Abstract:
Methods for storing and managing hard copy documents and their modified versions are disclosed. Specifically, a method of storing a document and one or more related images of alterations made to the document, comprising capturing an image of the document; storing the image of the document in memory; capturing an image of an altered version of the document; comparing the image of the document to the image of the altered version of the document; extracting the differences between the image of the document and the image of the altered version of the document; creating an image of the extracted differences between the image of the document and the image of the altered version of the document; and storing the image of the extracted differences in memory.

Description:
RELATED APPLICATIONS 
       [0001]    Benefit is claimed under 35 U.S.C. 119(a)-(d) to Foreign application Serial No. 1321/CHE/2009 entitled “Document Storage System” by Hewlett-Packard Development Company, L.P., filed on 5 Jun. 2009, which is herein incorporated in its entirety by reference for all purposes. 
       BACKGROUND 
       [0002]    Many organizations, particularly in emerging markets, primarily use printed hard copy documents in their processes. Also in many cases these organizations receive hard copy documents such as invoices from other organizations that may need to be processed by the organization. However, using hard copy documents to conduct business may cause difficulties in an organization. 
         [0003]    For example, physical storage and movement of hard copy documents can be costly. It also may be difficult to determine the status or location of such hard copy documents, resulting in inefficiencies in workflow. Authentication of hard copy documents also can be time-consuming. Finally, because hard copy documents generally require sequential processing, it may be difficult for multiple users to work on a hard copy document simultaneously, and may be difficult to incorporate changes from multiple users. 
         [0004]    Despite all these difficulties, businesses continue to use hard copy documents. Many businesses simply are not willing to or cannot transition to an entirely paperless business processes using computers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1A  is a block diagram of a document storage system showing the status of a hard copy document as it moves through the system, according to an embodiment of the disclosure. 
           [0006]      FIG. 1B  is a block diagram of the document storage system of  FIG. 1A  showing the status of an altered version of the hard copy document as it moves through the system, according to an embodiment of the disclosure. 
           [0007]      FIG. 2  is a flow chart showing the steps in a process of storing documents according to an embodiment of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    The present illustrative methods and systems may be adapted to store printed documents. Specifically, the present illustrative systems and methods may, among other things, be adapted to store an image of a printed document and related images of subsequent changes made to the printed document. Changes may be stored as overlays, each overlay including the differences between one version of the document and the next version of the document. Images thus can be reassembled to produce any version of a document in the workflow, even without physical access to the original document or current document. Further details of the present illustrative document storage systems and methods are provided below. 
         [0009]      FIG. 1A  shows a document storage system  10 . The document storage system  10  may include one or more of an image capture device  20 , an image processor  30 , an input processor  40 , memory  50 , a comparison processor  60 , an output processor  70 , and a hard copy document processor  80 . Also shown in  FIG. 1A  is an example original hard copy document  12  that has not previously been entered into the system. Original hard copy document  12  may be any physical record and may include text, data, figures, graphs, pictures, notations, or any other information capable of documentation. In the present example, original hard copy document  12  is shown having content represented by a triangle in an upper region of a page of media. 
         [0010]    As indicated, system  10  may be used to associate an identifier with an original hard copy document  12 , and to produce an identified hard copy document  14  that includes such identifier. This is shown generally in  FIG. 1A , where processing of hard copy document  12  is tracked through the system by showing an image of the original document as it progresses through components that may be integrated into system  10 . 
         [0011]    When original hard copy document  12  enters system  10 , the document is sent to image capture device  20  which may be capable of capturing an image of the hard copy document. For example, image capture device  20  may be a scanner, all-in-one printer, multi-function printer, or digital camera. Image capture device  20  also may be configured to capture metadata from original hard copy document  12 . Metadata may be captured from the content of the hard copy document, such as texture, feature points, or hash generated from the content. Alternatively, metadata may be supplied by a user of system  10  by swiping an identity card, entering information using alphanumeric keys provided on system  10 , or using an application ported into system  10 . 
         [0012]    Once an image has been captured (shown at  22 ), the captured image may be transmitted to image processor  30 . Image processor  30  may be configured to recognize an identifier, if present, on captured image  22 . As will be appreciated, a hard copy document need not have an identifier the first time it is entered into system. For purposes of illustration, hard copy document  12  is shown without an identifier. Accordingly, in the example shown in  FIG. 1A , captured image  22  does not include an identifier. 
         [0013]    If image processor  30  does not recognize an identifier, image processor  30  may direct the reviewed image (shown at  32 ) to input processor  40 , which may be configured to generate an identifier. The identifier may be any suitable indicator capable of distinguishing the present image from another image. For example, the identifier may be a unique barcode that may be printed directly on the hard copy document, or on a label that may be affixed to the hard copy document. Alternatively, or additionally, the identifier also may be data supplied by a user of the system, or may be defined by metadata extracted from or related to the hard copy document. For example, the identifier may be defined by feature points found on the hard copy document, or any other metadata gathered by image capture device  20 . 
         [0014]    Input processor  40  also may assign or identify certain additional information related to the image. For example, input processor  40  may assign a version number, indicate the employee that modified the version, indicate the time the document was last altered or entered into system  10 , and other related information. This additional information may be found in metadata of the hard copy document. In some embodiments, the additional information may be encoded in the manner similar to that used to encode the identifier, such as in a barcode. Similar to the identifier, the additional information may be parsed by system  10 . It should be appreciated that the additional information may be updated each time the hard copy document is entered into system  40 . 
         [0015]    In the example of  FIG. 1A , the identifier is represented by a line adjacent the lower edge of the hard copy document. After input processor  40  generates and assigns the hard copy document an identifier, an identified image  42  may be stored in memory  50 . The identifier may be stored with identified image  42  for future reference or retrieval. A copy of the identified image (shown at  44 ) may be transmitted to output processor  70 . In some embodiments, output processor  70  may include a printer capable of printing the identifier on the original hard copy document to produce identified original document  14 . Alternatively, a label may be printed for placement on original hard copy document  12  to produce the identified document, or a copy of the original document may be generated with the identifier thereon to produce the identified original document. Thereafter, identified original document  14  may return to regular workflow. 
         [0016]    System  10  also may include a document processor  80  operably connected to input processor  40 , memory  50  and output processor  70 . Document processor  80  may be configured to retrieve selected identified images from memory  50  and send the identified images to output processor  70  or permit a user to view and/or alter an electronic version of selected images. The selected identified images may be printed and sent into regular workflow. 
         [0017]      FIG. 1B  shows the document storage system of  FIG. 1A  processing a modified hard copy document  16 , which is a physically altered version of document  14  from  FIG. 1A . In this example, it will be understood that identified image  42  (having content in the form of a triangle in an upper region of the page) has been saved in memory  50  with an identifier that will be decoded when modified hard copy document  16  (having an added circle in a central region of the page) is entered into system  10 . As will be described in detail below, when the previously-identified image (shown at  46 ) is compared to a corresponding image of modified hard copy document  16 , a difference image (including the extracted differences between the original and modified documents, both identified) may be produced (having only the added circle in the central region of the page) and saved in memory  50 . 
         [0018]    As described above, when modified document  16  is entered into system  10 , image capture device  20  may capture an image of the hard copy document. The resulting captured image (shown at  24 ) may then be transmitted to image processor  30 , which may be configured to review the captured image to determine whether the captured image includes an identifier for use in identifying the captured image. 
         [0019]    Upon noting an identifier associated with captured image  24 , image processor  30  may direct the reviewed image (shown at  34 ) to input processor  40 . As noted above, reviewed image  34  may include additional information such as the document version, the last person to alter the document, and the last time the document was entered into system  10 . The additional information may be updated by input processor  40  when the hard copy document is entered into system  10 . For example, a new document version may be assigned, and a new editor and/or time stamp may be entered. 
         [0020]    Using the identifier, input processor  40  then may retrieve previously-identified image  46  using the identifier derived from reviewed image  34 . Input processor  40  then may transmit the previously-identified image  46  and a copy of the reviewed image (shown at  48 ) to comparison processor  60 . Comparison processor  60  may compare images  46  and  48 , extract the differences between the images, and produce a difference image  62  containing the extracted differences. Comparison processor  60  may then store the difference image  62  in memory  50 . 
         [0021]    Difference image  62  may be related in memory  50  to previously-identified image  46  for future retrieval therewith. The identifier may be the same so as to associate difference image  62  and previously-identified image  46  in memory  50 . Difference image  62  also may include updated additional information. For example, difference image may include the new version number, time entered, and person or employee that made the alterations. Upon retrieval in a future operation, the difference image may be re-integrated with the previously-identified image to establish a previously-identified modified image for comparison to a further-modified image so as to extract the differences between modified and further-modified documents. It thus will be appreciated that the hard copy document may be stored in memory as an identified image and one or more related difference images representing successive modifications to the hard copy document. Accordingly, with each successive processing of the hard copy document, a difference image of the most recent modifications to the hard copy document (those made since the previous processing of the document) are captured and stored. 
         [0022]    Additionally, system  10  may permit a user to access and alter a copy of image saved in memory  50 . The user may access the copied image from memory  50  through document processor  80 . After the copied image is retrieved by document processor  80 , the user may electronically alter the copied image. For example, the user may review the copied image for approval or insert electronic comments. After electronic alterations have been made, the copied image may be sent from document processor  80  to input processor  40 . Thereafter, the process described above with reference to  FIG. 1B  is followed to extract the electronic differences present in the copied image. Specifically, the copied image is sent to input processor  40  in the same state as reviewed image  34  and is processed in the same manner. 
         [0023]      FIG. 2  is a flow chart showing an illustrative example of a process  100  by which a document may be stored according to the present disclosure. Process  100  may be initiated upon capturing an image of a hard copy document as indicated at  110 . The captured image thereafter may be reviewed to determine whether the captured image contains an identifier (as indicated at  120 ). 
         [0024]    If no identifier is noted, an identifier is generated and assigned to the document (as indicated at  130 ). An identified image is then stored in memory, typically, along with the identifier (as indicated at  132 ). The identifier will accommodate future retrieval of the identified image from memory upon receipt of the document in a subsequent processing operation. Once generated, the identifier may be placed on the hard copy document (as indicated at  134 ). After the identifier has been placed on the hard copy document, and the image of the document has been stored in memory with the identifier, the hard copy document may return to regular workflow (as indicated at  160 ). 
         [0025]    Once back in regular workflow, alterations, such as notes, marks, or other appropriate annotations may be made on the hard copy document. For example, if the hard copy document is a test that a student has taken, the test grader may place notes, comments, and/or grades on the hard copy document. If the hard copy document is participating in a hard copy workflow those participating in the workflow may annotate the document as it moves from one state to another. If the hard copy document is a medical case sheet the document would contain symptoms and diagnosis as record by a doctor during different visits to the hospital. 
         [0026]    Subsequently, the modified document may be reintroduced to the document storage system, and an image of the modified document may be captured (as indicated at  110 ). Upon determining that there is an identifier associated with the hard copy document, the identifier may be decoded (as indicated at  140 ). Once the identifier has been decoded, the corresponding previously-identified image is retrieved from memory (as indicated at  142 ). The previously-identified image may then be synchronized with the captured image for subsequent comparison of the images (as indicated at  144 ). Differences between the captured image and the corresponding previously-identified image are extracted (as indicated at  148 ) and the extracted differences are stored in memory (as indicated at  150 ). 
         [0027]    For example, if an “X” were placed in the lower left corner of the hard copy document, then the “X” in the lower left hand corner would be extracted. However, the two images must be synchronized to ensure only the differences between the documents are extracted. The process of synchronizing, or image registration, may include aligning and scaling the images to one another. Image registration may be performed by any of the well known methods including a) area-based methods such as the Fourier method, or b) feature-based methods such as SIFT and RANSAC. After completing image registration, any annotations may be extracted by calculating the binary difference between the images. 
         [0028]    To extract the differences between the images the captured image and the previously-identified image (retrieved from memory) are binarized. Next, the difference between the binarized images may be calculated. For example, the calculation may be made in a 3×3 pixel neighborhood to determine if there is a difference between pixels in the images. This calculation may be completed for each pixel to extract any differences between the images. 
         [0029]    Once all the differences have been extracted, an image of the extracted differences may be created. The newly created image may be stored in memory. Additionally, the image of the extracted differences may be related in memory to the image retrieved from memory for comparison. This way the original image of the document is saved and the image of the alterations to the document are saved together for future reference and comparison. Upon completion, the hard copy document that was entered into process may return to regular workflow where additional alterations may be made. 
         [0030]    While particular forms of the invention have been illustrated and described herein, it will be apparent that various modifications and improvements can be made to the invention. Moreover, individual features of embodiments of the invention may be shown in some drawings and not in others, but those skilled in the art will recognize that individual features of one embodiment of the invention can be combined with any or all the features of another embodiment. Accordingly, it is not intended that the invention be limited to the specific embodiments illustrated. It is intended that this invention to be defined by the scope of the appended claims as broadly as the prior art will permit.