified from the original P, it can be used as a reading target area.
In this designation screen, when the coordinate position 60 of the start point and the coordinate position 61 of the end point of the default area in the rectangle 59 indicating the area of the document P are designated, the coordinates of the start point are displayed in the start coordinate field of the arrow 62 in the figure. For example, the value is displayed as (X1, Y1) = (20, 20), and the coordinate value of the end point is, for example, (X2, Y2) = (80, 80) in the end coordinate field indicated by arrow 63 in the figure. The desired default area can be designated on the original P.
It is also possible to directly input and set coordinate values in the respective fields indicated by arrows 62 and 63 in the figure. In this case, the input start point and end point and the specific area indicated by these points are displayed on the rectangle 59. Can also be displayed.
The contents specified on this screen are referred to during the image reading process.

FIG. 8 is a diagram illustrating an example of a setting screen when region identification fails.
This area specification failure setting screen is a screen for setting processing contents when an area having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P, and is one of 64 to 67 in the figure. You can select by pressing one button.
When the reading stop button 64 is pressed, image reading can be stopped when an area having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P.
Further, when the full-page reading button 65 is pressed, an image on the entire surface of the original P can be read when an area having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P.
Further, when the user selection button 66 is pressed, if the area having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P, the user can designate the reading target area.
In addition, when the default area selection button 67 is pressed, a default area can be automatically selected as a reading target area when an area having a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P. .
The contents specified on this screen are referred to during the image reading process.

FIG. 9 is a diagram showing a setting screen example when a plurality of areas are specified.
This setting screen is a screen for setting processing contents when a plurality of areas having a thickness different from the thickness of the original P can be specified on the entire surface of the original P, and one of the buttons 68 to 70 in FIG. Can be selected.
When the reading stop button 68 is pressed, image reading can be stopped when a plurality of areas having a thickness different from the thickness of the original P can be specified on the entire surface of the original P.
In addition, when the user selection button 69 is pressed, when a plurality of areas having a thickness different from the thickness of the original P can be specified on the entire surface of the original P, a screen for selecting a reading target area by the user can be displayed.
The content specified on this selection screen is referred to during the image reading process.
Further, when the similar area selection button 70 is pressed, when a plurality of areas having a thickness different from the thickness of the original P can be specified on the entire surface of the original P, the specific area having the highest similarity with the default area is automatically selected. In addition, it is possible to read an image of only the specific area.

FIG. 10 is a diagram illustrating an example of a user selection screen.
This user selection screen is a setting screen for specifying a plurality of areas on the entire surface of the original P, and when a plurality of areas having a thickness different from the thickness of the original P can be specified. This screen is displayed when the selection is set.
In this user selection screen, the entire area 71 of the document P is displayed on the screen, and a plurality of area rectangles 72 to 74 specified from the document P are displayed in the entire area 71.
When the user selects and designates a desired rectangle, for example, the rectangle 72 as the specific area to be read, the number “1” given to the rectangle 72 as the read area is displayed in the column of arrow 75 in the figure. .
Therefore, an image of only a specific area corresponding to the rectangle 72 selected by the user from the document P is read.

In addition, the number “1” directly assigned to the rectangle 72 can be selected in the field indicated by the arrow 75 in the drawing. In that case, the rectangle 72 may be highlighted (flashing or changing the display color).
If an area with a thickness different from the thickness of the original P cannot be specified on the entire surface of the original P, a screen similar to the default area designation screen shown in FIG. 7 is displayed, and the default area is set as the reading target area. It is good to make it specify.
The contents designated on each screen are referred to during the image reading process.

The image reading apparatus according to this embodiment can detect areas having different thicknesses in a document and read only partial information of the areas having different thicknesses.
Further, since the thickness region is specified before the document reaches the reading position, only the necessary image portion can be read when the image is actually read.
Therefore, the amount of image data to be accumulated is small, and processing such as position specification is not performed after once reading, so that the processing time for image reading and character recognition can be shortened.
Further, when it is not necessary to cut out the image of the thickness region (when it is desired to read the entire image), the information desired by the user can be obtained by invalidating the mode.
Furthermore, image reading can be temporarily stopped when a plurality of thickness regions exist in the document (for example, stamps are affixed) or when an erroneous detection of the thickness region occurs. After the stop, the user can confirm and read again.
In addition, after the stop, the user can confirm the image reading area, and can obtain information desired by the user more accurately.

Furthermore, when there are a plurality of thickness regions in the document, the image is read by selecting the region to be read without bothering the user, so that information can be obtained from a desired location on the document preset by the user. Can do.
In addition, when there is no thickness region or when an erroneous detection of the thickness region occurs, reading can be stopped once, and after the stop, reading can be performed again after confirmation by the user.
Further, all information can be stored just in case, for example, when there is no thickness region or when an erroneous detection of the thickness region occurs.
Also, only information close to the user's desire can be stored just in case the thickness area does not exist or the thickness area is erroneously detected.
Furthermore, information desired by the user can be obtained more accurately even when there is no thickness region or when a false detection of the thickness region occurs.
Furthermore, since the processing contents according to the user's preference can be executed from among a plurality of types of processing contents that can be executed at the time of document reading, the operability for the user can be improved.

  The image reading apparatus according to the present invention can be applied to all image reading apparatuses having an image reading function including an image scanner, a digital copying machine, a facsimile machine, a printer, a multifunction peripheral, and a network file server.

1: CPU 2: ADF 3: Scanner 4: IPU 5: Image Data Storage Unit 6: Character Recognition Processing Unit 7: Operation Display Unit 20: Document Table 21, 22: Roller Pair 23: Document Press with White Sheet 24: Ejection Tray 25: Document thickness detection sensor 30: Contact glass 31: Light source 32, 33: Reflector 34: Image sensor

JP 2003-203202 A JP-A-2005-007355

Claims (11)

Image reading means for reading an image of a document;
Document conveying means for conveying the document to a reading position of the image reading means;
Document thickness detection means for detecting the thickness of the document before the document transported by the document transport means reaches the reading position;
Based on a value obtained by averaging the thickness of the original on the entire surface based on a value obtained by averaging the thickness of the entire surface of the original detected by the document thickness detecting means before reading the image of the original by the image reading means. An area specifying means for specifying an area having a large thickness ;
An image reading apparatus comprising: a reading control unit that causes the image reading unit to read an image of only the specified area on the document.   2. The image reading apparatus according to claim 1, further comprising means for notifying a warning when there are a plurality of areas specified by the area specifying means and stopping reading the image of the document.   When there are a plurality of areas specified by the area specifying means, a selection means for selecting an area to be read from each area, and an image of only the selected area on the original is read by the image reading means. The image reading apparatus according to claim 1, further comprising: A reference area designating unit for designating a reference area for determining an image reading target area on the original;
When there are a plurality of areas specified by the area specifying means, similarity calculation means for calculating the position and size similarity with the reference area for each area;
A selecting means for selecting a region having the highest similarity among the similarities calculated by the similarity calculating means;
2. The image reading apparatus according to claim 1, further comprising means for causing the image reading means to read an image of only the selected area on the document. A first control means for notifying a warning when there are a plurality of areas specified by the area specifying means and stopping reading an image of the document;
When there are a plurality of areas specified by the area specifying means, a reading target area is selected from the areas, and the image reading means reads the image of only the selected area on the document. Control means;
When a reference area for determining an area to be read of an image is specified on the document, and there are a plurality of areas specified by the area specifying unit, the similarity of the position and the size of each area with the reference area And a third control means for causing the image reading means to read an image of only the selected area on the document by selecting the area having the highest similarity among the calculated similarities. ,
2. The image reading apparatus according to claim 1, further comprising means for selecting and enabling one of the first control means to the third control means. Provided with means for notifying a warning and stopping reading the image of the original when the area specifying means cannot specify an area whose thickness is larger than the average value of the thickness of the original on the entire surface of the original. The image reading apparatus according to claim 1, wherein the image reading apparatus is an image reading apparatus. When the area specifying unit cannot specify an area having a thickness larger than the average value of the thickness of the original on the entire surface of the original, a warning is notified, and the image on the entire surface of the original is read by the image reading unit. The image reading apparatus according to claim 1, further comprising: an image reading unit. If the area specifying unit cannot identify an area whose thickness is larger than the average value of the thickness of the original on the entire surface of the original, a warning is notified, and the image reading unit presets the area on the original. 6. The image reading apparatus according to claim 1, further comprising means for reading an image of only the region that has been set. When the area specifying unit cannot identify an area having a thickness larger than the average value of the thickness of the original on the entire surface of the original, a warning is notified and the area to be read is selected from the entire area on the original. The image reading apparatus according to any one of claims 1 to 5, further comprising: designation means for designating; and means for causing the image reading means to read an image of only the designated area on the document. apparatus. First adding means for notifying a warning and stopping reading of the image of the original when the area specifying means cannot specify an area having a thickness larger than the average value of the thickness of the original on the entire surface of the original. When,
When the area specifying unit cannot specify an area having a thickness larger than the average value of the thickness of the original on the entire surface of the original, a warning is notified, and the image on the entire surface of the original is read by the image reading unit. Second adding means
If the area specifying unit cannot identify an area whose thickness is larger than the average value of the thickness of the original on the entire surface of the original, a warning is notified, and the image reading unit presets the area on the original. Third adding means for reading an image of only the region that has been set,
When the area specifying unit cannot identify an area having a thickness larger than the average value of the thickness of the original on the entire surface of the original, a warning is notified and the area to be read is selected from the entire area on the original. Fourth adding means for causing the image reading means to read an image of only the designated area on the document;
6. The image reading apparatus according to claim 1, further comprising: a unit that selects and validates any one of the first addition unit to the fourth addition unit. The image reading apparatus according to claim 1, further comprising a switching unit that switches between valid and invalid of the reading control unit .

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