WO2010061456A1 - Information processing device, information processing method and image processing program - Google Patents

Abstract

It is an object to encrypt or decode a part of electronic information with simple work. In order to achieve the object, an information processing device is provided with a transmissive display element display means (21) that makes a display device display a transmissive window displayed on a display (105), an information acquisition means (22) that acquires display information covered with the transmissive window out of the display information displayed on the display (105) as a digital image, an encryption means (11) that encrypts the acquired digital image, and an encrypted image output means (12) that outputs the encrypted image so that an image encrypted by the encryption means (11) is displayed in place of the display information covered with the transmissive window.

Description

Information processing apparatus, image processing method, and image processing program

The present invention relates to a technique for encrypting and decrypting an electronic document.

As a technology dealing with encryption of printed matter, the entire image is first divided into a plurality of blocks, the images of the divided blocks are rearranged based on the parameters obtained from the input password (encryption key), and the image of the block specified by the parameters There is a technique for encrypting an image by reversing black and white and mirror reversal (see Patent Document 1). When decrypting an encrypted image, a positioning frame is added to the outside of the image, a password (decryption key) is input, and then the original image is decrypted in the reverse procedure of encryption.

In addition, there is a technique in which black and white squares of a predetermined size representing binary data are arranged in a matrix and embedded in a printed material (see Patent Document 2). Further, a positioning symbol is added to the printed matter at a predetermined position in the matrix so that the imaged position can be known at the time of decoding. Using this positioning symbol as a reference, an image is taken with a scanner or camera, and the embedded information is decoded.
Japanese Patent Application Laid-Open No. 8-17989 Japanese Patent No. 2938338

The computerized information is easy to duplicate and spreads rapidly over a network such as the Internet. Therefore, there is a problem that the influence when important information is leaked is enormous. For this reason, in order to prevent leakage of information, conventionally, computerized information is encrypted.

However, since the digitized information is usually encrypted by being subjected to encryption processing such as conversion as binary data, the encrypted data cannot be opened unless it is decrypted (such as on a display). There was a problem that it cannot be viewed. In particular, in the conventional method, even if the information to be concealed is a part of the digitized information, the entire digitized information is encrypted. Was difficult.

Also, when encrypting part of the digitized information, dedicated software for encrypting part of the digitized information is required. For this reason, when it is desired to encrypt only a part of a conventionally used document creation application, spreadsheet application, etc., other applications such as a document creation application, a spreadsheet application, etc. It is necessary to provide compatibility for handling file formats such as.

In view of the above problems, an object of the present invention is to encrypt or decrypt a part of electronic information with a simple operation.

In order to solve the above-described problems, the present invention acquires a digital image of an area covered by a transparent display area, encrypts the digital image, and displays the encrypted image instead of the original display information. With this output, part of the electronic information can be encrypted with a simple operation.

Specifically, the present invention relates to an information processing apparatus connected to a display device, the display element being displayed in a part of a display area of the display device, wherein at least a part of the display element is transmissively displayed. The transparent display element display means for causing the display device to display the transparent display element that allows the display information covered by the display element to be visually recognized, and among the display information displayed in the display area, Information acquisition means for acquiring display information covered by a transparent display element as a digital image, encryption means for encrypting the digital image acquired by the information acquisition means based on an encryption key, and the transparent display An information processing apparatus comprising: encrypted image output means for outputting the encrypted image so that the encrypted image encrypted by the encryption means is displayed instead of the display information covered by the element. That.

The present invention is also an information processing apparatus connected to a display device, wherein the display element is displayed in a part of a display area of the display device, and at least a part of the display element is transparently displayed. Thus, the transparent display element display means for displaying on the display device a transparent display element that allows the display information covered by the display element to be visually recognized, and the transparent display among the display information displayed in the display area. Information acquisition means for acquiring display information covered by an element as an encrypted image, decryption means for decoding the encrypted image acquired by the information acquisition means based on a decryption key, and the transparent display element An information processing apparatus comprising: decoded information output means for outputting the decoded information so that the decoded information decoded by the decoding means is displayed instead of the covered display information.

The information processing apparatus according to the present invention is a computer connectable to a display device. Here, the display device may be any device that displays information in response to a signal output from the information processing device. The display device includes a display device that displays a two-dimensional image, such as a liquid crystal display or a CRT (Cathode Ray Tube) display, which is conventionally used as a monitor for a computer. A display device capable of performing typical display may be used. In addition to the display area provided in the display device main body, a configuration other than the display device main body may be used as the display area. For example, a projector or the like that projects an image other than the display device main body corresponds to this.

In the present invention, the display information displayed by the display device includes general information that can be displayed by the information processing device, such as characters and graphics. Further, when displaying these pieces of information on a display device connected to the information processing device, the display information may be associated with display position information for specifying a display position in the display area. The display position information is, for example, information indicating the coordinates at which a window is displayed in an information processing apparatus equipped with a multi-window system, the size of the window, etc., each display element (character, graphic, etc.) displayed in the desktop or window Information indicating the coordinates, size, and information indicating the coordinates of the pixels. However, the display position information may be specified by information other than the coordinates and size, for example, a vector or a pixel number.

In the present invention, among various display elements displayed by the display device, the display information covered by the display element (in other words, the display information superimposed on the back of the display element) is transmitted and visible. A display element is used. As display elements displayed by the display device, there are those called a desktop gadget, a widget, etc. in addition to a window in a computer equipped with a multi-window system, and generally, an input device such as a mouse or a keyboard is used. It is a display element that can be rearranged in accordance with an input user instruction.

That is, the information processing apparatus according to the present invention further includes an input receiving unit that receives an input that indicates the display position of the transparent display element, and the transparent display element display unit is based on the instruction received by the input receiving unit. The transparent display element may be displayed at the display position.

In a display device that displays a two-dimensional image, such as a liquid crystal display or a CRT display, which is conventionally used as a monitor for a computer, the transmissive display element actually transmits color information of a portion where the transmissive display element is displayed. By combining with the color information of the image of the part covered by the display element (the part corresponding to the back of the transparent display element) and adjusting it, it is displayed as if the image on the back is transparent from the user, and the display element The covered part is made visible. However, as a specific method for displaying the transmissive display element, a method for performing three-dimensional display, a translucent display film, and the like as well as a method for adjusting color information that is generally used at present. Various methods such as a method of making the back surface visible by displaying on the screen may be adopted.

Further, the transparent display element according to the present invention is for providing an image encryption function or a decryption function as the above-exemplified window or desktop gadget. The present invention acquires display information covered by such a transparent display element, that is, information that can be seen through the transparent display element when viewed from the user, and uses the acquired digital image as an image. It is characterized in that it is encrypted or decrypted and displayed in place of the original display information.

The transparent display element display means causes the display device to display the transparent display element in association with display position information for specifying a display position in the display area, and the information acquisition means includes the transparent display element. The display information covered by the element may be acquired based on the display position information of the information and the display position information of the transparent display element. More specifically, the information acquisition means associates a display position specified using display position information associated with the display information, among the display information displayed in the display area, with the transparent display element. The display information covered by the transmissive display element may be acquired by extracting display information that overlaps the display position specified using the displayed display position information.

By having such characteristics, it is possible to create transparent display elements such as a conventional document creation application and a spreadsheet application without individually creating an application having a function of encrypting or decrypting a part of an electronic document or the like. It is possible to easily add an encryption function or a decryption function that is not originally provided in an application relating to a window or the like displayed in the back by using the function of the transparent display element without the need for modification or change of the application. Further, conventionally, the technology for displaying such a transparent element has been used only for the purpose of increasing the amount of information visible to the user or for the purpose of enhancing the aesthetics, whereas at least one of the display elements is used. By utilizing the characteristic that the part is transparent, it is possible to arrange the transparent display element on the confidential information by user operation, acquire the information, and encrypt or decrypt the image.

Here, an electronic document refers to a document including some information such as an electronic document, a chart, an illustration. The present invention replaces a portion covered with a transparent window in an electronic document with an encrypted encrypted image or decrypted decrypted information, so that an encryption target portion is visually encrypted. An electronic document or a decrypted electronic document can be generated.

The encrypted image output means may output the display information covered by the transparent display element to replace the display information, or the decrypted information output means may You may output so that this display information may be substituted with respect to the file containing the display information covered by the said transparent display element. That is, when the display information covered by the transparent display element is information displayed by, for example, a document creation application, the display information is cut out for the document creation application, and an encrypted image or decrypted information is used instead. To display a part of the information displayed by the document creation application in an encrypted or decrypted state, and furthermore, an electronic document related to the information displayed by the document creation application Can be replaced with encrypted or decrypted information.

Furthermore, the present invention can also be grasped as a method executed by a computer or a program for causing a computer to function as each of the above means. Further, the present invention may be a program in which such a program is recorded on a recording medium readable by a computer, other devices, machines, or the like. Here, a computer-readable recording medium is a recording medium that stores information such as data and programs by electrical, magnetic, optical, mechanical, or chemical action and can be read from a computer or the like. Say.

According to the present invention, a part of electronic information can be encrypted or decrypted with a simple operation.

It is a figure which shows the outline of the hardware constitutions of the information processing apparatus which concerns on embodiment. It is a figure which shows the outline of a function structure of the information processing apparatus which concerns on embodiment. It is a flowchart which shows the flow of the encryption process by the encryption application based on Embodiment. It is a figure which shows the state which the transparent window which concerns on embodiment was superimposed on the window of the spreadsheet application, and was moved to the position which covers the display information used as the object of encryption. In an embodiment, it is a figure showing an image of an electronic document containing an encryption picture outputted by an encryption picture output part, and a transparent window used for encryption. It is a figure which shows the state which the transparent window based on embodiment was superimposed on the window of the document preparation application, and was moved to the position which covers the display information used as the object of encryption. FIG. 7 is a diagram illustrating a state in which an encryption process using a transparent window is performed from the state illustrated in FIG. 6 and an electronic document including an encrypted image is displayed in a window of a document creation application. It is a figure which shows the outline of a function structure of the information processing apparatus which concerns on embodiment. It is a flowchart which shows the flow of the decoding process by the decoding application based on embodiment. It is a figure which shows the process outline | summary (the 1) of an encryption process and a decoding process. It is a figure which shows the process outline | summary (the 2) of an encryption process and a decoding process. It is a figure which shows the outline | summary of the encryption process in a 1st aspect. It is a figure which shows the example which selects an encryption area | region. It is a figure which shows the example of input of an encryption key. It is a figure which shows an example of the scramble process in an image conversion part. It is a figure which shows the other example of the scramble process in an image conversion part. It is a figure which shows the modification of the shape of the micro area | region in a scramble process. It is a figure which shows the compression process in an image conversion part. It is a figure which shows the process which images conversion data. It is a figure which shows the example (the 1) of the pixel value conversion process in a pixel value conversion part. It is a figure which shows the example (the 2) of the pixel value conversion process in a pixel value conversion part. It is a figure which shows the example of the positioning marker used by an encryption process. It is a figure which shows the example of an encryption image. This is an example in which a grayscale image is encrypted. It is a figure which shows the outline | summary of the decoding process in a 1st aspect. It is a figure which shows the process of detecting an encryption area | region from a positioning marker. It is a flowchart which shows the flow of an encryption area | region detection process. It is a figure which shows the example by which the encryption position was detected. It is a figure which shows the whole image of a 2nd aspect. It is a figure which shows the outline | summary of the encryption process in a 2nd aspect. It is a figure which shows the outline | summary of the decoding process in a 2nd aspect. It is a figure for demonstrating the detection method of an encryption area | region. It is a figure for demonstrating the detection method of an encryption position (horizontal direction). It is a figure which shows the example which detected the detection of the encryption position incorrectly. It is a figure which shows the outline | summary of the encryption process in a 3rd aspect. It is a figure which shows the outline | summary of the decoding process in a 3rd aspect.

Embodiments of the present invention will be described with reference to the drawings.

<Encryption of electronic documents>
First, an encryption application for performing partial encryption of an electronic document using a transparent window according to the present invention will be described. FIG. 1 is a diagram illustrating an outline of a hardware configuration of an information processing apparatus 200 according to the present embodiment. The information processing apparatus 200 includes a CPU (Central Processing Unit) 101, a main storage device such as a RAM (Random Access Memory) 102, an auxiliary storage device such as an HDD (Hard Disk Drive) 103, and a ROM (Read Only Memory) 104, etc. And is connected to a display 105 as a display device, a mouse 106 and a keyboard 107 as input devices, and the like.

FIG. 2 is a diagram illustrating an outline of a functional configuration of the information processing apparatus 200 according to the present embodiment. The computer according to the present embodiment is covered by the transparent display element display unit 21 that displays the transparent window on the display 105 by the CPU interpreting and executing the encrypted application program expanded in the RAM 102 or the ROM 104, and the transparent window. The information acquisition unit 22 that acquires the display information, the input reception unit 23 that receives various inputs from the user such as an input that indicates the display position of the transparent window, and the information acquired by the information acquisition unit 22 based on the encryption key It functions as an information processing apparatus 200 that includes an encryption unit 11 that converts an encrypted image and an encrypted image output unit 12 that outputs the converted encrypted image.

In this embodiment, each of these functional units is realized by the CPU executing each software module included in the encrypted application program. However, each of these functional units is implemented by a dedicated processor or the like. It may be realized. The computer according to the present embodiment is managed by an OS (Operating System) having a multi-window system, and the encryption application program is installed in the HDD of this computer.

The transparent display element display unit 21 displays a transparent window on the display 105 in response to the activation of the encryption application program. Here, the transparent window according to the present embodiment functions as a transparent display element according to the present invention by transparently displaying part or all of the window as a display element. However, the transparent display element according to the present invention only needs to be displayed as a user interface for providing a certain function, and other than what is usually called a window, what is called a so-called desktop gadget or widget. There may be. Note that the transparent window may be displayed by using an API (Application Program Interface) of the OS or an API of a program execution environment (for example, Adobe Air (registered trademark)) installed in the OS.

The transparent window is attached with information (referred to as a “window identifier” in the present embodiment) for identifying the window, as with other windows displayed using the functions of the OS and the program execution environment. The display position information of the window is stored in the RAM 102 or the HDD 103 in association with the window identifier. That is, in the present embodiment, the display position of the transparent window is managed by the OS and the program execution environment.

The information acquisition unit 22 acquires information on a portion covered by the transparent portion of the transparent window, that is, a portion seen through the transparent window from the display information displayed on the display 105. Here, the information acquisition part 22 acquires the information of the part covered with the transparent window as a digital image which is a set of pixels. The window position information described above is used when such information is acquired. A more specific method for acquiring information will be described later.

FIG. 3 is a flowchart showing a flow of encryption processing by the encryption application according to the present embodiment. The process shown in this flowchart starts when the user clicks on the icon of the encrypted application using a transparent window, and the OS of the information processing apparatus 200 is instructed to start the application. Is done. Further, the processing order described below is an example, and the specific processing order may be appropriately changed according to the embodiment.

In step S101, a transparent window is displayed. The transmissive display element display unit 21 displays a transmissive window so as to occupy a part of the display area of the display 105. Here, the display 105 in the present embodiment is a display device that displays in a display area where a two-dimensional image can be displayed. For this reason, the transmissive display element display unit 21 acquires color information of a portion where the transmissive portions of the transmissive window overlap, and adjusts the color information so that a part of the window is seen from the user's perspective, An image is displayed on the display 105 so that the covered information can be seen through. The display position of the transparent window displayed here is managed by associating the window identifier and display position information indicating the display position in the display area. The display position information of the transparent window is recorded in the RAM 102 or the HDD 103 in association with the window identifier. Thereafter, the process proceeds to step S102.

In step S102, the display position of the transparent window is updated. The input receiving unit 23 updates the display position of the transparent window according to an instruction to update the display position of the transparent window by a user operation using an input device such as the mouse 106 and the keyboard 107. For example, the input receiving unit 23 issues an instruction to update the display position (including the shape and size of the transparent window) based on a so-called drag-and-drop operation using the mouse 106 or an operation using the direction key. The transparent window is received and moved to the designated position, and the transparent window is enlarged or reduced to the designated size. However, the specific display position instruction operation may be performed by another input method using another input device, and the display position instruction may not be based on a user operation. For example, a function for designating a predetermined area or a function for designating an area in which a preset keyword is displayed, and an instruction to update the display position so that a transparent window is displayed to cover these areas. May be issued. Thereafter, the process proceeds to step S103.

FIG. 4 is a diagram showing a state in which the transparent window 303 according to the present embodiment is moved to a position where the transparent window 303 is superimposed on the spreadsheet application window 300 and covers display information to be encrypted. On the display 105, a window 300 of an electronic document handled by a spreadsheet application is displayed, and a transparent window 303 is displayed superimposed on the window 300. Here, the transparent window 303 is displayed in a position and size covering the area (here, a so-called cell) 302 containing information that the user wants to encrypt in the window 300.

In step S103, an encryption start instruction is accepted. The input receiving unit 23 receives an input of an encryption start instruction by a user operation using an input device such as the mouse 106 and the keyboard 107. That is, after starting the encryption application, the user displays the transparent window on the display, then moves the transparent window to the position where the information to be encrypted is displayed, and instructs the information processing apparatus to start encryption. To start encryption using a transparent window. At this time, as a user operation for instructing to start encryption, an operation of clicking a predetermined position using the mouse 106, a gesture operation using the mouse 106, a command operation using the keyboard 107, and the like are employed. It's okay. Thereafter, the process proceeds to step S104.

In step S104, information on the portion covered by the transparent window is acquired. Specifically, the information acquisition unit 22 is covered with the transparent window by extracting display information included in the display position of the transparent window displayed in step S101 from the display information displayed on the display 105. Get part information. Here, the display information is acquired as an image as a set of pixels. The information acquisition unit 22 cuts out a portion corresponding to the area indicated by the display position information (coordinates, size, etc.) of the transparent window from the image information drawn for the output of the display 105, so that the digital to be encrypted is obtained. Get an image. When the information of the part covered by the transparent window is acquired by the information acquisition unit 22, the process proceeds to step S105.

In step S105, encryption is performed. The encryption unit 11 generates an encrypted image according to the digital image and the encryption key acquired in step S104. Also, as the encryption key used at this time, a preset key may be used, or an encryption key input interface is displayed and input by the user each time encryption processing is performed. Also good. Details of the encryption processing will be described later. Thereafter, the process proceeds to step S106.

In step S106, an encrypted image is output. The encrypted image output unit 12 deletes the code corresponding to the part to be encrypted from the displayed electronic document, and instead of the deleted code, the encrypted image data itself or the encrypted image An encrypted electronic document is generated by inserting a link to. More specifically, the encrypted image output unit 12 covers the application related to the window (window 300 in the example of FIG. 3) on which the display information to be encrypted is displayed with a transparent window. The selected part (cell 302 in the example of FIG. 3) is selected and deleted, and a series of operations for inserting the encrypted image generated at the deletion position (cell 302) is performed. That is, according to the present embodiment, the encrypted image output unit 12 reproduces the user operation for replacing the display information with the encrypted image with respect to the display information to be encrypted, For any application, part of the information can be encrypted. However, the encrypted image may be delivered internally instead of reproducing the user operation. Thereafter, the processing shown in this flowchart ends.

FIG. 5 is a diagram showing an image of the electronic document including the encrypted image output by the encrypted image output unit 12 and the transparent window 303 used for encryption in the present embodiment. FIG. 5 shows a state in which the encryption process by the transparent window 303 is performed from the state shown in FIG. 4 and an electronic document including the encrypted image 302B is displayed in the window 300 of the spreadsheet application. The encrypted image output unit 12 deletes the code corresponding to the text portion 302 from the original electronic document, and inserts the encrypted image 302B in place of the deleted code, thereby encrypting the spreadsheet application. Generate an electronic document.

FIG. 6 is a diagram showing a state in which the transparent window 303 according to the present embodiment is moved to a position where the transparent window 303 is superimposed on the document creation application window 300B and covers the display information to be encrypted. FIG. 7 is a diagram illustrating a state in which the encryption process using the transparent window 303 is performed from the state illustrated in FIG. 6 and the electronic document including the encrypted image 301B is displayed in the window 300B of the document creation application. . The electronic document includes a character string 301 and a graphic 304. Here, a part of the character string 301 and the graphic 304 are covered with a transparent window 303 as display information to be encrypted. Then, the encrypted image 301B generated by the encryption application is inserted into the electronic document instead of a part of the character string 301 and the graphic 304.

According to FIG. 6 and FIG. 7, the partial encryption of the electronic document using the transparent window according to the present embodiment is not limited to the electronic document handled by the spreadsheet application exemplified by using FIG. 4 and FIG. It can be seen that the present invention can be applied to a wide range of electronic documents such as an electronic document handled by a document creation application. That is, the partial encryption using the transparent window according to the present embodiment has an interface capable of editing the displayed electronic document by basic user operations such as selection, deletion, and insertion. It can be applied to any application as long as it is an application.

<Decryption of electronic document>
Next, a decryption application for performing partial decryption of an electronic document using a transparent window according to the present invention will be described. FIG. 8 is a diagram illustrating an outline of a functional configuration of the information processing apparatus 500 according to the present embodiment. The computer according to the present embodiment is covered with a transparent display element display unit 21 that displays a transparent window on the display 105 by the CPU interpreting and executing the decryption application program expanded in the RAM 102 or the ROM 104, and the transparent window. An information acquisition unit 22 that acquires display information, an input reception unit 23 that receives various inputs from the user, such as an input that indicates the display position of a transparent window, and decrypts information (encrypted image) acquired by the information acquisition unit 22 It functions as an information processing apparatus 500 including a decryption unit 14 that converts to decrypted information based on a key, and a decrypted information output unit 501 that outputs decrypted information. Note that the hardware configuration of the information processing apparatus 500 is substantially the same as that of the information processing apparatus 200, and thus the description thereof is omitted (see FIG. 1).

The information acquisition unit 22 acquires an encrypted image included in the electronic document encrypted by the information processing apparatus 200. The acquired encrypted image may be selected by a user operation, or may be automatically selected by detecting a regular pattern included in the encrypted image. The encrypted image according to the present embodiment has a regular pattern generated by converting the pixel value of the input image, as will be described later.

The decrypted information output unit 501 generates a decrypted electronic document. In the decrypted electronic document, the digital image decrypted by the decryption unit 14 is output instead of the encrypted image in the portion where the encrypted image is output when the encrypted electronic document is output without being decrypted. Electronic document. The decrypted information output unit 501 deletes the code (image data itself or link information) corresponding to the encrypted image from the encrypted electronic document, and describes a link to the decrypted digital image instead of the deleted code. By doing so, a decrypted electronic document is generated. However, the image data itself may be replaced from the encrypted image to the decrypted image without changing the code.

In addition, the decoded information output unit 501 detects characters in the digital image decoded by the decoding unit 14 using a so-called OCR (Optical Character Recognition) technique, thereby identifying the characters in the digital image as characters. An electronic document including character information by code may be generated. By restoring the character code, format information, and the like from the decrypted digital image, an electronic document that is the same as or close to the electronic document used for encryption can be obtained. The generated electronic document is preferably an electronic document in a format that can be handled by the same application as the application that generated the electronic document before encryption. In addition to the characters, the electronic document generation unit 501 detects and specifies the format, charts and illustrations included in the digital image, and the arrangement thereof, so that the electronic document is close to the electronic document before being encrypted. Can be generated more accurately. By restoring the electronic document close to the electronic document before being encrypted, the decrypted information can be handled as the electronic document, and the convenience for the user is improved.

FIG. 9 is a flowchart showing a flow of decryption processing by the decryption application according to the present embodiment. The processing shown in this flowchart is started when the user clicks on the decryption application icon using the transparent window and the OS of the information processing apparatus 200 is instructed to start the application. The Further, the processing order described below is an example, and the specific processing order may be appropriately changed according to the embodiment.

In step S201, a transparent window is displayed. The transmissive display element display unit 21 displays a transmissive window so as to occupy a part of the display area of the display 105. The details of the transparent window display process are the same as in step S101 described in the encryption process, and a description thereof will be omitted. Thereafter, the process proceeds to step S202.

In step S202, the display position of the transparent window is updated. The input receiving unit 23 updates the display position of the transparent window according to an instruction to update the display position of the transparent window by a user operation using an input device such as the mouse 106 and the keyboard 107. The user uses an input device such as the mouse 106 and the keyboard 107 to display the transparent window at a position covering the encryption area. FIG. 5 and FIG. 7 described above are diagrams showing an image at the time when the encryption process is completed. However, a state in which a transparent window is arranged at a position covering the encrypted image to be decrypted in the decryption process is also shown. The same. The details of the process are the same as step S102 described in the encryption process, and thus the description thereof is omitted. Further, the indication of the display position may not be based on the user operation. For example, the position where the encrypted image is displayed is automatically detected based on the function for designating a predetermined area, the positioning marker described later, the regularity of the encrypted image, and the like. An instruction to update the display position may be issued so that the transparent window is displayed so as to cover these areas by the function of designating the areas where the converted image is displayed. Thereafter, the process proceeds to step S203.

In step S203, a decryption start instruction is accepted. The input receiving unit 23 receives an input of a decoding start instruction by a user operation using an input device such as the mouse 106 and the keyboard 107. That is, after starting the decryption application, the user displays a transparent window on the display, then moves the transparent window to the position where the encrypted image to be decrypted is displayed, and instructs the information processing apparatus to start decryption. By giving, decoding using a transparent window is started. At this time, as a user operation for a decoding start instruction, an operation of clicking a predetermined position using the mouse 106, a gesture operation using the mouse 106, a command operation using the keyboard 107, and the like are employed. Good. Thereafter, the process proceeds to step S204.

In step S204, an encrypted image is acquired. The information acquisition unit 22 acquires information on a portion covered by the transparent window by extracting display information included in the display position of the transparent window displayed in step S101 from the display information displayed on the display 105. To do. The details of the image acquisition process are the same as in step S104 described in the encryption process, and a description thereof will be omitted. Thereafter, the process proceeds to step S205.

In step S205, decryption is performed. The decryption unit 14 decrypts the encrypted image to generate a digital image that has been decrypted. As the decryption key used at this time, a preset key may be used, or a decryption key input interface may be displayed and input by the user each time decryption processing is performed. . Details of the decoding process will be described later. Thereafter, the process proceeds to step S206.

In step S206, the decrypted information is output. The decrypted information output unit 501 deletes the encrypted image (or link information to the encrypted image) from the electronic document including the encrypted image covered by the transparent window, and replaces the deleted code with the decrypted information. A decrypted electronic document is generated by inserting the information. The details of the specific processing for replacing the encrypted image using the decrypted information are substantially the same as the processing in step S106 shown in the flowchart of FIG. 3 except that the replacement target is different. Omitted. Thereafter, the processing shown in this flowchart ends.

According to this embodiment, only a user who knows a decryption key by distributing an electronic document including important information for which viewing restrictions are set and information for which browsing restrictions are not set without removing the important information from the electronic document. It is possible to browse information described in the encrypted part. In addition, by performing image processing with overlapping transparent windows and replacing the information of the position where the transparent windows are overlapped with the image processing results, a part of the electronic document can be encrypted or encrypted regardless of the data format of the electronic document. Decoding is possible.

In this embodiment, partial encryption and partial decryption of an electronic document are realized by using different transparent windows for the encryption application and the decryption application. However, the encryption is performed in a single transparent window. It is also possible to have both functions of decoding and decoding.

<Encryption unit and decryption unit>
Next, an outline of encryption processing and decryption processing by the encryption unit and the decryption unit in the embodiment will be described.

FIG. 10 is a diagram showing a processing outline (part 1) of the encryption process and the decryption process. In FIG. 10, an encryption unit 11 (in the first to third aspects, referred to as encryption units 11A, 11B, and 11C, respectively) is based on an input digital image and an encryption key indicating an encryption method. Thus, an encrypted image obtained by encrypting a part of the digital image is output. The printer output unit 12 prints the digital image encrypted by the encryption unit 11 on a printable physical medium such as paper. The scanner (camera) reading unit 13 reads the print image output from the printer output unit 12 using a scanner or a camera.

Then, the decryption unit 14 (in the first to third aspects, referred to as decryption units 14A, 14B, and 14C, respectively) decrypts the print image output by the printer output unit 12 and the input decryption key. Get. Only when the input decryption key is correct, the encrypted image can be properly decrypted, and the information hidden by the encryption by the encryption unit 11 can be viewed.

FIG. 11 is a diagram showing a process outline (part 2) of the encryption process and the decryption process. As shown in FIG. 11, the encryption process and the decryption process in the first to third aspects to which the present invention is applied perform the digital image encrypted by the encryption unit 11 without using a printer or a scanner. It is also possible to input the electronic document image as it is to the decoding unit 14 to obtain a decoded image.

Next, the first to third aspects to which the present invention is applied will be described. First, the 1st aspect to which this invention is applied is demonstrated.

FIG. 12 is a diagram showing an outline of the encryption processing in the first mode. In FIG. 12, the encryption unit 11 </ b> A includes an encryption area determination unit 31, an image conversion unit 32, a pixel value conversion unit 33, and a marker addition unit 34.

The encryption area designating unit 31 selects an area to be encrypted from the input image including the area to be encrypted.

FIG. 13 is a diagram showing an example of selecting an encryption area. That is, as shown in FIG. 13A, the encryption area designating unit 31 selects the area 42 to be encrypted from the digital image (input image) 41 including the area to be encrypted. This area 42 is converted into a converted image 43 as shown in FIG. 13B by the processing of the image conversion unit 32 and the pixel value conversion unit 33 described later, and the digital image 41 is an encrypted image including the converted image 43. 44.

Returning to the explanation of FIG. When the area 42 to be encrypted is selected by the encryption area designating unit 31, the area 42 to be encrypted and the encryption key are input in the image conversion unit 32, and the image of the area 42 to be encrypted by the conversion method corresponding to the encryption key Is visually transformed. The conversion parameter at that time is created from binary data obtained from the input encryption key.

FIG. 14 is a diagram showing an input example of the encryption key. The example shown in FIG. 14 is an example of an encryption key and binary data generated by the encryption key. For example, a numerical value “1234” as an encryption key is input as binary data “100011010010”, and a character string “ango” as an encryption key is input as binary data “01100001011011100110011101101111”.

As the image conversion method, in the first aspect, there are two methods: a conversion method by dividing the image into minute regions and rearranging the minute regions (referred to as scramble processing) and a conversion method by compressing the image. Show.

First, the scramble process will be described. In the scramble process, first, the image of the selected area 42 is divided into small areas of a certain size, and then the small areas are rearranged by binary data obtained from the encryption key.

FIG. 15 is a diagram illustrating an example of the scramble process in the image conversion unit. As shown in FIG. 15A, first, the area 42 selected by the encryption area designating unit 31 is divided in the vertical direction, and each bit of the binary string of the encryption key 61 is used as the boundary of the divided area 42. Corresponding in order from the left, when the bit is “1”, adjacent divided columns are exchanged, and when the bit is “0”, nothing is performed in order from the left. When the number of bits in the binary string is insufficient with respect to the number of division boundaries, the same binary string is repeated from the position where the binary string is insufficient, and the exchange processing is performed up to the right end of the region 42.

Subsequently, as shown in FIG. 15B, the image area 62 that has undergone the above-described exchange processing is divided in the horizontal direction, and each bit of the binary string of the encryption key 61 is moved up to the boundary of the divided image area 62. The same exchange processing as that performed in the vertical division is performed in order from the top in line units.

Then, as shown in FIG. 15C, as a result of performing the exchange process on each divided image, a scrambled image 63 that is a processed image obtained by scrambled the original area 42 is obtained.

As an expansion method of this scramble processing example, the horizontal direction and the vertical direction can be performed twice or more, and the size of the divided area can be changed in the second and subsequent replacements. Furthermore, another binary string can be used for exchanging the divided areas in the horizontal direction and the vertical direction. These extension methods are particularly effective as means for preventing the same processed image from being generated from different encryption keys when the size of the input image is small and the bit length of the encryption key is long.

FIG. 16 is a diagram illustrating another example of the scramble process in the image conversion unit. As another scramble processing method different from the scramble processing described with reference to FIG. 15, a method of exchanging pixels in units of minute regions as shown in FIG. 16 is also possible. That is, the input image is divided into rectangular minute areas, and the divided minute areas are exchanged. As a result, the number of scrambles is increased and the encryption strength can be increased as compared with the above-described method using the exchange between the horizontal direction and the vertical direction (row and column).

FIG. 17 is a diagram showing a modification of the shape of the micro area in the scramble processing. Further, as the shape of the micro area in the scramble processing, for example, a triangle as shown in FIG. 17A can be used in addition to the quadrangle shown in FIG. Further, as shown in FIG. 17B, minute regions having different shapes and sizes can coexist.

Next, a conversion method by compressing an image will be described.

FIG. 18 is a diagram showing compression processing in the image conversion unit. When the input image 41 is a binary image, the image of the area 42 selected by the encryption area designating unit 31 is first compressed as shown in FIG. 18A, and shown in FIG. A binary string 71 is created. The compression methods here include all kinds of compression, such as run-length compression used when transferring binary image data in a facsimile machine and JBIG (Joint Bi-level Image experts Group) compression, which is a standard compression method for binary images. The method is applicable.

FIG. 19 is a diagram showing a process for converting the converted data into an image. Subsequent to the compression of the area 42 as shown in FIG. 18, each bit of the binary string 71, which is the converted compressed data, is “white” if the bit is “0”, as shown in FIG. If the bit is “1”, the rectangular image (processed image) 81 is created by enlarging the rectangle to a specified size of “black”, and arranged as a monochrome rectangular image 81 in the area 42 of the image to be encrypted.

When it is desired to arrange the converted compressed data (binary string 71) so as to fit within the image of the selected region 42, the size of the rectangular image 81 depends on the compression rate of the selected region 42. For example, if the compression ratio is 1/4 or less, the size of the square image 81 is 2 × 2 pixels at most, and if it is 1/16 or less, the size is 4 × 4 pixels.

On the other hand, when the size of the square image 81 is designated in advance and it is desired to store the compressed data in the image of the selected area 42, it is necessary to achieve a compression ratio depending on the size of the square image 81 in the first image compression processing. There is. For example, when the square is 4 × 4 pixels in size, a compression ratio of 1/16 or more is required. In this case, a method in which information in the selected area 42 is dropped in advance and a method using an irreversible compression method are effective.

The encryption process for enlarging and compressing the compressed data described above can recognize the enlarged black and white block even when the encrypted image is read with a low resolution camera, for example, so that the encrypted image can be correctly decrypted.

Returning to the explanation of FIG. The pixel value conversion unit 33 converts the pixels in the processed image 63 converted by the image conversion unit 32 at regular intervals so that the converted image 43 forms a substantially grid-like striped pattern.

FIG. 20 is a diagram illustrating an example (part 1) of the pixel value conversion process in the pixel value conversion unit. In the pixel value conversion unit 33, the pixels of the processed image 63 in which the area 42 is scrambled by the image conversion unit 32 are converted at regular intervals so that the encrypted image 44 forms a generally grid-like striped pattern as a whole. . For example, as shown in FIG. 20, the conversion is performed such that the scrambled image 63 shown in FIG. 20A is inverted at the colored portion of the checkered pattern (checkered) image 91 shown in FIG. As a result, as shown in (C), the converted image 92 in which the encrypted image 44 as a whole forms a substantially grid-like striped pattern is obtained. Thereby, the generated striped pattern is used to detect the detailed position of each pixel in the encryption area when the encrypted image 44 is decrypted.

It is possible to carry out another conversion for these series of processes. For example, the process of inverting the pixel value may be a process of adding a specified value.

Also, the checkered pattern image 91 shown in FIG. 20B is substantially the same size as the scrambled image 63 shown in FIG. 20A, but by using a size smaller than the scrambled image 63, the periphery of the scrambled image 63 is displayed. Only the center part other than the above may be reversed.

FIG. 21 is a diagram illustrating an example (part 2) of the pixel value conversion process in the pixel value conversion unit. Further, various shapes can be applied to the region 42 where the pixel value is converted, as shown in FIGS. Since the pixel value conversion is a process aimed at detecting the boundary position between the small areas with high accuracy, it is also conceivable to convert the pixel value only at the boundary part as shown in FIG. Further, by performing pixel value conversion while shifting little by little with respect to the minute area as shown in FIG. 21B, the boundary between conversion and non-conversion appears at finer intervals. The pixel position can be detected in more detail. In addition, if pixel value conversion is performed only on a portion where the boundaries of minute regions intersect as shown in FIG. 21C, image quality degradation when reading and decoding an image printed on paper or the like with a scanner or camera is minimized. Can be suppressed.

Here, the shape of the minute region is not a square having a uniform size, but a triangle (FIG. 17A) or different sizes and shapes coexist as shown in FIG. 17 (FIG. 17B). ) Is not limited to the above-described conversion example, it is added that it is necessary to perform pixel value conversion by a method according to the shape.

As described above, in the present invention, the regular pattern representing the encrypted position is not generated by overwriting the input image as in Patent Document 1, but is generated by converting the pixel value of the input image. is doing. Therefore, unlike the prior art, the image information at the end of the encrypted image is not sacrificed for position detection, and the original image information can be efficiently encrypted in the form of coexisting position detection information. The

Note that if some image information is included in the portion constituting the pattern, the regularity is somewhat lost. However, as described in the process of the decryption unit 14 described later, the statistical properties of the entire encrypted image are used to encrypt the image. The position can be detected.

Returning to the explanation of FIG. The marker adding unit 34 adds the positioning markers to, for example, three places other than the lower right among the four corners of the converted image 92 converted by the pixel value converting unit 33 to create the encrypted image 44.

The marker adding unit 34 arranges positioning markers for specifying the position of the encrypted area 42 at, for example, three positions other than the lower right among the four corners of the converted image 92.

FIG. 22 is a diagram showing an example of a positioning marker used in the encryption process. The positioning marker used in the first mode is assumed to have a round cross shape as shown in FIG. If the shape of the positioning marker is more broadly described, it may be constituted by a solid circle or polygon and a plurality of lines intersecting with the circumference. As an example of this, three lines from the center toward the circumference, such as those in the shape of a Chinese character “field” like the positioning marker in FIG. Examples include those that appear in a radial pattern, and those in which the line is cut halfway like the positioning marker of (D).

In addition, the color configuration of the positioning marker may be the simplest as long as the background is white and the foreground is black, but is not limited thereto, and may be appropriately changed according to the color (pixel value) distribution of the converted image 92. Absent. In addition, instead of designating a predetermined color for the background and the foreground, a method of forming a positioning marker by inverting the foreground pixel values while the background color remains the digital image 41 may be considered. In this way, it is possible to encrypt the image while retaining the input image information of the positioning marker portion.

FIG. 23 is a diagram showing an example of an encrypted image. The encrypted image 44 as shown in FIG. 23 is finally generated by the processing of the encryption unit 11A. The encrypted image 44 includes a converted image 92 and a positioning marker 121.

Furthermore, in the encryption method according to the first aspect, when “processing for rearranging minute regions (scramble processing)” is used in the image conversion unit 32, not only binary images but also grayscale or color images are used. Even encryption processing can be applied.

FIG. 24 shows an example in which a grayscale image is encrypted. In FIG. 24, the grayscale image 131 shown in (A) generates an encrypted image 132 including a converted image 133 and a positioning marker 134 as shown in (B) by the processing of the encryption unit 11A.

Next, the decoding unit 14A will be described.

FIG. 25 is a diagram showing an outline of the decryption process in the first mode. In FIG. 25, the decryption unit 14A includes a marker detection unit 141, an encryption area detection unit 142, an encryption position detection unit 143, and an image reverse conversion unit 144.

The marker detection unit 141 detects the position of the positioning marker added by the marker adding unit 34 from the encrypted image using a general image recognition technique. As a detection method, pattern matching, analysis on graphic connectivity, or the like can be applied.

The encryption area detection unit 142 detects an encrypted image area based on the positional relationship between the three positioning markers detected by the marker detection unit 141.

FIG. 26 is a diagram showing a process of detecting the encryption area from the positioning marker. As shown in (A) of FIG. 26, when at least three positioning markers 152 are detected from the encrypted image 151 by the marker detection unit 141, as shown in (B), one encrypted area 153 is stored. Can be detected. That is, since the three positioning markers 152 are arranged at the four corners of the rectangular encryption area 153, the figure obtained by connecting these three points (positions of the positioning markers 152) with lines is approximately a right triangle. Therefore, when three or more positioning markers 152 are detected, the positional relationship of the three positioning markers 152 includes an area configured in a shape close to a right triangle, and the positions of the three positioning markers 152 are set to four corner portions. A rectangle having three corners is defined as an encryption area 153. If the number of detected positioning markers 152 is two or less, the corresponding encrypted area 153 cannot be specified, and therefore the decryption process is terminated because there is no encrypted image.

FIG. 27 is a flowchart showing the flow of the encryption area detection process. In the encryption area detection process executed by the encryption area detection unit 142, first, in step S1601, the number of positioning markers 152 detected by the marker detection unit 141 is substituted into a variable n, and in step S1602, the encryption area detection process is performed. 0 is substituted into the detection flag reg_detect 153.

In step S1603, it is determined whether or not the variable n to which the number of positioning markers 152 is assigned is 3 or more. If the variable n is not 3 or more, that is, if the variable n is 2 or less (step S1603). : No), the decryption process including the present encrypted area detection process is terminated.

On the other hand, if the variable n is 3 or more (step S1603: Yes), in step S1604, three positioning markers 152 among the positioning markers 152 detected by the marker detection unit 141 are selected, and the selection is performed in step S1605. It is determined whether or not the positional relationship between the three positioning markers 152 is a substantially right triangle.

If the positional relationship between the three selected positioning markers 152 is not a substantially right triangle (step S1605: No), whether or not all three combinations of the positioning markers 152 detected by the marker detection unit 141 have been completed in step S1606. If not completed (step S1606: No), the process returns to step S1604 to select the other three points, and if completed (step S1606: Yes), the process proceeds to step S1608.

On the other hand, if the positional relationship between the selected three positioning markers 152 is a substantially right triangle (step S1605: Yes), 1 is substituted into the detection flag reg_detect in step S1607.

In step S1608, it is determined whether 1 is assigned to the detection flag reg_detect, that is, whether or not the three positioning markers 152 whose three-point positional relationship is a right triangle can be detected, and the reg_detect is set. If 1 is assigned (step S1608: Yes), the process proceeds to the process of the encrypted position detection unit 143. If 1 is not assigned to reg_detect (step S1608: No), decryption including the encryption area detection process is performed. The process ends.

Returning to the explanation of FIG. The encrypted position detecting unit 143 uses the fact that the end portion of the encrypted area 153 detected by the encrypted area detecting unit 142 forms a regular pixel distribution in order to correctly decrypt the encrypted image 151. Then, the detailed position of each pixel in the encryption area 153 is detected by frequency analysis or pattern matching. This detection uses the property that the entire encrypted image 151 forms a periodic pattern by the pixel value conversion (inversion) processing of the pixel value conversion unit 33.

As one detection method, the pattern period (width) is first obtained by a frequency analysis method such as Fast Fourier Transform (FFT) in the horizontal and vertical directions of the image, and then the boundary position (offset) by template matching or the like. ) Can be considered.

Also, it is possible to detect the boundary position by Hough transform by utilizing the property that the boundary part becomes linear when an edge detection filter (Laplacian filter or the like) is applied to the encrypted image.

FIG. 28 is a diagram showing an example in which the encrypted position is detected. When the encrypted digital image 41 is complicated, there is a possibility that a portion where the periodicity of the encrypted image 44 is significantly impaired appears. In such a case, it is effective to perform the encryption position detection by limiting the image area used for the calculation of the pattern period and the boundary position to a portion having a relatively strong periodicity.

Returning to the explanation of FIG. The image reverse conversion unit 144 uses the encrypted position information detected by the encrypted position detection unit 143 and the decryption key input by the user to convert the encrypted image 44 into the image conversion unit 32 by a method corresponding to the decryption key. The inverse conversion process of the conversion process by is executed to generate a decoded image. The decryption processing procedure is realized by the reverse procedure of the encryption processing, and thus the description thereof is omitted. The above is the description of the first aspect to which the present invention is applied.

Next, a second mode to which the present invention is applied will be described.

FIG. 29 is a diagram showing an overall image of the second mode. In the second mode, a specific check mark 182 for verifying the validity of the decryption of the encrypted image 183 is added to an arbitrary place in the area 181 to be encrypted before the encryption process (see FIG. 29 (A)) encryption is performed ((B) in FIG. 29), and if the check mark 182 added in advance after decrypting the encrypted image 183 is detected from the decrypted image 184, it is decrypted as correctly decrypted. The processing is terminated ((C) in FIG. 29). When the check mark 182 is not detected ((D) in FIG. 29), the encryption position is corrected, and the decryption process is repeated until the check mark 182 is detected or until a specified criterion is satisfied.

FIG. 30 is a diagram showing an outline of the encryption processing in the second mode. 30, the encryption unit 11B includes an encryption area determination unit 31, a check mark addition unit 192, an image conversion unit 32, and a pixel value conversion unit 33.

As in the first mode, the encryption area designating unit 31 selects an area to be encrypted from the input image including the area to be encrypted.

Then, the check mark adding unit 192 adds a specific check mark 182 for verifying the validity of the decryption of the encrypted image 183 to an arbitrary place in the area 181 to be encrypted. It is desirable to add the check mark 182 to a flat region having a pixel distribution with as little image information as possible.

After adding the check mark 182 to the designated position, the area 181 to be encrypted and the encryption key are input in the image conversion unit 32 and the area 181 to be encrypted by the conversion method corresponding to the encryption key, as in the first mode. The image is visually converted, and the pixel value conversion unit 33 converts the pixels in the processed image converted by the image conversion unit 32 at regular intervals so that the converted image forms a substantially grid-like striped pattern. To.

FIG. 31 is a diagram showing an outline of the decoding process in the second mode. In FIG. 31, the decryption unit 14B includes an encryption area detection unit 201, an encryption position detection unit 143, an image reverse conversion unit 144, a check mark detection unit 204, and an encryption position correction unit 205.

First, the encryption area detection unit 201 detects a rough area of the encrypted image 183. Since the pixel distribution of the encrypted image 183 is approximately checkered by the encryption processing of the encryption unit 11B, performing frequency analysis such as FFT in the horizontal direction and the vertical direction respectively corresponds to the fringe period. The power of the frequency becomes remarkably strong.

FIG. 32 is a diagram for explaining an encryption area detection method. As shown in (A) of FIG. 32, when the encrypted image 211 is subjected to frequency analysis, as shown in (B), a region where the power of a certain frequency (a frequency that is an integer multiple of the frequency) protrudes is expressed as “periodicity”. It is expressed as “strong” 214. Since the periodicity of the pixel distribution tends to be strong in the encryption area, it is possible to detect the approximate encryption area and period of the striped pattern.

Returning to the explanation of FIG. The encryption position detection unit 143 identifies a rough area for encryption by the encryption area detection unit 201, and then more accurately detects the encryption area, and at the same time, detects the detailed position of each pixel in the encryption area. To do. As an example of position detection, first, a boundary position (offset) of pixel value conversion is obtained from the period of the striped pattern obtained by the encryption area detection unit 201 and the distribution of pixel absolute value difference, and the pixel absolute value difference is further relative from there. A method of narrowing a large area can be considered. In addition, as with the encrypted position detection unit 143 of the first aspect, it is possible to use Hough transform for detecting the encrypted position.

FIG. 33 is a diagram for explaining a method of detecting the encryption position (horizontal direction). When the encryption area detection process as described above is performed in the horizontal and vertical directions, the encrypted position 221 is detected as shown in FIG.

Returning to the explanation of FIG. The image inverse transform unit 144 performs the same method as the first mode using the encrypted position information and the decryption key, and generates a decrypted image.

The check mark detection unit 204 attempts to detect a check mark from the decoded image decoded by the image inverse conversion unit 144. Since the detection method is the same as the marker detection process in the first aspect, the description is omitted. If a check mark is detected, a decoded image is output and the process is completed. If the check mark is not detected, the encryption position correction unit 205 corrects the encrypted position, and repeats the decryption process (image reverse conversion process) until the check mark is detected or until the specified standard is satisfied.

FIG. 34 is a diagram showing an example of erroneous detection of the encrypted position. As shown in FIG. 34, a case where the end of the encrypted image is overlooked (missing line 231) can be considered. Therefore, when the detection of the check mark 221 fails, the lines indicating the encryption position are added or deleted at the left and right ends and the upper and lower ends, and image reverse conversion processing is performed to determine whether the check mark 221 can be detected. consider. If the check mark 221 cannot be detected no matter how the line is added or deleted, the process ends without outputting the decoded image. The above is the description of the second aspect to which the present invention is applied.

Next, a third mode to which the present invention is applied will be described. In the third embodiment of the present invention, an image using both the positioning marker for specifying the encryption area shown in the first mode and the check mark for determining the validity of the decrypted image of the second mode. Encrypt / decrypt. By using these two types of positioning markers for position detection and check marks for confirming the decrypted image, it is possible to reduce image decryption errors when a correct decryption key is input.

FIG. 35 is a diagram showing an outline of the encryption processing in the third mode. 35, the encryption unit 11C includes an encryption area determination unit 31, a check mark addition unit 192, an image conversion unit 32, a pixel value conversion unit 33, and a marker addition unit 34.

First, an image area to be encrypted is selected by the encryption area specifying unit 31, and a check mark for decryption verification is added by the check mark adding unit 192 in the same manner as in the second mode. After adding the check mark, the image conversion unit 32 and the pixel value conversion unit 33 perform image processing in the same manner as in the first aspect 1 and 2 to encrypt the image, and the marker addition unit 34 detects the encrypted area. A positioning marker is added in the same manner as in the first embodiment. Since the contents of these processes are the same as those in the first aspect or the second aspect, description thereof is omitted.

FIG. 36 is a diagram showing an outline of the decoding process in the third mode. 36, the decryption unit 14C includes a marker detection unit 141, an encryption area detection unit 142, an encryption position detection unit 143, an image reverse conversion unit 144, a check mark detection unit 204, and an encryption position correction unit 205. Yes.

First, the marker detection unit 141 detects a positioning marker by the same method as the first mode, and the subsequent encryption region detection unit 142 detects the encryption region by the same method as the first mode. Further, the encrypted position detection unit 143 detects the detailed position of each pixel in the encryption area by the same method as in the first mode. In addition, the processing procedures executed by the image reverse conversion unit 144, the check mark detection unit 204, and the encrypted position correction unit 205 are the same as those in the second mode, and thus description thereof is omitted. The above is the description of the third aspect to which the present invention is applied.

Claims (11)

1. An information processing apparatus connected to a display device,
   A display element displayed in a part of a display area of the display device, wherein at least a part of the display element is transparently displayed so that display information covered by the display element is visible Transparent display element display means for displaying the element on the display device;
   Of the display information displayed in the display area, information acquisition means for acquiring display information covered by the transparent display element as a digital image;
   Encryption means for encrypting the digital image acquired by the information acquisition means based on an encryption key;
   An encrypted image output means for outputting the encrypted image so that the encrypted image encrypted by the encryption means is displayed instead of the display information covered by the transparent display element;
   An information processing apparatus comprising:
2. The encrypted image output means is output so as to replace the display information for an application that displays the display information covered by the transparent display element.
   The information processing apparatus according to claim 1.
3. The display information is associated with display position information for specifying a display position in a display area of the display device,
   The transmissive display element display means associates the transmissive display element with display position information for specifying a display position in the display area, and causes the display device to display the display position information.
   The information acquisition means acquires the display information covered by the transparent display element based on the display position information of the information and the display position information of the transparent display element;
   The information processing apparatus according to claim 1 or 2.
4. The information acquisition means includes display position information associated with the transparent display element, the display position identified using the display position information associated with the display information among the display information displayed in the display area. By extracting display information that overlaps the display position specified by using the display information covered by the transparent display element,
   The information processing apparatus according to any one of claims 1 to 3.
5. An input receiving means for receiving an input for instructing a display position of the transparent display element;
   The transparent display element display means displays the transparent display element at a display position based on an instruction received by the input receiving means;
   The information processing apparatus according to any one of claims 1 to 4.
6. An information processing apparatus connected to a display device,
   A display element displayed in a part of a display area of the display device, wherein at least a part of the display element is transparently displayed so that display information covered by the display element is visible Transparent display element display means for displaying the element on the display device;
   Among the display information displayed in the display area, information acquisition means for acquiring display information covered by the transparent display element as an encrypted image;
   Decryption means for decrypting the encrypted image acquired by the information acquisition means based on a decryption key;
   In place of the display information covered by the transparent display element, decoded information output means for outputting the decoded information so that the decoded information decoded by the decoding means is displayed;
   An information processing apparatus comprising:
7. The decoded information output means is output so as to replace the display information with respect to a file including display information covered by the transparent display element.
   The information processing apparatus according to claim 6.
8. To the computer connected to the display device,
   A display element displayed in a part of a display area of the display device, wherein at least a part of the display element is transparently displayed so that display information covered by the display element is visible A transparent display element display step for displaying the element on the display device;
   Among the display information displayed in the display area, an information acquisition step of acquiring display information covered by the transmissive display element as a digital image;
   An encryption step of encrypting the digital image acquired in the information acquisition step based on an encryption key;
   An encrypted image output step for outputting the encrypted image so that the encrypted image encrypted in the encryption step is displayed instead of the display information covered by the transparent display element;
   An image processing method for executing
9. To the computer connected to the display device,
   A display element displayed in a part of a display area of the display device, wherein at least a part of the display element is transparently displayed so that display information covered by the display element is visible A transparent display element display step for displaying the element on the display device;
   Among the display information displayed in the display area, an information acquisition step of acquiring display information covered by the transparent display element as an encrypted image;
   A decryption step of decrypting the encrypted image acquired in the information acquisition step based on a decryption key;
   A decoded information output step for outputting the decoded information so that the decoded information decoded in the decoding step is displayed instead of the display information covered by the transparent display element;
   An image processing method for executing
10. By being executed by a computer connected to a display device, the computer is
    A display element displayed in a part of a display area of the display device, wherein at least a part of the display element is transparently displayed so that display information covered by the display element is visible Transparent display element display means for displaying the element on the display device;
    Of the display information displayed in the display area, information acquisition means for acquiring display information covered by the transparent display element as a digital image;
    Encryption means for encrypting the digital image acquired by the information acquisition means based on an encryption key;
    An encrypted image output means for outputting the encrypted image so that the encrypted image encrypted by the encryption means is displayed instead of the display information covered by the transparent display element;
    Image processing program to function as
11. By being executed by a computer connected to a display device, the computer is
    A display element displayed in a part of a display area of the display device, wherein at least a part of the display element is transparently displayed so that display information covered by the display element is visible Transparent display element display means for displaying the element on the display device;
    Among the display information displayed in the display area, information acquisition means for acquiring display information covered by the transparent display element as an encrypted image;
    Decryption means for decrypting the encrypted image acquired by the information acquisition means based on a decryption key;
    Decoded information output means for outputting the decoded information so that the decoded information decoded by the decoding means is displayed instead of the display information covered by the transparent display element;
    Image processing program to function as

Images