JP2008301115A - Image processing apparatus, identifying method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for correctly and efficiently identifying a plurality of media which are disposed side by side when media and documents are identified by reading pattern images embedded in the media. <P>SOLUTION: An image processing apparatus includes an area setting unit 121 which sets an analytic area to be analyzed in an image read out of a recording medium, a partial image area selection unit 122 which sets a plurality of reference decoding positions within the analytic area at intervals larger than specified and selects partial images at the reference decoding positions, a decoding unit 123 which decodes identification information of the recording medium from the partial images, and an identification unit 124 which identifies the recording medium based upon the decoded identification information, wherein the area setting unit 121 sets a plurality of new analytic areas by dividing the current analytic area when a plurality of recording media are identified for the one analytic area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, an identification method, and a program.

  Embed a pattern image representing information coded on a medium such as printing paper or a pattern image with a specific meaning, read it with a reading device, decode the code information, and control the device according to the given meaning It has been performed conventionally (see, for example, Patent Documents 1 to 3). Information represented by the pattern image includes identification information of the medium itself in which the pattern image is embedded, identification information of a document recorded on the medium, position information indicating a position on the medium, and the like.

  Patent Document 1 discloses the following technique. When performing a copying process using the image reading means and the image output means of the image reading means, the decoding means for decoding the document ID mark obtained from the image reading means, and the document ID code obtained from the decoding means The document management means for specifying the corresponding document based on the output and outputting the position data of the document ID mark attached to the document, and the document ID mark position of the image data input from the image reading means Pattern synthesizing means for synthesizing the images and passing them to the output means.

  Patent Document 2 discloses the following technique. The document security management system includes an image forming apparatus and a security server connected to the image forming apparatus via a network. The security server generates a first profile management table (15) for generating and recording a profile of an electronic document when an electronic document is generated by the image forming apparatus, and a print document is generated by the image forming apparatus. And a second profile management table (16) for generating and recording the profile of the print document in association with the ID of the document from which the print document is derived. When outputting the print document, the image forming apparatus embeds a new print ID in the print document and prints it.

  Patent Document 3 discloses the following technique. The information processing system includes a device that allows a position-coded base to be printed on demand. In this device, the current graphic object is selected from a set of graphic objects pre-stored in the system, each of these pre-stored graphic objects defining graphic information, and It corresponds to a rule object that relates at least one processing standard to graphic information.

JP 2000-13484 A Japanese Patent Laying-Open No. 2005-259108 JP-T-2006-504181

  Consider a case in which a plurality of media embedded with pattern images as described above are arranged and the pattern image is read by a scanner to identify the media itself or a document recorded on the media. In this case, if the processing ends when the identification can be performed based on the pattern image read in a limited range such as immediately after the start of scanning, only the medium at the scanning start position is identified, It is conceivable that the medium is not identified. On the other hand, if an attempt is made to scan and identify the entire medium in order to prevent such omission of identification, the processing takes a lot of time, and the operation efficiency of the apparatus is lowered.

  The present invention has been made in view of the above problems, and when a pattern image embedded in a medium is read to identify a medium or a document, a plurality of media arranged side by side are correctly and efficiently used. The purpose is to provide a technology for identification.

The invention according to claim 1, which achieves the above object,
An area setting unit that sets an analysis area to be analyzed for an image read from a recording medium;
A partial image selection unit that sets a plurality of decoding reference positions with a predetermined interval or more in the analysis region, and selects a partial image at the decoding reference position;
A decoding unit for decoding the identification information of the recording medium from the partial image;
An image processing apparatus comprising: an identification unit that identifies the recording medium based on the decoded identification information.
The invention according to claim 2
The region setting unit divides the analysis region and sets a plurality of new analysis regions when a plurality of recording media are identified by the identification unit for one analysis region. An image processing apparatus according to claim 1.
The invention according to claim 3
The image processing apparatus according to claim 2, wherein the region setting unit divides the analysis region so that a long side of the rectangular analysis region is divided into two equal parts.
The invention according to claim 4
When the identification information of the same recording medium is decoded from the partial images at the decoding reference position set in the plurality of analysis areas, the area setting unit changes the boundaries of the plurality of analysis areas again. The image processing apparatus according to claim 2, wherein the image processing apparatus is divided.
The invention according to claim 5
The image processing apparatus according to claim 1, wherein the partial image selection unit uses, as the decoding reference position, two corners positioned on a predetermined diagonal in the rectangular analysis region.
The invention according to claim 6
The image processing apparatus according to claim 1, wherein the partial image selection unit sets four corners in the rectangular analysis region as the decoding reference position.
The invention according to claim 7 provides:
The partial image selection unit sets a position of a reference point included in the analysis area as a reference decoding position among reference points set for a reading area that can be read by a reading device of the recording medium. The image processing apparatus according to claim 1, wherein the image processing apparatus is an image processing apparatus.
The invention according to claim 8 provides:
Read the image formed on the recording medium,
For the scanned image, set the analysis area to be analyzed,
In the analysis area, set a plurality of decoding reference positions with a certain interval or more, select a partial image of the decoding reference position,
Decoding the recording medium identification information from the partial image;
Identifying the recording medium based on the decrypted identification information;
In the identification method, when a plurality of recording media are identified for one analysis area, the analysis area is divided and a plurality of new analysis areas are set.
The invention according to claim 9 is:
When identification information of the same recording medium is decoded from the partial image at the decoding reference position set in a plurality of analysis areas, the boundary of the plurality of analysis areas is changed and divided again. The identification method according to claim 8.
The invention according to claim 10 is:
On the computer,
A function for setting an analysis area to be analyzed for an image read from a recording medium;
In the analysis region, a function of setting a plurality of decoding reference positions with a certain interval or more, and selecting a partial image at the decoding reference position;
A function of decoding identification information of the recording medium from the partial image;
A program for realizing a function of identifying the recording medium based on the decoded identification information.
The invention according to claim 11 is:
As a function of setting the analysis area, when a plurality of recording media are identified for one analysis area, the computer executes processing for dividing the analysis area and setting a plurality of new analysis areas The program according to claim 10, wherein the program is executed.
The invention according to claim 12
As a function of setting the analysis area, when the identification information of the same recording medium is decoded from the partial image at the decoding reference position set in the plurality of analysis areas, the boundary of the plurality of analysis areas is changed. The program according to claim 10, further causing the computer to execute a process of dividing again.

According to the first aspect of the present invention, when a pattern image embedded in a medium is read to identify a medium or a document, a plurality of media arranged side by side can be correctly and efficiently identified.
According to the second aspect of the invention, a plurality of media can be identified in more detail by dividing the analysis region.
According to the invention of claim 3, when a plurality of media of standard size are arranged, it can be identified particularly efficiently.
According to the invention which concerns on Claim 4, a medium can be identified efficiently corresponding to the medium of various sizes and shapes flexibly.
According to the fifth aspect of the present invention, the medium can be identified with the minimum apparatus load.
According to the sixth aspect of the invention, a medium can be identified particularly efficiently in a rectangular medium.
According to the invention which concerns on Claim 7, a medium can be identified efficiently corresponding to the medium of a complicated shape.
According to the eighth aspect of the present invention, when a pattern image embedded in a medium is read to identify a medium or a document, a plurality of media arranged side by side are correctly and efficiently divided by dividing the analysis area. Can be identified.
According to the ninth aspect of the present invention, it is possible to efficiently identify a medium flexibly corresponding to media of various sizes and shapes.
According to the tenth aspect of the present invention, when a pattern image embedded in a medium is read by a computer to identify a medium or a document, a plurality of media arranged side by side can be identified correctly and efficiently.
According to the invention which concerns on Claim 11, a some medium can be identified in detail by dividing | segmenting an analysis area | region.
According to the twelfth aspect of the present invention, it is possible to efficiently identify a medium flexibly corresponding to media of various sizes and shapes.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described below in detail with reference to the accompanying drawings.
<Reader>
FIG. 1 is a diagram illustrating a functional configuration example of a reading device.
As illustrated in FIG. 1, the image processing apparatus 100 includes a reading unit 110 for reading an image, an analysis unit 120 that analyzes a pattern image obtained from the read image, and a holding unit 130 that holds the read image. With.

  The reading unit 110 reads an image from a medium on which an image (including a pattern image and a document image described later) is formed. As the reading unit 110, a scanner that applies light to a medium to be read, reads reflected light, and converts the light into digital data can be used. In that case, for example, light is emitted from the LED (Light Emitting Diode) light source to the medium surface, the reflected light is optically reduced by the imaging lens, and the formed optical image is photoelectrically converted by the image sensor. It is possible to adopt a configuration of performing.

  In the present embodiment, a document image obtained by imaging an electronic document and a pattern image (hereinafter referred to as a code image) representing coded information are formed on a medium. In this case, the document image is formed with visible toner, while the code image is formed with invisible toner having an absorption wavelength in the infrared region, for example. Therefore, as an LED light source, in addition to, for example, a white LED that emits visible light, an infrared LED that emits infrared light is provided. As the image sensor, not only a sensor for red light, a sensor for green light, and a sensor for blue light, but also a sensor for infrared light is provided. Alternatively, a method of irradiating both visible light and infrared light, filtering the reflected light, and extracting a document image and a code image may be used.

The analysis unit 120 receives the code image read by the reading unit 110, analyzes the code image, and analyzes the identification information (hereinafter referred to as “original document”) recorded on the recording medium to be read. "Original document ID"). The function of the analysis unit 120 is realized when a CPU provided as control means in the image processing apparatus 100 executes a program read into the main memory. Here, the original document ID includes information about the device that output the original document and the time.
In addition, the analysis unit 120 of the present embodiment analyzes the code image read from a plurality of specific positions in order to recognize the arrangement state of the medium when read by the reading unit 110. Details of processing by the analysis unit 120 will be described later.

  The holding unit 130 is realized by a memory such as a RAM, a magnetic disk device, or other storage unit, and holds an image (including a pattern image and a document image) read by the reading unit 110. The image held in the holding unit 130 is used in various ways depending on the function of the image processing apparatus 100. For example, if the image processing apparatus 100 is a scanner device connected to a host computer, the image held in the holding unit 130 is transmitted to the host computer via a LAN (Local Area Network) or the like. If the image processing apparatus 100 is a copying machine, the image held in the holding unit 130 is printed out on the medium by an image forming mechanism that forms an image on the medium using an image forming material such as toner. The If the image processing apparatus 100 is a facsimile, the image held in the holding unit 130 is transmitted to the destination device via the telephone line.

<Function of analysis unit>
Next, the function of the analysis unit 120 will be described in more detail.
As shown in FIG. 1, the analysis unit 120 includes an area setting unit 121 that sets an area to be processed, and a partial image selection unit 122 that selects a plurality of partial images from the read images of the set area. The analysis unit 120 also includes a decoding unit 123 that decodes the original document ID from the code image included in the selected partial image, and an identification unit 124 that identifies the original document based on the decoded original document ID.

  The area setting unit 121 sets an analysis target area (hereinafter, an analysis area) for the image read by the reading unit 110. Initially, this analysis area coincides with the entire medium to be read. In the reading unit 110, when a plurality of media are arranged as reading targets, the whole of the plurality of media is an analysis region. As a specific example, when two A4 size media are arranged with their long sides aligned, the analysis area has a standard size of A3 size. Such initial information of the analysis region is obtained from the reading unit 110, for example. When the reading unit 110 is a flat head type scanner, the size of a medium on which an original document to be read placed on a platen glass serving as an original table is recorded is generally recognized prior to reading an image. An analysis area may be set based on the recognition result.

  In addition, when a plurality of original document IDs are obtained from one analysis region as a result of the processing by the decryption unit 123 and the identification unit 124, the region setting unit 121 divides the current analysis region and sets a new analysis region. Set. Specifically, for example, two analysis areas are set by dividing the current analysis area into two equal parts. Since the medium to be read is usually a standard size such as A size or B size, the possibility of obtaining an appropriate analysis region is increased by dividing the long side into two equal parts. In addition, although some division methods are conceivable, details of the setting area dividing method by the area setting unit 121 will be described later.

  The partial image selection unit 122 specifies a plurality of positions (hereinafter referred to as decoding reference positions) used for decoding the original document ID from the analysis region set by the region setting unit 121, and decodes the partial image at the specified decoding reference position. Select as target. The partial image to be decoded needs to have an area including at least one code image in which the original document ID is recorded in order to decode the original document ID from the partial image. In order to suppress an increase in the load on the image processing apparatus 100 due to image processing for decoding the original document ID, it is preferable that the image is a small image. Accordingly, the partial image is set to a size that includes, for example, one entire code image.

  There are several possible methods for setting the decoding reference position. First, there is a method of setting based on the shape of the analysis region. Specifically, for example, two corners located on the diagonal line of the analysis region are set as the decoding reference position. When multiple media are included in the analysis area, it is considered that each of the decoding reference positions is distributed over the plurality of media by separating the intervals of the plurality of decoding reference positions as much as possible, so that it is possible to reliably detect the plurality of media. It is done. Therefore, by selecting two corners on the diagonal line, the two most distant locations in the analysis region can be obtained.

FIG. 2 is a diagram illustrating an example in which two corners located on the diagonal line of the analysis region are set as decoding reference positions.
In the example shown in the figure, two A5 size media are arranged as reading objects, and an analysis area corresponding to the standard size of A4 size including the medium is set. The analysis area is indicated by a thick broken line. The decoding reference positions are set at two locations, the upper left corner and the lower right corner of the analysis area (indicated by gray square marks in the figure, and so on). If a partial image is selected from these decoding reference positions and the original document ID is decoded, the original document IDs (ID1 and ID2) recorded in each medium are obtained, and a plurality of media are included in the analysis area. Is detected.

  Further, all four corners of the analysis area may be set as the decoding reference position. For example, consider a case where two long media having the same length as the long side of the A4 size and half the width of the short side are arranged to set an analysis area of the A4 size. In this case, if only two locations on the diagonal line are set as the decoding reference positions, it can be detected that a plurality of media are included in the analysis region. It cannot be judged whether the media are lined up. If the four corners of the analysis area are set as decoding reference positions, it is possible to deal with a medium that is not a standard size such as A size or B size. Such information is considered in the division of the analysis area by the area setting unit 121.

FIG. 3 is a diagram illustrating an example in which four corners of the analysis region are set as decoding reference positions.
In the illustrated example, two A5 size media are arranged in the same manner as in FIG. 2, and an analysis region corresponding to the A4 size is set (thick broken line). The decoding reference positions are set at four locations at each corner of the analysis area. If a partial image is selected from these decoding reference positions and the original document ID is decoded, ID1 is obtained from the two decoding reference positions on the left side in the analysis area in the figure, and ID2 is obtained from the two decoding reference positions on the right side. Therefore, the position and shape of each medium are roughly recognized.

  Next, as another method for selecting the decoding reference position, there is a method in which an area that can be read by the reading unit 110 (reading area) is fixedly set in advance. In this case, a plurality of reference points are set at specific intervals in the reading area of the reading unit 110. After the analysis region is set, the partial image selection unit 122 sets the position of the reference point included in the analysis region as the decoding reference position regardless of the shape of the set analysis region.

FIG. 4 is a diagram illustrating an example in which the decoding reference position is set based on a reference point fixedly set for the reading area.
In the illustrated example, a plurality of reference points (indicated by white square marks in the figure) are arranged in the reading area of the reading unit 110 at regular intervals in the vertical and horizontal directions. An analysis area (thick broken line) formed by two A5 size media is included in the reading area. Then, among the reference points arranged in the reading area, those included in the analysis area are set as decoding reference positions on the analysis area.

The decoding unit 123 performs image processing on the partial image selected by the partial image selection unit 122 to extract a code image, and decodes the original document ID that has been encoded and recorded.
The identifying unit 124 identifies the original document based on the original document ID decrypted by the decrypting unit 123. The identification of the original document may be performed, for example, by storing a table in which the original document ID and the original document are associated with each other in a storage device inside the image processing apparatus 100, or by referring to the electronic document. This may be done by sending an inquiry to the document management server that manages the document by sending the decrypted original document ID.

<Reading method>
Next, an image reading method by the image processing apparatus 100 will be described.
First, the analysis region setting method (division method) by the region setting unit 121 will be described in detail.

FIG. 5 is a flowchart for explaining the operation of the area setting unit 121.
As shown in FIG. 5, the area setting unit 121 first sets an analysis area including the entire recording medium (including a plurality of cases) read by the reading unit 110 as an initial setting (step 501). After the partial image is selected by the partial image selection unit 122 for the set analysis region, the original document ID is decoded by the decoding unit 123, and the original document is identified by the identification unit 124, the region setting unit 121 It is determined whether or not a plurality of original document IDs are included in one analysis area (step 502). When a plurality of original document IDs are not included in one analysis area, the analysis area is appropriately set, and the process is terminated.

  On the other hand, when a plurality of original document IDs are included in one analysis area, the area setting unit 121 divides the current analysis area and sets a new analysis area (step 503). After the partial image is selected, the original document ID is decoded, and the original document is identified for the newly set analysis area, the area setting unit 121 sets the same original document ID in the plurality of analysis areas. Is included (step 504). When the same original document ID is included in a plurality of analysis areas, it means that a single original document is divided by the boundaries of the analysis areas. Therefore, the region setting unit 121 changes the boundary of the analysis region and divides the analysis region again (step 505). As a method for changing the boundary of the analysis region, for example, a method of setting it between the current boundary and another boundary can be considered. Details of this changing method will be described later.

If one original document ID is not included in a plurality of analysis areas, the area setting unit 121 returns to step 502 and determines whether or not a plurality of original document IDs are included for each analysis area. Thereafter, the operations in and after step 502 are repeated for each analysis area, and when one analysis area includes one original document ID for all analysis areas, the process ends.
In the above operation, the determination of step 502 and step 504 is performed by the region setting unit 121. However, the determination is performed by the identification unit 124, and the region setting unit 121 is requested to divide the analysis region according to the determination result. It doesn't matter.

FIG. 6 is a diagram illustrating a state in which the analysis region is divided. Here, a case where the decoding reference positions are set at the four corners of the rectangular analysis region will be described as an example.
In the example shown in FIGS. 6A to 6D, an A4 document (original document ID is ID1), an A5 document (original document ID is ID2), and two A6 documents (original document ID is ID3). , ID4) are arranged as shown in FIG.

  In FIG. 6A, the analysis region [1] is set for the entire reading target. The original document IDs decoded from the partial images at the four decoding reference positions are ID1 at the upper left and lower left decoding reference positions, ID2 at the upper right decoding reference position, and those at the lower right decoding reference position. ID4. Therefore, the analysis area is divided as shown in FIG. 6B (see steps 502 and 503 in FIG. 5), and analysis areas [2-1] and [2-2] are newly set.

  In FIG. 6B, in the analysis area [2-1], all original document IDs decoded from the partial images at the four decoding reference positions are ID1. In the analysis area [2-2], the upper left and upper right decoding reference positions are ID2, the lower left decoding reference position is ID3, and the lower right decoding reference position is ID4. Here, since there is no original document ID that appears in both analysis areas [2-1] and [2-2], subdivision is not performed by changing the boundary of the analysis area (see step 504 in FIG. 5). . For the analysis area [2-1], since the original document IDs obtained from all the partial images match, the decoding process ends. On the other hand, for the analysis region [2-2], the analysis region is divided as shown in FIG. 6C (see steps 502 and 503 in FIG. 5), and the analysis regions [2-2-1], [2-2] 2-2-2] is set.

  In FIG. 6C, in the analysis area [2-2-1], the original document IDs decoded from the partial images at the four decoding reference positions are all ID2. In the analysis area [2-2-2], the upper left and lower left decoding reference positions are ID3, and the upper right and lower right decoding reference positions are ID4. Since there is no original document ID that appears in both analysis areas [2-2-1] and [2-2-2], subdivision is not performed by changing the boundary of the analysis area (see step 504 in FIG. 5). ). For the analysis region [2-2-1], since the original document IDs obtained from all the partial images match, the decoding process ends. On the other hand, the analysis region [2-2-2] is divided as shown in FIG. 6D (see steps 502 and 503 in FIG. 5), and a new analysis region [2-2-2-] is obtained. 1] and [2-2-2-2] are set.

  In FIG. 6D, in the analysis area [2-2-2-1], all original document IDs decoded from the partial images at the four decoding reference positions are ID3. In the analysis area [2-2-2-2], the original document IDs decoded from the partial images at the four decoding reference positions are all ID4. Since there is no original document ID that appears in both analysis areas [2-2-2-1] and [2-2-2-2], subdivision is not performed by changing the boundary of the analysis area (FIG. 5). Step 504). Since both the analysis areas [2-2-2-1] and [2-2-2-2] match the original document IDs obtained from all the partial images, the decoding process ends.

FIG. 7 is a diagram illustrating a method of subdividing by changing the boundary of the analysis region. Here, a case where the decoding reference positions are set at the four corners of the rectangular analysis region will be described as an example.
In the example shown in FIGS. 7A to 7C, the first document (original document ID is ID1) and the second document (original document ID is ID2) are arranged as shown in FIG. Yes.

  In FIG. 7A, the analysis region set for the entire reading target is divided into two equal parts, and the analysis regions are [1] and [2]. In this state, in the analysis area [1], all the original document IDs decoded from the partial images at the four decoding reference positions are ID1. In the analysis area [2], the upper left and lower left decoding reference positions are ID1, and the upper right and lower right decoding reference positions are ID2. Here, ID1 which is the original document ID of the first document exists in both analysis areas [1] and [2]. Therefore, it is necessary to change the boundary of the analysis region (see steps 504 and 505 in FIG. 5). As illustrated in FIG. 7B, the region setting unit 121 sets the analysis regions [1] and [2] again with a new boundary as a position that bisects the current analysis region [2]. In FIG. 7B, the boundaries of the analysis regions [1] and [2] in FIG. 7A are indicated by alternate long and short dash lines.

In FIG. 7B, in the analysis region [1], the upper left and lower left decoding reference positions are ID1, and the upper right and lower right decoding reference positions are ID2. In the analysis area [2], the original document IDs decoded from the partial images at the four decoding reference positions are all ID2. Therefore, since ID2 which is the original document ID of the second document exists in both analysis areas [1] and [2], it is necessary to change the boundary of the analysis area (see steps 504 and 505 in FIG. 5). . As shown in FIG. 7C, the region setting unit 121 sets an analysis region [1] using a position between the boundary in the state of FIG. 7A and the boundary in the state of FIG. 7B as a new boundary. , [2] is set again. In FIG. 7C, the boundaries of the analysis regions [1] and [2] in FIG. 7A are dashed lines, and the boundaries of the analysis regions [1] and [2] in FIG. It is shown with a dotted line.
Thereafter, by repeating the same operation, the boundaries of the analysis areas [1] and [2] approach the boundary between the first document and the second document.

  The analysis region dividing method described with reference to FIGS. 6 and 7 is merely an example, and is not limited to the above method. For example, when four decoding reference positions are set, it is recognized that the analysis area includes up to four recording media. Therefore, when the analysis area is divided, the original document is not only divided into two equal parts. It may be divided into three or four according to the number of identifications. Specifically, in the state of FIG. 6A, it can be seen that the analysis area [2] includes two original documents of ID2 and ID4, so that it is divided into two as shown in FIG. 6B. Instead, the prediction division may be performed as shown in FIG.

FIG. 8 is a flowchart for explaining the overall operation of the image processing apparatus 100.
Referring to FIG. 8, in the image processing apparatus 100, first, an image formed on a recording medium is read by the reading unit 110 (step 801). Then, the region setting unit 121 of the analysis unit 120 sets an analysis region for the read image (step 802). Next, the partial image selection unit 122 sets a decoding reference position in the analysis area and selects a partial image (step 803). Next, the decryption unit 123 decrypts the original document ID from the selected partial image (step 804). Next, the identifying unit 124 identifies the original document based on the decrypted original document ID (step 805).

Thereafter, it is determined whether or not the analysis region needs to be divided according to the identification result by the identification unit 124 (step 806). This determination may be performed by the area setting unit 121 or the identification unit 124 as described above. If it is determined that the analysis area needs to be divided, the area setting unit 121 divides the current analysis area and sets a new analysis area (step 807), and returns to step 803 to repeat the processing.
Of the above operations, the details of step 802 and step 807 are the operations shown in the flowchart of FIG. 5, and the contents thereof are as described above.

  By the way, when the code image is read by the reading unit 110, the code image may not be read correctly due to dirt on the recording medium, and the decoding of the original document ID by the decoding unit 123 may fail. If the original document ID cannot be decoded from the predetermined partial image, the partial image may be selected at a position close to the decoding reference position corresponding to the partial image and decoded again. Similarly, when the original document ID cannot be decoded from the newly selected partial image, the partial image is selected from a closer position. However, if positions adjacent in the same direction are selected sequentially from the decoding reference position, the position gradually moves away from the decoding reference position. Therefore, for example, after selecting a partial image from a position close to one side of the analysis region from the decoding reference position, the partial image is selected from a position close to the other side of the analysis region. A partial image is selected as far as possible from the original decoding reference position.

  As described above, in the present exemplary embodiment, the image processing apparatus 100 includes the reading unit 110 that reads an image, the reading unit 110 reads a recording medium on which the original document is recorded, and the analysis unit 120 performs processing on the read image. The document is identified. However, the present invention is not limited to such a configuration illustrated in FIG. For example, the reading unit 110 may not be provided in the image processing apparatus 100, and an image of a recording medium read by an external reading apparatus may be acquired, and the analysis unit 120 may process the acquired image.

  In addition, an image forming unit that forms and outputs an image on a predetermined recording medium according to the analysis result by the analysis unit 120 may be provided. That is, the original document read from the recording medium is specified as a result of the processing by the analysis unit 120. Therefore, the image processing apparatus 100 acquires electronic data (electronic document) of the original document from the document management server via, for example, a network. Then, instead of outputting the image read by the reading unit 110 and held in the holding unit 130, the image forming unit images the electronic document acquired from the document management server and forms it on a recording medium. The analysis unit 120 recognizes the number, size, orientation, arrangement, and the like of the recording medium on which the original document is recorded by setting the analysis area and decoding the original document ID. Therefore, the electronic document image acquired from the document management server can be processed and output so as to be an image similar to the image read by the reading unit 110, or individual electronic documents can be output individually.

<Unit code pattern>
Next, an example of a pattern image constituting a code image recorded on the recording medium to be read will be described.
FIG. 9 is a diagram illustrating an example of a unit code pattern.
In the example shown in the figure, dots are arranged by selecting three locations from a total of nine locations where dots can be arranged in three places in the vertical direction (hereinafter referred to as 3 × 3 places). In this case, there are 84 dot arrangement combinations of the unit code pattern (84 = ₉ C ₃ ) (where _m C _n = m! / {(Mn)! × n!}). When recording at 600 dpi, one dot size (square size) in FIG. 9 is 2 pixels in the vertical direction and 2 pixels in the horizontal direction (hereinafter referred to as 2 × 2 pixels), and is calculated to be 84.6 μm × 84. It becomes a 6 μm rectangle (however, the recorded toner image has a dot shape of about φ100 μm due to the influence of the xerographic process). Therefore, the size of the unit code pattern is 12 pixels vertically and 12 pixels horizontally (12 × 12 pixels), which is 0.5076 mm × 0.5076 mm.

Of the 84 types of unit code patterns, 64 types of unit code patterns (64 = 2 ⁶ = 6 bits) are used as information embedding codes (hereinafter referred to as information codes). Then, the remaining 20 types of unit code patterns are used as code blocks (described later) and as synchronization codes for rotation angle detection.
FIG. 10 is a diagram showing 84 dot arrangements that the unit code pattern of FIG. 9 can take, and FIG. 11 is a diagram showing examples (5 sets) of four types of unit code patterns that can be used as synchronization codes. In order to simplify the display, spaces between dots are omitted.

  As the synchronization code, there are four patterns for detecting the rotation angle of the code block every 90 degrees, but by using 20 patterns, five sets of synchronization codes can be created. The four unit code patterns used for the synchronization code are selected so as to be 90-degree rotationally symmetrical patterns. That is, if one of the four types of unit code patterns is embedded as a synchronization code at the time of image generation, the rotation angle of the code block (depending on which angle of the four types of unit code patterns is detected at the time of decoding) (Which direction of 0/90/180/270 degrees of the code block synchronized on the two-dimensional array is oriented) can be determined and corrected.

Note that the unit code pattern is not limited to the method of arranging dots at three of nine positions as shown in FIG. 10, and may be any number as long as it is smaller than nine. For example, if the dot is arranged at 4 out of 9 places, there are 126 combinations of the dot arrangement (126 = ₉ C ₄ ). Further, the number of places where dots can be arranged is not limited to nine (3 × 3), but may be other numbers, for example, four (2 × 2) or 16 (4 × 4).

<Code block>
FIG. 12 is a diagram illustrating an example of a code block.
The code block shown in FIG. 12 is configured by arranging 5 × 5 unit code patterns shown in FIG. The synchronization code shown in FIG. 11 is arranged at the upper left position of the code block. That is, any one of the synchronization codes shown in FIGS. 11A to 11E is selected, and one selected from the four unit code patterns included in the selected synchronization code is arranged at the upper left of the code block. The

In FIG. 12, the position code is arranged using four unit code patterns adjacent to the right side of the synchronization code and four unit code patterns adjacent to the lower side. The position code is a unit code pattern representing position information unique to the position on the recording medium on which the code pattern image is formed. In the present embodiment, an orthogonal coordinate (XY coordinate) is assumed on the surface of the recording medium, and the position is represented by the coordinate value. Therefore, the position code adjacent to the right side of the synchronization code is a position code obtained by encoding position information unique to the position in the X direction on the recording medium, and the position code adjacent to the lower side is the position in the Y direction on the recording medium. A position code obtained by encoding unique position information is arranged. Since the position codes in the X direction and the Y direction each use four unit code patterns, each can store information of 24 bits (6 bits × 4 pieces). Note that it is possible to use only 16 types of patterns as position codes without using 64 types (64 = 2 ⁶ ) patterns for embedding information. In this case, since the information amount per unit code pattern is 4 bits (16 = 2 ⁴ ), the position code is 16 bits (4 bits × 4 pieces) of information amount.

  In the remaining area of the code block, an information code capable of describing arbitrary recording information is arranged. Since 16 unit code patterns (4 × 4) can be arranged in this area, information of 96 bits (6 bits / unit code pattern × 16) can be recorded. As information recorded in this information code, an original document ID for identifying the original document is described. Since the unit code pattern of the present embodiment is a multi-level code, errors that occur during reading and the like also occur in units of the unit code pattern. Therefore, it is desirable that the error correction code be a system that can perform error correction in units of blocks. If an RS code (Reed-Solomon Code), which is a known block error correction code system, is used, the block length of the RS code can be set to 6 bits, which is the information amount of the unit code pattern. In this case, the code length of the RS code is 16 blocks (= 96 bits / 6 bits / block). For example, if the correction capability of 3 blocks is provided, the code length of the RS code is 10 blocks (= 16 blocks−3). Block x 2). In this case, as the recording information, information of 60 bits (= 6 bits / block × 10 blocks) can be embedded in the information code area.

As described above, the configuration example of the code image using the ₉ C ₃ unit code pattern has been described, but the code image used in the present embodiment is not limited to the above. For example, a code image configured using a slash pattern (/) or a dot pattern having a different size may be applied, or an existing QR code, a two-dimensional barcode, or the like may be applied.

It is a figure which shows the function structural example of the reading apparatus of this embodiment. It is a figure which shows the example which set the 2 angle | corner located on the diagonal of an analysis area | region as a decoding reference | standard position. It is a figure which shows the example which set four corners of the analysis area as a decoding reference position. It is a figure which shows the example which set the decoding reference position based on the reference point fixedly set with respect to the reading area. It is a flowchart explaining operation | movement of the area | region setting part of this embodiment. It is a figure which illustrates a mode that the area | region setting part of this embodiment divides | segments an analysis area | region. It is a figure which shows the method of changing and dividing | segmenting the boundary of the analysis area | region in this embodiment. 3 is a flowchart illustrating an overall operation of the image processing apparatus according to the present embodiment. It is a figure which shows the example of the unit code pattern used by this embodiment. It is a figure which shows 84 kinds of dot arrangement | positioning which the unit code pattern of FIG. 9 can take. It is a figure which shows the example (5 sets) of four types of unit code patterns which can be used as a synchronous code. It is a figure which shows the example of the code block used by this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Image processing apparatus 110 ... Reading part 120 ... Analysis part 121 ... Area setting part 122 ... Partial image selection part 123 ... Decoding part 124 ... Identification part 130 ... Holding part

Claims (12)

An area setting unit that sets an analysis area to be analyzed for an image read from a recording medium;
A partial image selection unit that sets a plurality of decoding reference positions with a predetermined interval or more in the analysis region, and selects a partial image at the decoding reference position;
A decoding unit for decoding the identification information of the recording medium from the partial image;
An image processing apparatus comprising: an identification unit that identifies the recording medium based on the decoded identification information.   The region setting unit divides the analysis region and sets a plurality of new analysis regions when a plurality of recording media are identified by the identification unit for one analysis region. The image processing apparatus according to claim 1.   The image processing apparatus according to claim 2, wherein the region setting unit divides the analysis region so that a long side of the rectangular analysis region is divided into two equal parts.   When the identification information of the same recording medium is decoded from the partial images at the decoding reference position set in the plurality of analysis areas, the area setting unit changes the boundaries of the plurality of analysis areas again. The image processing apparatus according to claim 2, wherein the image processing apparatus is divided.   The image processing apparatus according to claim 1, wherein the partial image selection unit uses two corners positioned on a predetermined diagonal in the rectangular analysis region as the decoding reference position.   The image processing apparatus according to claim 1, wherein the partial image selection unit sets four corners in the rectangular analysis region as the decoding reference position.   The partial image selection unit sets a position of a reference point included in the analysis area as a reference decoding position among reference points set for a reading area that can be read by a reading device of the recording medium. The image processing apparatus according to claim 1, wherein: Read the image formed on the recording medium,
For the scanned image, set the analysis area to be analyzed,
In the analysis area, set a plurality of decoding reference positions with a certain interval or more, select a partial image of the decoding reference position,
Decoding the recording medium identification information from the partial image;
Identifying the recording medium based on the decrypted identification information;
An identification method, wherein when a plurality of recording media are identified for one analysis area, the analysis area is divided to set a plurality of new analysis areas.   When identification information of the same recording medium is decoded from the partial image at the decoding reference position set in a plurality of analysis areas, the boundary of the plurality of analysis areas is changed and divided again. The identification method according to claim 8. On the computer,
A function for setting an analysis area to be analyzed for an image read from a recording medium;
In the analysis region, a function of setting a plurality of decoding reference positions with a certain interval or more, and selecting a partial image at the decoding reference position;
A function of decoding identification information of the recording medium from the partial image;
A program for realizing the function of identifying the recording medium based on the decrypted identification information.   As a function of setting the analysis area, when a plurality of recording media are identified for one analysis area, the computer executes processing for dividing the analysis area and setting a plurality of new analysis areas The program according to claim 10, wherein the program is executed.   As a function of setting the analysis area, when the identification information of the same recording medium is decoded from the partial image at the decoding reference position set in the plurality of analysis areas, the boundary of the plurality of analysis areas is changed. The program according to claim 10, further causing the computer to execute a process of dividing again.

Images