JP4412211B2 - Skew correction method, program, image processing apparatus, and image processing system - Google Patents

Description

  The present invention relates to a skew correction method, a program, an image processing apparatus, and an image processing system that perform skew correction on image data obtained by reading a document.

  There are many image document management systems that scan a document (original) with a scanner, save each page as an image, and manage it in document units. Image document management system scanners used in enterprise areas (large enterprises) are equipped with an automatic document feeder called ADF (Automatic Document Feeder), which automatically feeds documents with many pages and continuously In many cases, reading work is made more efficient.

  A paper document read from the ADF may be read and digitized while being inclined at the time of paper feeding. This tilting of image data is called “skew”, and the “skew correction function” that corrects skew and rotates the image in an upright direction is an essential function in an image document management system that handles scan data. is there.

Various techniques for performing skew correction have been put into practical use (see, for example, Patent Documents 1 to 7).
Japanese Patent Laid-Open No. 4-333983 Japanese Patent Laid-Open No. 4-153887 JP-A-4-287289 JP 2004-341865 A JP 2004-70720 A JP-A-5-274475 Japanese Patent Laid-Open No. 01-066782

  However, according to the conventional skew correction method, the correction accuracy varies depending on the content of the document, such as whether the document is mainly text or a photograph. On the other hand, it often happens that the algorithm inclines greatly. Many attempts have been made to improve the skew correction accuracy so that one skew correction algorithm can deal with documents of various contents, but image document management for the purpose of reading a large number of pages at once and managing them as documents. In a system, it is rare that complete skew correction can be performed.

  In such an image document management system, after a large number of pages are read and recorded as an image document, a skew is often found in a process of inspecting the read quality of the document (inspection process). The reading operation and the inspection operation are often performed by different people / locations. For this reason, when a skew is found during inspection, the operation of reading the corresponding page again becomes complicated, and the work efficiency is remarkably reduced.

  Accordingly, an object of the present invention is to correct the skew of an image read from a document and to improve the efficiency of inspection work, thereby improving the overall reading work efficiency, a program, and an image correction method. A processing apparatus and an image processing system are provided.

In order to achieve the above object, the present invention performs skew correction on a plurality of pages of image data using a plurality of skew correction algorithms for each page, and generates a plurality of corrected image data for one piece of the image data. 1 step, switching one corrected image data from the plurality of corrected image data to be displayed on the screen arranged for each page, and sequentially switching one corrected image data from the plurality of corrected image data for each page According to the second step of displaying the button on the screen and the image saving instruction, the corrected image data that is not displayed is deleted from the plurality of corrected image data for each page, and one is displayed for each page. include a third step of controlling so as to store the corrected image data to collectively storage unit as a file, the Providing skew correction method characterized.

  According to the skew correction method, a plurality of corrected image data is obtained for one image data, so that the corrected image data having the smallest inclination can be selected from the corrected image data.

  The “manuscript” includes various types such as text (mainly), mainly graphic, and mainly photo.

The first step may include a step of selecting a plurality of skew correction algorithms used for skew correction from a list of a plurality of skew correction algorithms.

In the second step, a plurality of corrected image data may be switched for each page and displayed on the screen, and one corrected image data may be selected by displaying one corrected image data on the screen by a switching operation. Since only one piece of corrected image data is displayed for each page, it is easy to compare the inclinations of the images by switching display.

In the second step, before displaying the corrected image data on the screen, a skew correction evaluation point is calculated for each of the plurality of corrected image data , and the corrected image data having the highest evaluation point is selected. It may be displayed first . It is possible to objectively compare the image inclinations based on the skew correction evaluation points.

  In order to achieve the above object, the present invention provides a program for causing a computer to execute the above skew correction method. Input of image data, skew correction, and selection of corrected image data are automated.

In order to achieve the above object, the present invention performs skew correction on a plurality of pages of image data using a plurality of skew correction algorithms for each page, and generates a plurality of corrected image data for one image data. And a switching button for sequentially displaying one corrected image data from the plurality of corrected image data for each page and displaying the corrected image data from the plurality of corrected image data for each page. According to the display control unit to be displayed on the screen and the image saving instruction, the correction image data not displayed among the plurality of correction image data for each page is deleted, and one correction image data is displayed for each page. image and a storage control unit which controls to collectively stored in the storage unit as a file, characterized in that with a To provide a management apparatus.

  According to the image processing apparatus, since a plurality of corrected image data is obtained for one image data from the correction unit, the selection unit can select correction image data having the smallest inclination among the correction image data. it can.

  The correction unit may include an algorithm selection unit that selects a plurality of skew correction algorithms used for skew correction from a list of a plurality of skew correction algorithms.

The display control unit includes a display unit that switches a plurality of corrected image data for each page and displays the corrected image data on the screen, and a switch button that switches the corrected image data displayed on the screen, and displays one corrected image data on the screen. In this case, one correction image data may be selected. Since only one piece of corrected image data is displayed for each page, it is easy to compare the inclinations of the images by switching display.

The display control unit calculates a skew correction evaluation point for each of a plurality of correction image data before displaying the correction image data on the screen, and selects the correction image data that has obtained the highest evaluation point first. It is good also as a structure to display . It is possible to objectively compare the image inclinations based on the skew correction evaluation points.

In order to achieve the above object, the present invention provides an image processing system including a scanner for inputting image data, a reading control device for controlling the scanner, and an editing device for editing the image data. A reading unit that reads image data from a document for each page, and the image data read by the reading unit is subjected to skew correction using a plurality of skew correction algorithms for each page. A correction unit that generates corrected image data, and the reading control device adds a page attribute to the plurality of corrected image data and transfers it to the editing device, and the editing device is transferred from the reading control device. side by side with and displays on the screen from the plurality of corrected image data of one correction image data for each page and, each page According to the display control unit for displaying on the screen a switching button for sequentially switching and displaying one corrected image data from the plurality of corrected image data, and among the plurality of corrected image data for each page according to an image saving instruction. An image processing system comprising: a storage control unit that deletes uncorrected correction image data and controls the storage unit to store correction image data displayed one for each page as a file. To do.

  According to the image processing system described above, since a plurality of corrected image data is generated for one image data on the scanner side, the correction image data having the smallest inclination is selected from the plurality of corrected image data on the editing device side. This can simplify the configuration of the reading control apparatus.

In order to achieve the above object, the present invention provides an image processing system having a scanner for inputting image data, a reading control device for controlling the scanner, and an editing device for editing the image data. A reading unit that reads image data for each page, and the reading control device performs skew correction on each of the image data read by the reading unit using a plurality of skew correction algorithms for each page. A correction unit that generates a plurality of corrected image data for the data, adds a page attribute to the plurality of corrected image data, and transfers the corrected attribute data to the editing device. The editing device is transferred from the reading control device. side by side with and displays on the screen from the plurality of corrected image data of one correction image data for each page and, each page According to the display control unit for displaying on the screen a switching button for sequentially switching and displaying one corrected image data from the plurality of corrected image data, and among the plurality of corrected image data for each page according to an image saving instruction. An image processing system comprising: a storage control unit that deletes uncorrected correction image data and controls the storage unit to store correction image data displayed one for each page as a file. To do.

  According to the image processing system described above, the correction control unit selects the correction image data having the smallest inclination from the plurality of correction image data on the editing device side in order to generate a plurality of correction image data for one image data on the reading control device side It is possible to simplify the configuration of the scanner.

  According to the present invention, it is possible to correct the inclination of an image read from a document, and to improve the efficiency of the inspection work, thereby improving the overall reading work efficiency.

[First Embodiment]
FIG. 1 shows an image document management system according to a first embodiment to which the image processing apparatus and system of the present invention are applied. The image document management system 1 includes a scanner 2 that reads document data (image data) from a document original, and a read operation host that is connected to the scanner 2 via a signal line 7 and that is used when reading document data. A personal computer (PC) 3, an inspection work host PC 4 as an editing device used when inspecting the reading quality of document data, and a printing device 5 for printing document data are provided. It is connected via the network 6.

  FIG. 2 shows the configuration of the scanner 2 and the reading work host PC 3 according to the first embodiment.

(Scanner configuration)
The scanner 2 includes an ADF (Automatic Document Feeder) 20 that automatically feeds document originals one by one to a reading position, an optical sensor 21 that reads document data page by page from a document original fed to the reading position, and an optical sensor. A buffer memory 22 for storing document data (RAW image data) read by the image data 21; and a skew correction processing ASIC (reading image data from the buffer memory 22 and performing a skew correction process using a plurality of skew correction algorithms for each page. Application Specific IC) 23, scanner data transfer control means 24 for transferring image data (corrected image data) skew-corrected by the skew correction processing ASIC 23 to the reading work host PC 2, and each part of the scanner 2 not shown. And a control unit.

(Configuration of the reading host PC)
The reading work host PC 3 controls the entire PC 3 and communicates with the scanner 2 and the inspection work host PC 4, etc., and a ROM, RAM, hard disk, etc. in which the CPU program and document data are stored. Storage unit, an input device such as a keyboard and a mouse, and a display such as a liquid crystal display and a CRT display.

  Examples of programs stored in the storage unit include a scanner driver 30 and image document management software 31. The scanner driver 30 includes a driver data transfer control unit 300 that performs data transfer control with the scanner 2 in accordance with a communication protocol, and an image file creation that creates a plurality of image data generated for each page as an image file for each page. Part 301. The image document management software 31 manages documents according to the document format.

(Configuration of inspection work host PC)
The inspection work host PC 4 controls the entire PC 4, and communicates with the reading work host PC 3 and the printing device 5, etc., and is transferred from a CPU program such as a display control program and an editing program, and the scanner 2. A storage unit such as a ROM, RAM, and hard disk for storing the document data and the like, an input device such as a keyboard and a mouse, and a display such as a liquid crystal display and a CRT display.

(Configuration of printing device)
The printing apparatus 5 can use various methods such as an electrophotographic method, an ink jet method, and a thermal transfer method. The printing apparatus 5 may be connected to a post-processing apparatus such as printed paper sorting and bookbinding.

(Operation of the first embodiment)
Next, the operation of the first embodiment will be described with reference to the flowchart of FIG.

(1) Reading Work The reading worker sets a plurality of document originals on the ADF 20 of the scanner 2 (S1), operates the input device of the reading work host PC 3 to display the skew correction mode selection screen on the display, and performs skew. A correction mode is selected (S2).

  FIG. 3 shows the skew correction mode selection screen. The skew correction mode selection screen 50 includes a check box 51 for enabling skew correction, and check boxes 52, 53, and 54 for selecting a text mode, a graphic mode, and a photo mode when skew correction is enabled. Is provided. When the text mode, the graphic mode, or the photo mode is selected, a skew correction algorithm suitable for an original mainly composed of text, an original composed mainly of graphics, and an original composed mainly of photographs is executed. In the case of the figure, the case where the skew correction valid is selected and the text mode and the graphic mode are selected is shown.

  When the reading operator depresses a start key (not shown) after selecting the skew correction mode, the ADF 20 automatically feeds document originals one by one to the reading position under the control of the control unit of the scanner 2, and the optical sensor 21 The document data is read page by page from the document document fed to the reading position (S3). The document data (RAW image data) read by the optical sensor 21 is temporarily stored in the buffer memory 22 (S4).

  Next, the skew correction processing ASIC 23 reads the RAW image data from the buffer memory 22 and performs the skew correction processing using the plurality of skew correction algorithms selected in step S2. The scanner data transfer control means 24 controls the skew correction processing ASIC 23 to receive the image data after the skew correction processing in a plurality of times from the skew correction processing ASIC 23 and transfer it to the reading work host PC 3.

  The driver data transfer control unit 300 of the reading work host PC 3 passes the image data transferred from the scanner 2 to the image file creation unit 301. The image file creation unit 301 creates a plurality of image data generated for each page as an image file for each page according to the document format.

  FIG. 4 shows the document format. The document is composed of a plurality of pages 1, page 2,..., And each page is composed of a plurality of images 1, images 2,... Corresponding to a plurality of skew correction algorithms. In addition, a document can be set with a priority skew correction mode and a skew correction change page list as document attributes, and a preview display image and a skew correction mode can be set as page attributes for each page. It can be done.

  The “priority skew correction mode” is a skew correction mode that is preferentially displayed as a preview display of all pages among a plurality of skew correction modes selected on the skew correction mode selection screen 50, and is set in advance. “Preview display” refers to display of an image on a document data inspection screen described later. The “skew correction change page list” refers to a list of pages in which the skew correction mode set in the priority skew correction mode is changed.

  By setting the skew correction mode in advance in the priority skew correction mode, the preview display image of each page is determined in a lump, and thereafter, the preview display image can be changed for each page. In the case of FIG. 4, the graphic mode is set in the priority skew correction mode and the preview display of each page is changed to the image 2, and then the preview display of the page 2 is changed to the image 1.

  Next, the reading operator determines whether reading is necessary due to forgetting reading, occurrence of jam, etc. If reading is necessary (S5), the page image is replaced (S6), and reading is not necessary in the above step S5. In this case, or after replacing the page image, each page image is registered as a document (S7).

  When the reading work is finished, the reading worker operates the input device of the reading work host PC 3 to instruct the transmission of the document data. Then, the CPU of the reading work host PC 3 sends the document data to the inspection work via the network 6. To the host PC 4 (S8). Document data is stored in the storage unit of the PC 4.

(2) Inspection work When the inspection worker operates the input device of the inspection work host PC 4 to instruct the start of inspection work, the CPU displays a document data inspection screen on the display (S9).

  FIG. 5 shows the document data inspection screen. On the document data inspection screen 60, images 61a, 61b, 61c are displayed for each page, and below the images 61a, 61b, 61c of each page, image switching buttons 62a, 62b for switching the image to be displayed. Is provided. Initially, an image corresponding to the skew correction mode set in the priority skew correction mode is displayed. When it is determined that the image quality is poor because the displayed image has a large tilt (S10), the displayed image is switched by operating the image switching buttons 62a and 62b (S11). When the cursor is moved to the image switching button 62a and clicked, the display image returns, and when the cursor is moved to the image switching button 62b and clicked, the display image advances. The CPU of the inspection work host PC 4 changes the preview image of the page attribute shown in FIG. 4 in accordance with the operation of the image switching buttons 62a and 62b in accordance with the editing program. The image change is reflected in the page attribute as shown in FIG.

  When the inspection work is finished and an instruction to save the image is given, the document data composed of the image of each page displayed as a preview on the document data inspection screen 60 is collected as a file, and the file is saved in the storage unit. At this time, the second and subsequent images on each page of the document data inspection screen 60 are automatically deleted as unselected images. Thereby, the size of the file can be reduced.

(3) Printing of document data Next, when the inspection operator operates the input device of the inspection work host PC 4 to specify a file, set printing conditions and instruct printing, the CPU of the inspection work host PC 4 The printing conditions and file are transferred to the printing apparatus 5. The printing device 5 prints the document data in the file on paper according to the printing conditions.

(Effects of the first embodiment)
According to the first embodiment, when each page of a document is preview-displayed at the time of inspection, an image processed with another correction algorithm on the spot for a page whose skew is determined not to be correct. Since the frequency of performing the reading operation again becomes low, the user can have a user interface that is not conscious of the presence of a plurality of images, and an efficient inspection work can be performed.

[Second Embodiment]
FIG. 7 shows a configuration of a main part of an image document management system according to the second embodiment of the present invention. The image document management system according to the second embodiment is the same as that of the first embodiment except that the transfer buffer memory 25 is added to the scanner 2 in the first embodiment. Yes. According to the second embodiment, an efficient inspection work can be performed as in the first embodiment, and since the transfer buffer memory 25 is provided in the scanner 2, skew correction and transfer operations are performed. Can be done asynchronously.

[Third Embodiment]
FIG. 8 shows the configuration of the main part of an image document management system according to the third embodiment of the present invention. In the third embodiment, the RAW image data read by the scanner 2 in the first embodiment is directly transferred to the reading work host PC 3 and skew correction is performed by the PC 3. The configuration is the same as that of the first embodiment.

  The scanner 2 includes an ADF 20, an optical sensor 21, a scanner data transfer control unit 24, and a control unit (not shown) that controls each unit of the scanner 2, and includes a buffer memory 22 and a skew correction processing ASIC 23 as in the first embodiment. Not.

  The reading work host PC 3 includes skew correction processing software 302 that performs skew correction processing on the RAW image data transferred from the scanner 2 by using a plurality of skew correction algorithms for each page. Note that the skew correction processing software 302 may be realized using a skew correction processing ASIC.

  According to the third embodiment, an efficient inspection work can be performed as in the first embodiment, and the skew correction processing software 302 is provided on the PC 3 side, so that a general-purpose scanner is used. be able to.

[Fourth Embodiment]
FIG. 9 shows a schematic configuration of an image document management system according to the fourth embodiment of the present invention. In the fourth embodiment, in the third embodiment, a skew correction evaluation point calculation unit 303 is added to the reading work host PC3, and the inspection display host PC4 controls image display based on the skew correction evaluation points. The others are configured in the same manner as in the third embodiment.

  In the fourth embodiment configured as described above, when the RAW page data is transferred from the scanner 2 to the reading work host PC 3, the RAW page data is stored in the skew correction processing software 302 of the reading work host PC 3. Thus, skew correction is performed using a plurality of skew correction algorithms, and a plurality of image data is obtained. The skew correction evaluation point calculation unit 303 calculates skew correction evaluation points for each of a plurality of image data, and transfers the image data together with the evaluation points to the inspection work host PC4. The CPU of the inspection work host PC 4 first displays the image data having the highest evaluation score on the document data inspection screen similar to FIG.

  In the case of FIG. 9, since the complementary accuracy (evaluation point) in the skew correction mode 1 is 95% and the complementary accuracy in the skew correction mode 2 is 70%, the image 1 with the higher evaluation point is displayed as a preview.

  According to the fourth embodiment, an efficient inspection work can be performed as in the third embodiment, and the comparison of the inclination of the image based on the skew correction evaluation point can be objectively performed. It can be carried out.

[Other embodiments]
Note that the present invention is not limited to the above embodiments and examples, and various modifications can be made without departing from the scope of the invention. For example, the constituent elements of each embodiment can be arbitrarily combined without departing from the scope of the invention.

  Alternatively, an optical reading operation may be performed for each page by a scanner a plurality of times, and an image subjected to skew correction processing may be transferred to the host computer by applying each algorithm each time.

  Also, one or more skew correction algorithms used for each page or page range may be set. Thereby, useless skew correction can be reduced.

  Alternatively, skew correction may be performed on one RAW image data using a plurality of algorithms, and a plurality of obtained images may be displayed side by side. As a result, since the images can be compared without switching the images, it is possible to quickly select an image with a small inclination and to increase the efficiency of the inspection work.

  In the above embodiment, the image document management system is configured by the scanner, the reading PC, the inspection PC, and the printing apparatus. However, the reading PC and the inspection PC may be configured by one PC.

It is a block diagram which shows the image document management system which concerns on the 1st Embodiment of this invention. 1 is a diagram illustrating a configuration of a scanner and a reading work host PC according to a first embodiment. FIG. It is a figure which shows the skew correction mode selection screen which concerns on 1st Embodiment. It is a figure which shows the document format which concerns on 1st Embodiment. It is a figure which shows the document data inspection screen which concerns on 1st Embodiment. It is a flowchart which shows operation | movement of the image document management system which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the principal part of the image document management system which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the principal part of the image document management system which concerns on the 3rd Embodiment of this invention. It is a figure which shows schematic structure of the image document management system which concerns on the 4th Embodiment of this invention.

Explanation of symbols

1 Image document management system 2 Scanner 3 Host PC for reading work
4 Host PC for inspection work
5 Printer 6 Network 7 Signal Line 21 Optical Sensor 22 Buffer Memory 24 Scanner Data Transfer Control Unit 25 Transfer Buffer Memory 23 Skew Correction Processing ASIC
30 Scanner driver 31 Image document management software 50 Skew correction mode selection screen 51, 52, 53, 54 Check box 60 Document data inspection screen 61a, 61b, 61c Image 62a, 62b Image switching button 300 Driver data transfer control means 301 Image file creation Unit 302 skew correction processing software 303 skew correction evaluation point calculation unit

Claims (8)

A first step of performing skew correction on a plurality of pages of image data using a plurality of skew correction algorithms for each page and generating a plurality of corrected image data for the one image data;
One correction image data from the plurality of correction image data is arranged on a page and displayed on the screen, and a switching button for sequentially switching and displaying one correction image data from the plurality of correction image data for each page is displayed on the screen. A second step to display ;
According to the image save instruction, the corrected image data that is not displayed is deleted from the plurality of corrected image data for each page, and the corrected image data that is displayed for each page is collectively stored in the storage unit as a file. A third step of controlling
Including a skew correction method. In the second step, before displaying the corrected image data on the screen, a skew correction evaluation point is calculated for each of the plurality of corrected image data, and the corrected image data having the highest evaluation point is selected. The skew correction method according to claim 1, wherein the skew correction method is displayed first . Program for executing the skew correction method according to the computer to claim 1 or 2. A correction unit that performs skew correction using a plurality of skew correction algorithms for each page of image data of a plurality of pages, and generates a plurality of corrected image data for the one image data;
One correction image data from the plurality of correction image data is arranged on a page and displayed on the screen, and a switching button for sequentially switching and displaying one correction image data from the plurality of correction image data for each page is displayed on the screen. A display control unit to display;
According to the image save instruction, the corrected image data that is not displayed is deleted from the plurality of corrected image data for each page, and the corrected image data that is displayed for each page is collectively stored in the storage unit as a file. A storage control unit for controlling
An image processing apparatus comprising: The display control unit calculates a skew correction evaluation point for each of the plurality of correction image data before displaying the correction image data on the screen, and selects the correction image data that has obtained the highest evaluation point. The image processing apparatus according to claim 4 , wherein the image processing apparatus is displayed first . The correction unit is used for the skew correction from a list including a skew correction algorithm suitable for a text-based document, a skew correction algorithm suitable for a graphic-based document, and a skew correction algorithm suitable for a photograph-based document. The image processing apparatus according to claim 4, further comprising an algorithm selection unit that selects the plurality of skew correction algorithms. In an image processing system having a scanner for inputting image data, a reading control device for controlling the scanner, and an editing device for editing the image data,
The scanner performs a skew correction using a plurality of skew correction algorithms for each page of the image data read by the reading unit and the image data read by the reading unit for each page. A correction unit that generates a plurality of corrected image data,
The reading control device adds a page attribute to the plurality of corrected image data and transfers it to the editing device,
The editing device displays one corrected image data from the plurality of corrected image data transferred from the reading control device for each page, and displays the corrected image data from the plurality of corrected image data for each page. In accordance with a display control unit that displays on the screen a switching button for sequentially switching and displaying data, and in accordance with an image save instruction, corrected image data that is not displayed is deleted from a plurality of corrected image data for each page, and for each page An image processing system comprising: a storage control unit that controls to store the corrected image data displayed one by one in a storage unit as a file . In an image processing system having a scanner for inputting image data, a reading control device for controlling the scanner, and an editing device for editing the image data,
The scanner includes a reading unit that reads image data from a document for each page,
The reading control device performs skew correction on each of the image data read by the reading unit by using a plurality of skew correction algorithms for each page, and generates a plurality of corrected image data for one piece of the image data. A page attribute is added to the plurality of corrected image data and transferred to the editing device,
The editing apparatus arranges one corrected image data from the plurality of corrected image data transferred from the reading control apparatus for each page and displays the corrected image data on the screen, and one corrected image from the plurality of corrected image data for each page. In accordance with a display control unit that displays on the screen a switching button for sequentially switching and displaying data, and in accordance with an image save instruction, corrected image data that is not displayed is deleted from a plurality of corrected image data for each page, and for each page An image processing system comprising: a storage control unit that controls to store the corrected image data displayed one by one in a storage unit as a file .