JP2019068406A - INFORMATION PROCESSING APPARATUS, METHOD, AND PROGRAM - Google Patents

Abstract

To accurately determine whether a file is a searchable file without using a command for notifying that the file is a searchable file. According to the present invention, first extracting means for extracting a character area in an image object included in a file, a character area extracted by the first extracting means, and a character object included in the file are drawn. Determination means for determining whether or not the file is a searchable file including an image and a character recognition result corresponding to the image, based on a positional relationship with the region, and the first determination Means for executing character recognition processing on the image object in response to determining that the file is not a searchable file, and generating a file including a result of the character recognition processing. This is a characteristic information processing device. [Selection diagram] Figure 4

Description

  The present invention relates to an information processing apparatus, method, and program for recognizing a character string in an image in a file and generating a searchable file.

  Conventionally, there is software for creating a searchable PDF file (hereinafter referred to as SPDF file) that can search for character strings. An example of the SPDF file is shown in FIG. The SPDF file 201 includes a scan image 202. Furthermore, in the SPDF file 201, a transparent character string is embedded according to the position of the character image in the scan image so as to overlap the scan image. For example, the character code of the character string is described in a PDF (Portable Document Format) file so that the transparent character string “200,000” is disposed on the front or back of the character image 203 in the scan image. Also, although not shown, a transparent character string character code corresponding to all character images other than the character image 203 in the scan image is also described in the PDF file. Although it is not possible to search for a character string using only the character image in the scanned image, the character code obtained as a result of character recognition processing is embedded as a transparent character string at a position corresponding to the character image. Enables searching of strings without changing the appearance. As described above, software that creates an SPDF file performs character recognition processing on a scanned image, and adds the character code obtained as a result to the PDF file as a transparent character string.

  The PC on which the software for creating the SPDF file is installed receives the scanned image created by the copying machine or software, or the PDF file including the image, and creates the SPDF file using the received data. However, for example, depending on the copying machine, it is possible for the copying machine itself to create the SPDF file, and the input data to the PC that executes the software for creating the SPDF file is created by an apparatus other than the PC including the copying machine SPDF files may be input. In the present specification, “input data” means data of the creation source when creating the SPDF file, and the SPDF file is created based on the input data. As input data, for example, a scanned image created by a copying machine, or a PDF file or an SPDF file including an image such as a scanned image can be considered.

  Here, since the file extension of SPDF is “pdf” as well as the file extension of PDF that is not searchable, it is determined whether the PDF file of the input data is an SPDF file based on the file extension. The problem arises that you can not

  As one method for solving this problem, Patent Document 1 determines whether the PDF file is an SPDF file by embedding a command for notifying that the file is a searchable file in the file. Technology that makes it possible to

JP, 2011-010232, A

  However, existing software and copiers that create SPDF files do not have the function as in Patent Document 1 that embeds a command for notifying that they are SPDF files in the file. The reason is that in the definition of the PDF format, there is no definition for identifying whether it is an SPDF file or not. About the PDF file created and sent using the existing software etc. which do not have the function to embed such a command in a file, the PDF file of the input data is the SPDF file on the device side where the PDF file is input It can not be determined.

  Also, it is conceivable to simply determine whether or not the input data is an SPDF file based on whether or not there is a transparent character string in the input data, but for the following reasons, the determination criterion is appropriate. Absent. FIG. 3 is a view showing an example in which a transparent character string unrelated to the content of the image is embedded. Depending on the operation of the user, information such as an ID for identifying the user may be embedded in the image as a transparent character string 302. As described above, since there is a case in which a transparent character string not related to the character image in the scanned image exists in the file, the input data is the SPDF file based on whether or not the transparent character string exists in the input data. It is not appropriate in terms of accuracy to determine whether or not.

  Therefore, in view of the above problems, it is an object of the present invention to determine with high accuracy whether a file is a searchable file without using a command for notifying that the file is a searchable file.

  According to the present invention, a first extraction unit for extracting a character area in an image object included in a file, a character area extracted by the first extraction unit, and an area in which a character object included in the file is drawn A first determination unit that determines whether the file is a searchable file including an image and a result of character recognition corresponding to the image based on a positional relationship; and the first determination unit Information characterized by performing character recognition processing on the image object in response to the determination that the file is not a searchable file, and generating a file including the result of the character recognition processing It is a processing device.

  According to the present invention, it is possible to determine with high accuracy whether a file is a searchable file without using a command for notifying that the file is a searchable file.

FIG. 1 is a block diagram showing the configuration of a system etc. in a first embodiment. An example of a SPDF file. An example in which a transparent string unrelated to the content of the image is embedded. 10 is a flowchart of SPDF file creation processing accompanied by PDF file determination processing in the first embodiment. 10 is a flowchart of processing in Embodiment 2. An example of a dialog asking if you want to recreate the SPDF file. 10 is a flowchart of processing in a third embodiment. An example of a screen to select whether to delete the transparent string. 10 is a flowchart of processing in a fourth embodiment. An example of a screen to set options when creating an SPDF file. 16 is a flowchart of processing in a fifth embodiment. Explanatory drawing of a recognition cell. 16 shows an example of a screen displayed in the search process in the sixth embodiment. 16 is a flowchart of search control processing in a sixth embodiment.

Example 1
<About the system configuration>
Hereinafter, the configuration of the system in the present embodiment will be described with reference to FIG.

  FIG. 1A is a block diagram showing a system in the present embodiment. As shown, the system 100 includes an image formable copying machine 110 and an information processing apparatus 120. The copying machine 110 and the information processing apparatus 120 are communicably connected in a wired or wireless manner, and can mutually transmit and receive data.

  FIG. 1B is a block diagram showing a functional configuration of the copying machine 110. As shown in FIG. The copying machine 110 includes a scanner unit 111, a transmission / reception unit 112, a printer unit 113, and a control unit 114.

  FIG. 1C is a block diagram showing a functional configuration of the information processing apparatus 120. The information processing apparatus 120 includes a transmission / reception unit 121, a storage unit 122, a control unit 123, a display unit 124, and a reception unit 125. The information processing apparatus 120 internally has a CPU, a storage medium such as a ROM and a hard disk, and a temporary storage medium such as a RAM, and a program stored in the ROM is loaded into the RAM, and the CPU Run the loaded program. Thereby, each configuration shown in FIG. 1C is realized, and the processing by each configuration is executed. The receiving unit 125 generally includes a keyboard and a mouse, but the present invention is not limited to this. Further, although the display unit 124 and the reception unit 125 are separately configured here, the display unit 124 and the reception unit 125 may be integrally realized by, for example, a touch panel or the like.

<Flow from document scanning to creation of SPDF file>
The flow of scanning a document by the copying machine 110 and creating an SPDF file by the information processing apparatus 120 will be described below. When the scanner unit 111 of the copier 110 scans a document, a scan image (also referred to as scan image data) is created. The transmission / reception unit 112 transmits the created scan image to the information processing apparatus 120. Then, the transmission / reception unit 121 of the information processing apparatus 120 receives the scan image, and the control unit 123 stores the received scan image in the storage unit 122.

  The user selects one scan image from the one or more scan images stored in the storage unit 122 via the reception unit 125. Then, the control unit 123 displays the scanned image on the display unit 124.

  The user instructs creation of the SPDF file based on the scan image displayed on the display unit 124 via the reception unit 125. Then, the control unit 123 executes the following processing, ie, area division shown in (1) to (5), character recognition shown in (6), and embedding of a transparent character string shown in (7), on the scanned image. By doing this, an SPDF file is created, and the created SPDF file is stored in the storage unit 122.

<About SPDF file creation processing based on scanned image>
The process of creating the SPDF file based on the scanned image will be described in detail below.

(1) The binarization control unit 123 binarizes the scan image to obtain a binary image consisting of only black pixels and white pixels. By binarization, a pixel having a density value equal to or higher than a predetermined threshold value in the scan image is a black pixel, and a pixel having a density value lower than the predetermined threshold value is a white pixel. Although the following description will be made on the assumption that the scan image is 100 DPI, it goes without saying that the scan image is not limited to this resolution.

(2) The black pixel block detection control unit 123 tracks the outlines of the black pixels connected in eight connections with the binary image, thereby continuously displaying black pixel blocks in any of eight directions. Detect (set as black pixel block). The 8-connected means that pixels of the same color (black in this case) are continuous in any of eight directions: upper left, left, lower left, lower, lower right, upper right, upper right. On the other hand, 4-connected means that pixels of the same color are continuous in any of the four directions of left, lower, right and upper. In this embodiment, a single black pixel which is not a black pixel in any of eight adjacent pixels present in eight directions is not detected as a black pixel block. On the other hand, a black pixel in which a black pixel exists in any one of eight adjacent pixels existing in eight directions is detected as a black pixel block together with the adjacent black pixel. Reference numeral 1201 in FIG. 12 denotes an example of the black pixel block detected by the control unit 123.

  The control unit 123 also derives position information of the circumscribed rectangle of the detected black pixel block, specifically, the X coordinate and Y coordinate of each of the four vertices of the circumscribed rectangle. The X axis extends in the right direction, and the Y axis extends in the lower direction. Reference numeral 1202 in FIG. 12 denotes a circumscribed rectangle of the black pixel block 1201. Incidentally, when expressed as “rectangle” in the present specification, unless it is expressed as a “rectangle”, a diagonal rectangle is not included, and all the four sides represent a rectangle parallel to either the X axis or the Y axis.

(3) The detection control unit 123 of the table area determines whether all the three conditions shown below are satisfied for each of the detected black pixel groups, and the black pixel group satisfying all the three conditions is set as the frame line of the table. It is determined that the black pixel block to be configured. The three conditions are described below.

  The first condition is that the width of the circumscribed rectangle of the black pixel block is equal to or greater than a predetermined threshold, and the height of the circumscribed rectangle is equal to or greater than the predetermined threshold. In the present specification, “width” refers to the length in the X direction, and “height” refers to the length in the Y direction. In this embodiment, it is determined whether the width and the height are both 0.25 cm or more, which corresponds to 100 pixels.

  The second condition is that the filling factor of the black pixel block inside the circumscribed rectangle is equal to or less than a predetermined threshold. In this embodiment, it is determined whether the proportion of black pixel blocks in the circumscribed rectangle is 20% or less.

  The third condition is that the difference between the maximum width of the black pixel block and the width of the circumscribed rectangle and the difference between the maximum height of the black pixel block and the height of the circumscribed rectangle are both small. Specifically, the difference between the maximum width of the black pixel block and the width of the circumscribed rectangle is less than or equal to a predetermined threshold, and the difference between the maximum height of the black pixel block and the height of the circumscribed rectangle is predetermined It is below the threshold. In the present embodiment, whether the difference between the maximum width of the black pixel block and the width of the circumscribed rectangle and the difference between the maximum height of the black pixel block and the height of the circumscribed rectangle are both 10 pixels or less judge.

  The control unit 123 determines whether each of the black pixel blocks satisfies the first to third conditions described above to determine whether it is a black pixel block forming a frame of the table, The storage unit 122 stores the position information of the circumscribed rectangle of the black pixel block constituting the frame line of The area of the circumscribed rectangle having the position information stored in this manner is called a table area. In the case shown in FIG. 12, as a result of the detection of the front area, the black pixel block 1201 is determined to be a black pixel block that constitutes the border of the table, and the area of the circumscribed rectangle 1202 is detected as the front area. I assume. In the present embodiment, the black pixel block satisfying all of the above-described first to third conditions is determined as the black pixel block forming the frame of the table, but the determination condition is not limited to this. For example, a black pixel block satisfying at least one of the first to third conditions may be determined as a black pixel block constituting a frame line of the table.

(4) Identification Control Unit of Recognition Cell The recognition control unit 123 identifies the recognition cell in the front area. Here, the "recognition cell" is a circumscribed rectangle of a white pixel block inside the front area. In order to specify the recognition cell, it is necessary to detect a white pixel block by tracking the outline of the white pixel inside the front area. Then, the control unit 123 determines whether the following three conditions are satisfied for each of the detected white pixel blocks, and specifies the circumscribed rectangle of the white pixel block satisfying all the three conditions as a recognition cell.

  The first condition is that the width of the circumscribed rectangle of the white pixel block is equal to or greater than a predetermined threshold, and the height of the circumscribed rectangle is equal to or greater than the predetermined threshold. In this embodiment, it is determined whether the width and height are both 20 pixels or more.

  The second condition is that the filling factor of the black pixel block inside the circumscribed rectangle is equal to or less than a predetermined threshold. In this embodiment, it is determined whether the proportion of black pixel blocks in the circumscribed rectangle is 20% or less.

  The third condition is that the difference between the maximum width of the white pixel block and the width of the circumscribed rectangle and the difference between the maximum height of the white pixel block and the height of the circumscribed rectangle are both small. Specifically, the difference between the maximum width of the white pixel block and the width of the circumscribed rectangle is less than or equal to a predetermined threshold, and the difference between the maximum height of the white pixel block and the height of the circumscribed rectangle is predetermined It is below the threshold. In the present embodiment, the difference between the maximum width of the white pixel block and the width of the circumscribed rectangle and the difference between the maximum height of the white pixel block and the height of the circumscribed rectangle are both 5 or less. Determine if

  Reference numerals 1203 and 1204 in FIG. 12 denote recognition cells identified by the control unit 123. The control unit 123 stores the position information of the identified recognition cell in the storage unit 122.

  In the present embodiment, the circumscribed rectangle of the white pixel block satisfying all of the above-described first to third conditions is specified as the recognition cell, but the determination condition is not limited to this. For example, a circumscribed rectangle of a white pixel block satisfying at least one of the first to third conditions may be specified as a recognition cell.

(5) The specification control unit 123 of the character area in the recognition cell determines whether or not there is a black pixel block surrounded by a white pixel block inscribed in each recognition cell inside each recognition cell. Then, when it is determined that there is a black pixel block, circumscribed rectangles for all the black pixel blocks determined to be present are set.

  Furthermore, when a plurality of circumscribed rectangles are set in one recognition cell, the control unit 123 determines whether the distance between the circumscribed rectangles is equal to or less than a predetermined threshold. Specifically, the control unit 123 selects circumscribed rectangles one by one and detects a circumscribed rectangle whose distance from the selected circumscribed rectangle is equal to or less than a predetermined threshold. For example, it is determined whether the distance between circumscribed rectangles is 20 pixels or less.

  Furthermore, when such a circumscribed rectangle is detected, the control unit 123 integrates the detected circumscribed rectangle and the selected circumscribed rectangle. That is, the control unit 123 sets a new circumscribed rectangle circumscribing the both circumscribed rectangles, and deletes the selected circumscribed rectangle and the detected circumscribed rectangle.

  After setting of a new circumscribed rectangle and deletion of two circumscribed rectangles are completed, the control unit 123 selects the circumscribed rectangles in the recognition cell one by one from the beginning, and the distance between each other is less than a predetermined threshold. Integrate the circumscribed rectangles of Repeat the above processing. That is, integration of circumscribed rectangles is repeated until there is no circumscribed rectangle in which the distance between each other is equal to or less than a predetermined threshold.

  As described above, in this embodiment, the circumscribed rectangles present inside one recognition cell are integrated, but the circumscribed rectangles straddling the recognition cell are not integrated.

  The circumscribed rectangle that has been set up after the above processing is called a character area (or text block). The above processing is called identification of a character area in a recognition cell. The control unit 123 stores the position information of the character area present inside the recognition cell in the storage unit 122 in association with the recognition cell.

  In the case of FIG. 12, reference numerals 1205 and 1206 indicate character areas. The position information of the character area 1205 is stored in the storage unit 122 in association with the recognition cell 1203. The position information of the character area 1206 is stored in the storage unit 122 in association with the recognition cell 1204.

(6) The character recognition control unit 123 performs character recognition on each character area to obtain recognized characters corresponding to each character area. Here, "recognized character" is a character code obtained by character recognition of an original character (character image in a scanned image), and the recognized character is embedded in the PDF file as a transparent character string. The recognized characters acquired by character recognition are stored in the storage unit 122 in association with the corresponding character area. By doing so, the recognition character will also be associated with the recognition cell previously associated with the character area. If character recognition is not performed or character recognition fails, there is no recognized character associated with the character area.

  Moreover, when performing character recognition, a recognition rate may be acquired. The recognition rate is an index indicating whether the character has been correctly recognized, and is stored in the storage unit 122 in association with the recognized character.

(7) When the input data is an image, the transparent character string embedding control unit 123 first creates a PDF file newly and stores a scan image in it, while when the input data is a PDF file, Delete all the transparent strings contained in the PDF file. Thereafter, the control unit 123 adds the recognized character acquired by the above-described (6) character recognition to the PDF file as a transparent character string at the position of the corresponding character area.

  Here, although the case where the control unit 123 of the information processing apparatus 120 executes the above-described processes (1) to (7) has been described, these processes are executed by the control unit 114 of the copying machine 110. I don't care. In that case, the copying machine 110 will create an SPDF file.

<About SPDF file creation processing with PDF file determination processing>
Hereinafter, SPDF file creation processing accompanied by PDF file determination processing for determining whether the PDF file of input data is an SPDF file, which is executed when the user instructs creation of an SPDF file based on input data, will be described using FIG. .

  In step S401, when the input data is a PDF file, the control unit 123 determines whether the PDF file includes a scanned image by determining whether the PDF file includes an image equivalent to the page size. Do. If the PDF file includes an image of a page size, it is determined that the PDF file includes a scan image, and the process advances to step S404. On the other hand, when the PDF file does not include the image of the page size, it is determined that the PDF file does not include the scan image, and the process proceeds to step S402. Specifically, in the present embodiment, in step S401, the width x [mm] and height y [mm] of the page are first acquired from the PDF file, and then the width is x -5 [mm] or more. It is determined whether there is an image having a height of y-5 [mm] or more in the PDF file. Here, 5 is an allowable error. As described above, in this step, it is considered that a margin may be included when creating a PDF file from a scanned image. That is, even if the page size and the image size do not completely match, if there is an image having a size close to the page size to some extent, it is determined that the PDF file includes the scan image. Although the allowable error is set to 5 [mm] in this embodiment, this value may be changed as appropriate depending on the scanning environment.

  First, the case where the image corresponding to the page size is not included in the PDF file (in the case of NO at step S401) will be described. In this case, in step S402, the control unit 123 determines that the PDF file of the input data is not an SPDF file. Next, in step S403, the control unit 123 executes an OCR process on the input data, and embeds the character code obtained as a result as a transparent character string, thereby creating a SPDF file, and storing the created SPDF file Save to 122

  Next, the case where the image of the page size is included in the PDF file (YES in step S401) will be described. In this case, in step S404, the control unit 123 extracts a character area by performing area division on the image. The total number of character areas obtained in this step is N.

  In step S405, the control unit 123 initializes a parameter X for counting character areas whose positions and sizes match the transparent character string, and sets the parameter X to zero.

  In step S406, the control unit 123 focuses on one of the unchecked character areas (selection of a focused character area).

  In step S407, the control unit 123 determines whether there is a transparent character string whose position and size match those of the target character area. In this step, the positional relationship between the character area in the image object and the area where the character object (specifically, a transparent character string) is drawn is seen. If the determination result in step S407 is true, the process proceeds to step S408, while if the determination result is false, the process proceeds to step S409. In this step, it is also possible to determine that the position and size of the target character area match the position and size of the transparent character string even if the position and size do not completely match, in consideration of scan deviations and the like. . For example, even if there is a difference in the range of about ± 1 mm, it may be determined that they match.

  If YES in step S407, the control unit 123 increments X in step S408, and proceeds to step S409. On the other hand, if NO in step S407, the process proceeds to step S409 without incrementing X.

  In step S409, the control unit 123 determines whether all the character areas have been checked. If the determination result in step S409 is true, the process proceeds to step S410, while if the determination result is false, the process returns to step S406.

  As described above, in this embodiment, in steps S405 to S409, it is counted how many positions and sizes of the character areas match the transparent character string.

  In step S410, the control unit 123 determines whether the following formula (1) is satisfied. If the determination result in step S410 is true, the process proceeds to step S411, while if the determination result is false, the process proceeds to step S413.

In Equation (1), S is a threshold value for determining whether the input data is a SPDF file, and the input data is a threshold when the number of character areas whose position and size match the transparent character string is greater than This is a threshold for determining an SPDF file. In the present embodiment, S is set to 0.9. Setting S to 0.9 means that the input data is determined to be an SPDF file if the ratio of the character area whose position and size match the transparent character string among the character areas is greater than 90%. means. The reason why S is set to 0.9 instead of 1.0 is because it takes into consideration that characters can not always be recognized with a recognition rate of 100% because of a decrease in scan accuracy according to the environment, etc. is there. Of course, the value of S may be changed according to the environment.

  If equation (1) is satisfied (YES in step S410), in step S411, control unit 123 determines that the input data is a SPDF file. Next, in step S412, the control unit 123 stores the SPDF file of the input data as it is in the storage unit 122 without recreating the SPDF file, and the series of processing ends.

  On the other hand, when the equation (1) is not satisfied (NO in step S410), in step S413, the control unit 123 determines that the input data is not an SPDF file. Next, in step S414, the control unit 123 executes an OCR process on the input data, and embeds the character code acquired as a result of the OCR process as a transparent character string to create a SPDF file, and the created SPDF file It is stored in the storage unit 122. The above is the contents of the SPDF file creation process accompanied by the PDF file determination process in the present embodiment.

  According to this embodiment, it is possible to determine with high accuracy whether the PDF file of the input data is an SPDF file without using a command for notifying that the file is a searchable file. If the input data is already an SPDF file, the SPDF file is stored as it is in the storage unit and the SPDF file is not re-created. Therefore, unnecessary processing can be reduced.

Example 2
In the present embodiment, when it is determined that the input data is an SPDF file (YES in step S410 → step S411), the user is made to select whether or not to re-create the SPDF file. In the following, differences from the above-described embodiment will be mainly described, and the description of the same contents as the above-described embodiment will be appropriately omitted.

  Even if the input data is already an SPDF file, the character recognition accuracy may be improved by re-doing the character recognition in the information processing apparatus 120. For example, if the character recognition engine installed in the information processing apparatus 120 is excellent, the character recognition accuracy may be improved by performing the character recognition again by the information processing apparatus 120. On the other hand, if the character recognition engine that originally created the SPDF file is superior to the character recognition engine installed in the information processing apparatus 120, the accuracy of the character recognition improves even if the information processing apparatus 120 re-executes character recognition There is nothing to do. In addition, since character recognition requires a certain amount of time for processing, it is not preferable to constantly re-create the SPDF file from the viewpoint of performance. As described above, there is an advantage and disadvantage in re-creating the SPDF file, and the merits and demerits also depend on the user environment, so the user can select whether or not to re-create the SPDF file.

  Hereinafter, the process in the present embodiment will be described with reference to FIG.

  If it is determined in step S411 that the input data is an SPDF file, in step S501, the control unit 123 displays on the display unit 124 a dialog for causing the user to select whether or not to re-create the SPDF file. FIG. 6 is a diagram showing an example of the dialog displayed in this step. The dialog 601 has a message 602 asking whether to re-create the SPDF file. The dialog 601 also includes a Yes button 603 pressed by the user when creating the SPDF file, and a No button 604 pressed by the user when the SPDF file is not created.

  In step S502, the control unit 123 determines whether the Yes button 603 of the dialog 601 is pressed. If the determination result in step S502 is true, the process proceeds to step S503, while if the determination result is false (ie, the No button 604 is pressed), the process proceeds to step S412.

  When the YES button 603 is pressed (YES in step S502), in step S503, the control unit 123 re-creates the SPDF file, and saves the re-created SPDF file in the saving unit 122.

  According to the present embodiment, when the input data is determined to be an SPDF file, it is possible to allow the user to select whether to re-create the SPDF file.

[Example 3]
In this embodiment, when the SPDF file is re-created, the transparent character string irrelevant to the content of the image is left without being deleted.

  When recreating the SPDF file based on the SPDF file of the input data, normally, the originally embedded transparent character string is once deleted, and the newly acquired character code is embedded as the transparent character string. However, when such a process is performed on an SPDF file having a transparent character string unrelated to the content of the image as shown in FIG. 3, the transparent character string will be deleted and disappear. Therefore, in the present embodiment, when the transparent character string is once deleted, the transparent character string unrelated to the content of the image is not deleted. Hereinafter, the process of creating the SPDF file again in the present embodiment will be described with reference to FIG.

  First, in step S701, the control unit 123 performs area division and character recognition on an image of input data, and stores information obtained as a result in the storage unit 122.

  In step S702, the control unit 123 focuses on one unchecked transparent character string (selection of a target transparent character string).

  In step S703, the control unit 123 determines whether the position and size of the target transparent character string match any position and size of the character area acquired in step S701. If the determination result in step S703 is true, the process proceeds to step S704, while if the determination result is false, the process proceeds to step S706. In this step, it is determined that the position and the size of the target transparent character string coincide with any position and the size of the character area even if the position and the size do not completely match, considering the shift of the scan, etc. It is good.

  If the position and size of the target transparent character string match one of the character areas (YES in step S703), in step S704, the control unit 123 determines that the target transparent character string is a transparent character string related to the content of the image, that is, the search Determined to be a transparent string for Next, in step S705, the control unit 123 deletes the target transparent character string, and proceeds to step S707.

  On the other hand, when there is no character area having a position and size matching the position and size of the target transparent character string (NO in step S703), in step S706, the control unit 123 determines that the target transparent character string is the content of the image. It is judged as a transparent string unrelated to. Then, it progresses to step S707.

  In step S 707, the control unit 123 determines whether all the transparent character strings have been checked. If the determination result in step S707 is true, the process proceeds to step S708, while if the determination result is false, the process returns to step S702.

  In step S 708, the control unit 123 adds the character code acquired by character recognition as a transparent character string. The above is the contents of the process of creating the SPDF file again in the present embodiment.

  According to this embodiment, when the SPDF file is re-created, it is possible to leave the transparent character string unrelated to the content of the image without deleting it.

Example 4
In this embodiment, it is possible for the user to select whether or not the transparent character string irrelevant to the content of the image is left without being deleted.

  FIG. 8 is a diagram showing an example of a prompt screen displayed on the display unit 124 by the control unit 123 when the user selects whether to delete a transparent character string unrelated to the content of the image. In the case of FIG. 8, the control unit 123 detects the transparent character string 302 irrelevant to the content of the image and displays the circumscribed rectangle 801 to emphasize the transparent character string 302. Further, although not shown, the user can visually recognize the transparent character string 302 by temporarily displaying the transparent character string 302 as translucent. Furthermore, a check box 802 is displayed near the transparent character string 302. If the user checks this check box 802, the transparent string 302 will be deleted when the SPDF file is recreated.

<About screen creation process>
Hereinafter, the process of creating the screen as illustrated in FIG. 8 in the present embodiment will be described with reference to FIG.

  In the screen creation processing in the present embodiment, after it is determined in step S706 that the target transparent character string is a transparent character string unrelated to the content of the image, the processing proceeds to step S901. Then, in step S901, the control unit 123 displays the circumscribed rectangle corresponding to the target transparent character string and the check box on the display unit 124, and displays the target transparent character string as semitransparent.

<About SPDF file creation process>
Hereinafter, the SPDF file creation processing in the present embodiment will be described using FIG. 9 (b).

  In the SPDF file creation process in the present embodiment, after it is determined in step S706 that the target transparent character string is a transparent character string unrelated to the content of the image, the process proceeds to step S902. Then, in step S902, the control unit 123 determines whether the check box corresponding to the target transparent character string is checked. If the determination result in step S902 is true, the process proceeds to step S705, and while the target transparent character string is deleted, the process proceeds to step S707 if the determination result is false. In this case, the target transparent character string is not deleted. That is, in this embodiment, the transparent character string irrelevant to the content of the image is not necessarily deleted, but the transparent character string is deleted according to the user's selection.

  The present embodiment allows the user to select whether or not to keep transparent strings irrelevant to the content of the image without deleting them.

[Example 5]
In this embodiment, only the character string having a high recognition rate is replaced with the transparent character string when the SPDF file is re-created. As described above, when the SPDF file is re-created, the existing transparent character string is once deleted, then character recognition is performed, and the transparent character string is added. However, when the recognition rate is low, there is a high possibility that the recognition accuracy will be lower than when the existing transparent character string is acquired. Therefore, in the present embodiment, only the character string whose recognition rate is equal to or more than the threshold value is replaced with the transparent character string.

  FIG. 10 is a diagram showing an example of a dialog for setting options when creating an SPDF file. The option setting dialog 1001 has a check box 1004 for checking when replacing all transparent characters, and a check box 1005 for checking when replacing only a character string with a high recognition rate. The user checks either the check box 1004 or the check box 1005.

<About SPDF file creation process>
Hereinafter, the SPDF file creation process executed when the check box 1005 in the option setting dialog 1001 is checked in the present embodiment will be described using FIG.

  In the present embodiment, the process proceeds to step S1101 after step S704, and in step S1101 the control unit 123 determines whether the recognition rate of the recognized character corresponding to the target transparent character string is equal to or more than a predetermined threshold. If the determination result in step S1101 is true, the process proceeds to step S705 to delete the target transparent character string, while if the determination result is false, the process proceeds to step S707. As described above, in this step, in order to replace only a character string having a high recognition rate with a transparent character string in the subsequent step S1102, an existing transparent character string having a high recognition rate is deleted in advance.

  Further, in the present embodiment, the process proceeds to step S1102 after step S707, and in step S1102, the control unit 123 adds, among the recognized characters, characters whose recognition rate is equal to or more than a predetermined threshold as a transparent character string. The process ends. The above is the contents of the SPDF file creation process in this embodiment.

  According to this embodiment, when the SPDF file is re-created, only the character string having a high recognition rate can be replaced with the transparent character string.

[Example 6]
In this embodiment, an example of a method of utilizing the SPDF file generated by the method described in the above-described embodiment will be described. In the present embodiment, a mechanism is provided for searching in detail each file stored in the storage unit 122 or the like. Also, a mechanism for printing the file found by the search using the copying machine 110 is provided. FIGS. 13A and 13B illustrate examples of screens displayed on the display unit 124 of the information processing apparatus 120. FIG. FIG. 13A is a view showing an example of a screen for inputting a search word, and FIG. 13B is a view showing an example of a screen showing a list of search results. The screens illustrated in FIGS. 13A and 13B are screens provided by a document management application that manages the generated SPDF file, a document file in the computer, and the like. The user can perform file attribute search, full-text search, concept search and the like through the screens of FIGS. 13 (a) and 13 (b).

  In this embodiment, full-text search of files including SPDF will be described. An area 1301 is an area for inputting a search keyword. The user can enter a keyword that he / she wants to search in the area 1301. The search method check box is a check box for specifying whether each keyword is to be searched by AND or OR. The Search key 1302 is a key pressed when performing a search.

  FIG. 13B is a screen showing an example of the search result. Here, three files including two search keywords of “Kawasaki” and “BlackBlue” are found and illustrated in the list. Reference numeral 1303 indicates that the SPDF file in FIG. 2 is specified among the three found files. The user can open and print the file found by the search through the screen of FIG. 13 (b).

  A specific control method will be described with reference to FIG. The flowchart of FIG. 14 is executed according to the user operation of file search being accepted via the management screen of the document management application.

  In step S1401, the control unit 123 receives an input of a search keyword via the reception unit 125. If it is detected that the Search key 1302 has been pressed after receiving the search keyword input, the process proceeds to step S1402.

  In step S1402, the control unit 123 searches for a character string in the file in the storage to be searched based on the keyword input in step S1401. If there is a file in which a character string in the file includes a keyword, attribute information of the file is acquired as a display target. When the search of the file in the storage is completed, the process proceeds to step S1403. In the present embodiment, it is assumed that the search is performed by directly referring to the SPDF file, the WORD file, the Excel file or the like, but the present invention is not limited to this. For example, a database in which character strings in a file are indexed may be generated in advance, and the generated database may be referred to.

  In step S1403, the control unit 123 displays a screen showing a list of search results found in step S1402. FIG. 13B is an example of a screen showing a list of search results.

  In step S1404, the control unit 123 receives a user operation of selecting a document from the list of search results. In the document selection in this step, the user can also select a plurality of document files.

  In step S1405, the control unit 123 determines whether a user operation for printing the selected document has been accepted. If the determination result in this step is true, the process proceeds to step S1406, while if the determination result is false, the process proceeds to step S1407.

  In step S1406, the control unit 123 generates print data based on the selected document, and transmits the generated print data to the MFP (for example, the copying machine 110). The MFP that has received the print data forms an image on a recording medium such as a sheet based on the received print data.

  In step S1407, the control unit 123 determines whether a user operation for opening the selected document has been received. If the determination result in this step is true, the process proceeds to step S1408, while if the determination result is false, the process returns to step S1404.

  In step S1408, the control unit 123 opens the selected document with an application associated with the selected document extension.

  As described above, in the present embodiment, the full text search of the SPDF format document file stored in the information processing apparatus 120 can be performed. Thus, the user can easily find the material he needs. Also, the document file found by the search can be printed in cooperation with the copying machine 110. Therefore, a desired file can be easily searched and reprinted from various document files managed on the information processing apparatus. Therefore, the convenience of the user can be enhanced.

Other Embodiments
In the above-described embodiments, the information processing apparatus 120 and the copying machine 110 are connected by wire or wireless, but the present invention is not limited to this. For example, each function of the information processing apparatus 120 that generates an SPDF or manages each document file can also be realized as a server on the cloud. In this case, data read by a copying machine or the like is transmitted to a server on the cloud, converted to an SPDF file as necessary, and stored on the cloud storage. Also, the server on the cloud provides a web application accessible from the web browser or the like of the client PC. In this case, the user uses the full-text search function described in the sixth embodiment and the print function of the document file found in the search via the Web application.

  Moreover, in the above-mentioned embodiment, although PDF was illustrated as an example of a file which transforms into searchable, it is not limited to this. Other file formats (for example, XPS format proposed by Microsoft, XDW format file used in DocuWorks document proposed by Xerox) can be analyzed and converted into searchable files.

  The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

Claims (15)

First extracting means for extracting a character area in an image object included in the file;
Based on the positional relationship between the character area extracted by the first extraction means and the area where the character object included in the file is drawn, the file includes an image and a result of character recognition corresponding to the image. A first determination unit that determines whether or not the file is a searchable file that includes;
Generating means for executing a character recognition process on the image object in response to the first determination means determining that the file is not a searchable file, and generating a file including a result of the character recognition process; An information processing apparatus comprising: The information processing apparatus according to claim 1, wherein the first determination unit determines that the file is the searchable file when the following expression is satisfied.

In the above equation, X is the number of character areas in which the positional relationship between the character area in the image object and the area in which the character object is drawn satisfies a predetermined condition, and N is the first extraction. It is the total number of character areas extracted by the means, and S is a predetermined threshold.   The file from which the character area is extracted by the first extraction means is a PDF file, and the file generated by the generation means is a searchable PDF file to which the result of the character recognition processing is added as a transparent character object The information processing apparatus according to claim 1 or 2, wherein The apparatus further comprises a second determination unit that determines whether the PDF file includes an image equivalent to a page size before the determination by the first determination unit is performed,
When the second determination unit determines that the PDF file includes an image equivalent to a page size, the first determination unit determines whether the PDF file is the searchable PDF file. on the other hand,
When the second determination means determines that the PDF file does not contain an image of a page size, the first determination means determines whether the PDF file is the searchable PDF file. The information processing apparatus according to claim 3, wherein the information processing apparatus is not provided. When the second determination unit determines that the PDF file includes an image equivalent to a page size, the first extraction unit extracts a character region by dividing the image.
The character recognition process is performed on the character area extracted by the first extraction unit.
The generation unit generates a searchable PDF file to which a transparent character object indicating a character string obtained as a result of the character recognition process is added at the same position as the character area extracted by the first extraction unit. The information processing apparatus according to claim 4, wherein:   When the first determination unit determines that the PDF file input to the information processing apparatus is a searchable PDF file, the input does not generate a searchable PDF file based on the input PDF file. The information processing apparatus according to claim 3, wherein the stored PDF file is stored. A second extracting unit is further provided for extracting a plurality of files including saved searchable PDF files as a search target, and extracting a file in which a character string in the search target file includes a keyword designated by the user And
4. The information processing apparatus according to claim 3, wherein a list of files extracted by the second extraction unit is displayed on a display unit. The information processing apparatus is communicably connected to the image forming apparatus.
The print data generation method further includes generation means for generating print data based on the selected file in response to receiving a user operation for printing a file selected from the list, and the print data generated by the generation means The information processing apparatus according to claim 7, wherein the information processing apparatus transmits the image data to the image forming apparatus.   When the first determination means determines that the PDF file input to the information processing apparatus is a searchable PDF file, the user is asked whether the searchable PDF file is to be recreated based on the input PDF file. The information processing apparatus according to claim 3, wherein a prompt for causing selection is displayed on the display unit.   When recreating a searchable PDF file based on the PDF file input to the information processing apparatus, the information processing apparatus further includes a third determination unit that determines whether the transparent character string in the input PDF file is irrelevant to the content of the image. The information processing apparatus according to claim 9, characterized in that:   10. The information processing apparatus according to claim 9, wherein a prompt for causing the user to select whether to delete a transparent character string unrelated to the content of the image is displayed on the display unit.   10. The information processing apparatus according to claim 9, wherein only a character string having a high recognition rate is replaced with a transparent character string.   The first determination means determines the total number of character areas in the image object included in the file, and of the character areas, the character area whose position and size match the position and size of the transparent character object in the file. The information processing apparatus according to any one of claims 1 to 12, wherein whether or not the file is a searchable file is determined based on the number. An extraction step of extracting a character area in an image object included in the file;
The file includes an image and a result of character recognition corresponding to the image based on the positional relationship between the character area extracted in the extracting step and the area where the character object included in the file is drawn. A determination step of determining whether or not the file is a searchable file;
Generating a file including a result of the character recognition process by executing character recognition processing on the image object in response to the determination that the file is not a searchable file in the determination step; A method characterized by having.   A program for making a computer execute the method according to claim 14.

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