JP5880132B2 - Image detection apparatus, information display apparatus, image forming apparatus, and program - Google Patents

Description

  The present invention relates to an image detection apparatus, an information display apparatus, an image forming apparatus, and a program.

  Patent Document 1 discloses code information determination means for specifying a code information image portion included in print data, reversible compression means for reversibly compressing the specified code information image portion data, and the reversibly compressed code information image. Reversible storage means for retaining copy data, reversible decompression means for reversibly decompressing the retained code information image part data, and composition for drawing the reversibly decompressed code information image part data and expanding it into a print page image There is disclosed a printing apparatus comprising: means; and printing means for printing the printing page image on a medium.

  Patent Document 2 discloses a document image acquisition unit that acquires a document image obtained by converting an electronic document into a binary image, an information image acquisition unit that acquires an information image obtained by converting predetermined information into a binary image, the document image, There has been disclosed an image generating apparatus characterized by comprising a synthesizing unit for synthesizing the document image and the information image by performing an exclusive OR operation with the information image.

  Patent Document 3 discloses a trajectory acquisition apparatus for acquiring a trajectory of an indicator on a medium having a machine-readable code formed on a surface, the image input means for continuously reading partial images on the medium, and the image Position information acquisition means for decoding machine-readable code included in the partial image read by the input means to acquire position information of the partial image on the medium, and a plurality of partial images read continuously by the image input means There is disclosed a trajectory acquisition apparatus comprising: a movement information acquisition unit that acquires movement information from a storage unit; and a storage unit that accumulates information acquired by the position information acquisition unit and the movement information acquisition unit.

JP 2006-082339 A JP 2007-329634 A JP 2006-079391 A

  An object of the present invention is to provide an image detection device, an information display device, and an information display device capable of detecting an undecodable area where the code cannot be decoded after the image formation before the document image is superimposed on the paper on which the code image is formed in advance. To provide an image forming apparatus and a program.

  In order to achieve the above object, the invention according to claim 1 is a first acquisition means for acquiring a code image printed on paper and characteristic information relating to an absorption wavelength of the code image, and decoding of a code portion of the code image. A second acquisition unit that acquires a reading unit necessary for the image acquisition, a third acquisition unit that acquires a document image of an electronic document that is an image forming target, and a reading unit of the code image acquired by the second acquisition unit. Based on the dividing unit that divides the document image acquired by the third acquiring unit into a plurality of blocks corresponding to the reading unit, and the characteristic information of the code image acquired by the first acquiring unit, Detection means for detecting, as an undecodable block, an image portion using a color having an absorption band in the absorption wavelength of the code image of the document image and a block where the code portion of the code image overlaps That is the image detecting device.

  According to a second aspect of the present invention, the code image includes an infrared absorbing material, and the image portion of the document image is a black image portion formed of a black color material that absorbs infrared rays. This is an image detection apparatus.

  According to a third aspect of the present invention, whether or not the image portion uses a color having an absorption band in the absorption wavelength of the code image is determined based on color information of each pixel of the document image. Or it is an image detection apparatus of 2.

  The invention described in claim 4 is formed on a sheet, and fourth acquisition means for acquiring the document image and the undecodable block from the image detection apparatus according to any one of claims 1 to 3. Display means for displaying a pre-confirmation screen for confirming an image in advance, and the display means so as to display on the display means whether or not it is the undecodable block together with the document image obtained by the fourth obtaining means. Display control means for controlling the information display device.

  According to a fifth aspect of the present invention, the display control means converts a plurality of pixels other than the image portion in the block to a predetermined color and displays whether or not the block is an undecodable block. It is an information display apparatus of description.

  According to a sixth aspect of the present invention, when the undecodable block is detected, the document image is subjected to color conversion processing so that the image portion is formed of a color material that does not absorb light having an absorption wavelength of the code image. 6. The color conversion means for performing the above-described processing is further provided, and the display control means controls the display means so as to display a document image after color conversion processing by the color conversion means. Information display device.

  According to a seventh aspect of the present invention, there is provided fifth acquisition means for acquiring the document image and the undecodable block from the image detection apparatus according to any one of the first to third aspects, and forming an image on a sheet. An image forming unit that controls the image forming unit to display on the image forming unit whether or not the undecodable block is displayed together with the document image acquired by the fifth acquiring unit. An image forming apparatus.

  According to the eighth aspect of the present invention, the computer obtains the code image printed on the sheet and the characteristic information relating to the absorption wavelength of the code image, and the reading unit necessary for decoding the code portion of the code image. Based on the second acquisition unit to acquire, the third acquisition unit to acquire the document image of the electronic document to be image formed, and the reading unit of the code image acquired by the second acquisition unit, the third acquisition unit Based on the characteristic information of the code image acquired by the dividing means for dividing the acquired document image into a plurality of blocks corresponding to the reading unit and the first acquiring means, absorption of the code image of the document image A program that functions as a detection unit that detects a block in which an image portion using a color having an absorption band at a wavelength and a code portion of the code image overlap as an undecodable block It is.

  According to the first and eighth aspects of the present invention, it is possible to detect an indecipherable region where the code cannot be decoded after the image is formed before the document image is superimposed on the paper on which the code image is previously formed.

  According to the second aspect of the present invention, when the black image portion is formed using a black color material that absorbs infrared rays, it is possible to detect a non-decodable area where the code cannot be decoded after image formation.

  According to the third aspect of the present invention, it is possible to determine whether or not the image portion uses a color having an absorption band in the absorption wavelength of the code image based on the color information of each pixel of the document image.

  According to the fourth aspect of the present invention, the undecodable area can be confirmed by screen display or the like.

  According to the fifth aspect of the present invention, the undecodable area and the other areas can be distinguished and displayed by color.

  According to the invention described in claim 6, when the image portion using a color having an absorption band in the absorption wavelength of the code image is formed of a color material that does not absorb light having the absorption wavelength of the code image, the image It is possible to confirm in what color the part is formed with a screen display or the like.

  According to the seventh aspect of the present invention, the undecodable area can be confirmed by forming an image.

1 is a schematic diagram showing the overall configuration of an image forming system (A) is a top view which shows the whole image of a code addition paper. (B) is a partially enlarged view showing a part of the surface of the code-added paper in an enlarged manner. It is a schematic diagram which shows an example of the unit pattern which comprises a code image. It is a schematic diagram which shows an example of the layout of the unit pattern in a code pattern. It is a schematic diagram for demonstrating the principle which decodes specific information from a code image. It is a block diagram which shows the electric constitution of a terminal device. It is a schematic diagram which shows the reception screen of "add code image". It is a flowchart which shows the processing routine of a "decoding possibility confirmation process." 10 is a flowchart illustrating a processing routine of “preview screen display processing”. (A) is a top view which shows an example of a document image. (B) is a partially enlarged view showing a part of a document image in an enlarged manner. FIG. 6 is a partially enlarged view showing a part of a document image (preview image) after image processing displayed on a print preview screen in an enlarged manner. 7 is a flowchart illustrating a processing routine of “color conversion simulation processing”. FIG. 6 is a partial enlarged view showing a part of a document image (preview image) after reverse color conversion processing displayed on a print preview screen in an enlarged manner. It is a top view which shows an example of the printed matter on which the undecodable area was displayed with the document image. (A)-(D) are the schematic diagrams which show a conventionally well-known dot code.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

<Image forming system>
First, an example of an image forming system according to the present embodiment will be described.
FIG. 1 is a schematic diagram showing the overall configuration of the image forming system. As shown in FIG. 1, the image forming system 10 includes a terminal device 20, an image forming device 30, and a document management server 40. The terminal device 20, the image forming apparatus 30, and the document management server 40 are connected by a communication line 90 such as a LAN (Local Area Network). The terminal device 20 is an information processing device such as a computer used by a user and a peripheral device. The image forming apparatus 30 is a printing apparatus or the like that forms an image on a sheet. The document management server 40 is an information processing apparatus such as a computer that manages electronic documents. The configuration of the image forming system is an example, and the present invention is not limited to this.

  The terminal device 20 acquires an electronic document from the document management server 40 and instructs the image forming apparatus 30 to print the electronic document. In response to a print instruction from the terminal device 20, the image forming apparatus 30 forms a document image of an electronic document on the paper 50, and outputs a printed material 60 on which the document image is formed. Note that the terminal device 20 may acquire an electronic document from the storage unit of the terminal device 20. Further, the terminal device 20 may acquire an electronic document from an external device other than the document management server 40 via the communication unit of the terminal device 20.

  In the present embodiment, when a document image is formed by the image forming apparatus 30, a sheet 50 on which a code image is printed in advance is used. Hereinafter, it is referred to as a code-added paper 50.

  The code image is an image including code information in which specific information is represented by a code pattern (code). As the code pattern (code), a one-dimensional code such as a barcode, a two-dimensional code such as a QR code (registered trademark) or a glyph code, or the like may be used. The specific information is decoded (decoded) by reading the code pattern of the code image. In the present embodiment, an example will be described in which position information indicating a position on a sheet, code information indicating identification information for identifying a sheet, and the like are embedded in a code image. Details of the code image will be described later.

  For example, the code image may be an infrared image formed of an infrared absorbing material. Here, the “infrared image” is an image that is difficult to be visually recognized by the naked eye under natural light or white light, and is read by detecting the reflected infrared light by irradiating the infrared light. Infrared images are read using a dedicated infrared imaging device such as an infrared camera. As the infrared absorbing material, a material having a light absorption peak in an infrared region from a wavelength of 750 nm to a wavelength of 1000 nm is used. Therefore, infrared rays having a wavelength corresponding to the absorption characteristics of the infrared absorbing material are used for reading the infrared image. As such an infrared absorbing material, a known material is appropriately selected. For example, the materials described in JP 2009-209297 A may be employed.

  The image forming apparatus 30 uses a printing color material that absorbs in the visible region, such as ink or toner that develops in cyan (C color), magenta (M color), yellow (Y color), and black (K color). Then, a document image (visible image) is formed on the code-added paper 50. Therefore, when the code image is an infrared image, a printed material 60 is generated in which a document image that is a visible image is superimposed on a code image that is an infrared image. The black color material that develops black (K color) contains carbon black and absorbs infrared rays in the same manner as the infrared absorbing material.

  If the document image includes a black image portion and the black image portion is formed of a black color material, the black image is superimposed on the code image. The portion where the black image is superimposed on the code image becomes an “undecodable area” where the code image and the code information cannot be read and the specific information cannot be decoded.

  A similar problem occurs when the code image is not an infrared image. When the code image is formed of a color material having a predetermined absorption wavelength, the code image cannot be read if an image portion using a color having an absorption band at the same absorption wavelength is superimposed on the code image. It becomes an undecryptable area. For example, if the code image is a blue image formed with a C color material, the code image cannot be read if the document image is formed with “blue” or “black” having an absorption band at the absorption wavelength of the C color material. . Table 1 below illustrates the relationship between the color of the color material that forms the code image and the color that makes the code image unreadable.

  In the present embodiment, before instructing the image forming apparatus 30 to print an electronic document, the terminal device 20 executes a “decryptability confirmation process” to be described later to detect a non-decryptable area generated in the printed material 60. . Accordingly, the terminal device 20 functions as an “image detection device” that detects an undecodable area. In addition, the detected undecodable area is displayed to the user. Note that the decryption permission / inhibition confirmation process is executed according to an instruction from the user.

  Although the detailed configuration of the terminal device 20 will be described later, a display unit such as a display is connected to the terminal device 20 in order to display various screens. The terminal device 20 controls the operation of displaying a screen on the display unit. Accordingly, the terminal device 20 functions as an “information display device” including a display unit and a display control unit. Although details will be described later, in the decryption permission confirmation process, a “preliminary confirmation screen (print preview screen)” for confirming in advance the document image formed on the printed material 60 is displayed on the display unit of the terminal device 20. . By displaying the undecodable area together with the document image on the prior confirmation screen, the undecodable area is confirmed by the user before the image forming apparatus 30 forms the document image. Alternatively, a print preview image may be printed to check the undecodable area. In addition, an image may be formed in a state where the signal-impossible area is visible so that the user of the image forming medium can determine the signal-impossible area.

  Further, the pen-type device 70 may be used for reading a code image (infrared image) from the printed material 60. The pen-type device 70 includes, for example, a pen tip 72 for writing on the printed matter 60, an infrared-only photographing unit 74 for photographing a code image around the pen tip 72, and decoding hand position information by decoding position information from the photographed code image. An information processing unit (not shown) to be acquired, a storage unit (not shown) that stores position information and handwriting information, a communication unit (not shown) that communicates with the outside by wireless communication, and the like are provided.

  For example, when writing on the printed matter 60 using the pen-type device 70, handwriting information is acquired by the pen-type device 70 and transmitted to the document management server 40. The handwriting information for the printed material 60 is managed by the document management server 40 in association with the electronic document printed on the printed material 60.

<Code-added paper>
Next, the code-added paper used in this embodiment will be described.
FIG. 2A is a plan view showing the entire image of the code-added paper 50. FIG. As shown in FIG. 2A, in this embodiment, a code image (represented by a dot pattern) is printed on the entire surface of the code-added sheet 50 so that the code image can be read from any position on the entire sheet. Has been. The code image may be added to a specific area such as an image forming area in which an image is formed by the image forming apparatus 30 or a peripheral area around the image forming area. Further, a code image may be added to both the front and back sides of the code addition paper 50.

  FIG. 2B is a partially enlarged view showing a part 50 </ b> A of the surface of the code-added paper 50 in an enlarged manner. As shown in FIG. 2B, a code image uses a two-dimensional code (dot pattern) in which a plurality of dots are arranged two-dimensionally as a code pattern. Here, the “dot” is a portion printed with an infrared absorbing material that forms an infrared image, and is represented by a black square (■) in FIG. As the infrared absorbing material, a material having a light absorption peak in an infrared region from a wavelength of 750 nm to a wavelength of 1000 nm is used. Therefore, infrared rays having a wavelength corresponding to the absorption characteristics of the infrared absorbing material are used for reading the infrared image.

  The code image includes a plurality of code patterns 52 arranged two-dimensionally. The code pattern 52 is a reading unit necessary for decoding specific information such as position information and identification information. For example, a QR code (registered trademark) corresponds to one QR code (registered trademark). The specific information is decoded for each code pattern 52. In other words, when a part of the code pattern 52 cannot be read, the specific information corresponding to the code pattern 52 cannot be decoded. In the present embodiment, the code pattern 52 includes a plurality of unit patterns 54, each of the plurality of unit patterns 54 is read, and the specific information corresponding to the code pattern 52 is decoded (see FIGS. 3 and 4). reference).

  FIG. 3 is a schematic diagram showing an example of the unit pattern 54 constituting the code image. The unit pattern 54 is the minimum unit constituting the code pattern 52 and expresses 1-bit or multiple-bit information. As shown in FIG. 3, the unit pattern 54 is divided into a dot arrangement area (black area 56A and gray area 56B) where dots are arranged and a non-arrangement area (white area 56C) where dots are not arranged. The black area 56A indicates that dots are arranged in the dot arrangement area. The gray area 56B indicates that no dot is arranged in the dot arrangement area.

In the example shown in FIG. 3, nine dot arrangement areas are provided in the unit pattern 54. Dots are arranged at two locations selected from these nine locations. Since there are 36 combinations (= ₉ C ₂ ) for selecting two places out of nine places, there are 36 types of unit patterns 54. This unit pattern 54 is referred to as a “9C2 pattern”. For example, by using 32 types of unit patterns 54 among them, 5-bit information is expressed. In the example illustrated in FIG. 3, the size of the unit pattern 54 is “12 pixels × 12 pixels”. The size of each of the dot arrangement area (black area 56A and gray area 56B) and the non-arrangement area (white area 56C) is “2 pixels × 2 pixels”.

  For example, when a code image having the unit pattern 54 is printed using an image forming apparatus having a resolution of 600 dpi (resolution capable of printing 600 pixels per inch), the size of one pixel is “42.3 μm”. × 42.3 μm ”. Accordingly, the size of one dot of the unit pattern 54 is “84.6 μm × 84.6 μm”. The smaller the size of one dot, the larger the amount of information per unit area. However, if the size of one dot is too small, the reading accuracy is lowered. The size of one dot constituting the unit pattern 54 is preferably in the range of 50 μm to 100 μm in length (diameter) on one side in consideration of the amount of information to be expressed, reading accuracy, resolution of the image forming apparatus, and the like.

  FIG. 4 is a schematic diagram showing an example of the layout of the unit pattern 54 in the code pattern 52. The code pattern 52 is composed of a plurality of unit patterns 54 arranged two-dimensionally. Here, the position where the unit pattern 54 is arranged is referred to as a “unit block”. In the example shown in FIG. 4, 25 (= 5 × 5) unit blocks are arranged. A unit pattern 54 is arranged in each of the 25 unit blocks. As described above, there are 36 types of unit patterns 54. In the example shown in FIG. 4, four types of unit patterns 54 are used as synchronization codes for detecting image rotation, and the remaining 32 types of unit patterns 54 are used as identification codes or position codes.

  In the layout shown in FIG. 4, a synchronization code 54 </ b> A is disposed in the upper left unit block of the code pattern 52. In four unit blocks arranged on the right side of the synchronization code 54A, an X position code 54B representing the X coordinate is arranged. In four unit blocks arranged below the synchronization code 54A, a Y position code 54C representing the Y coordinate is arranged. In addition, an identification code 54D is arranged in 16 (= 4 × 4) unit blocks in an area surrounded by the X position code 54B and the Y position code 54C. FIG. 4 shows an example of the layout of the unit pattern 54, and each of the synchronization code 54A, the X position code 54B, the Y position code 54C, and the identification code 54D is replaced with one of the unit patterns 54.

Here, the decoding principle in units of code patterns will be briefly described.
FIG. 5 is a schematic diagram for explaining the principle of decoding specific information from a code image. As shown in FIG. 5, a frame 58 having the same size as the code pattern 52 is superimposed on the dot array 50 </ b> B read from a part 50 </ b> A of the code image. The frame 58 has a plurality of openings having the same size as the unit block. The plurality of openings are arranged in the same layout as the unit block. While moving the frame 58 with respect to the dot array 50B, the position of the frame 58 is adjusted so that the number of dots in each opening becomes two. Thereby, a dot arrangement corresponding to one code pattern 52 is detected.

  When the dot array corresponding to the code pattern 52 is detected, the synchronization code 54A is detected from the detected dot array, and the rotation of the image is determined. The dot array is rotated according to the determination result, and the dot array is set in the correct orientation. As a result, a regular dot arrangement in which the unit patterns 54 are arranged in the same layout as the code pattern 52 is acquired. Next, the unit pattern 54 corresponding to each of the X position code 54B, the Y position code 54C, and the identification code 54D is detected from the acquired regular dot array, and the position information and the identification information are decoded.

  When the decoding process for one code pattern 52 is completed, the frame 58 is moved in the direction of arrow A with respect to the dot array 50B, the dot array corresponding to the next code pattern 52 is detected, the above procedure is repeated, and the next procedure is repeated. The position information and the identification information are decoded from the code pattern 52. Thereby, position information and identification information are decoded for every code pattern 52. The frame 58 moves according to the order in which the code pattern 52 is read. For example, when handwriting information is acquired by the pen-type device 70, the moving direction of the frame 58 is the moving direction of the pen tip 72.

<Configuration of terminal device>
Next, the electrical configuration of the terminal device 20 will be described.
FIG. 6 is a block diagram showing an electrical configuration of the terminal device 20. As shown in FIG. 6, the terminal device 20 is an information processing device such as a computer and a peripheral device, and communicates with the information processing device 20A, a display unit 22 such as a display, an input unit 24 such as a mouse and a keyboard, and an external device. A communication unit 26 that functions as an interface for performing the operation and a storage unit 28 such as a hard disk are provided.

  The information processing apparatus 20A includes a CPU (Central Processing Unit) 20B, a ROM (Read Only Memory) 20C storing various programs, a RAM (Random Access Memory) 20D used as a work area when executing the programs, A nonvolatile memory 20E for storing information and an input / output interface (I / O) 20F are provided. Each of the CPU 20B, ROM 20C, RAM 20D, nonvolatile memory 20E, and I / O 20F is connected via a bus 20G.

  Each unit of the display unit 22, the input unit 24, the communication unit 26, and the storage unit 28 is connected to the I / O 20F of the information processing apparatus 20A. The information processing apparatus 20A controls the display unit 22, the input unit 24, the communication unit 26, and the storage unit 28, and performs various calculations. In the present embodiment, a case will be described in which a control program for executing a “decoding availability confirmation process” described later is stored in the storage unit 28 in advance. The control program stored in advance is read from the storage unit 28 by the CPU 20B and executed. The control program may be stored in another storage device such as the ROM 20C.

  Various drives may be connected to the information processing apparatus 20A. Each type of drive is a device that reads data from a computer-readable portable recording medium such as a flexible disk, a magneto-optical disk, or a CD-ROM, and writes data to the recording medium. When various types of drives are provided, a control program may be recorded on a portable recording medium, and this may be read and executed by a corresponding drive.

<Decryptability confirmation process>
Next, the “decryptability confirmation process” will be described.
The user of the terminal device 20 may display a “preliminary confirmation screen” on the display unit 22 and confirm the document image formed on the printed matter 60 in advance before instructing the printing of the electronic document. Hereinafter, the operation for displaying the advance confirmation screen is referred to as “print preview”, and the advance confirmation screen is referred to as “print preview screen”. In the print preview, by operating the input unit 24, various simulation operations (simulation) such as background setting are executed. In the present embodiment, a case where a simulation operation of “add code image” is performed in print preview will be described.

(Reception screen for adding code images)
FIG. 7 is a schematic diagram showing a reception screen for “add code image”. When the user of the terminal device 20 operates the input unit 24 to instruct to perform a “code image addition” simulation operation, a reception screen 80 illustrated in FIG. 7 is displayed. The reception screen 80 includes a setting unit 82A for setting “paper size”, a setting unit 82B for setting “resolution” of the image forming apparatus, a selection unit 84A for selecting “display preview screen”, A selection unit 84B for selecting “execution of color conversion simulation”, an instruction unit 86A for instructing “start (OK)”, and an instruction unit 86B for instructing “cancel (cancel)” are provided. Yes. When the user operates the input unit 24 and inputs information to each part of the reception screen 80, setting information, selection information, and instruction information are acquired.

  In this embodiment, the code-added paper 50 is stored in the paper storage unit of the image forming apparatus 30 for each paper size. A predetermined code image is printed on the code-added paper 50 in accordance with the resolution of the image forming apparatus 30 and the paper size. Accordingly, the code image printed on the code-added paper 50 is uniquely obtained according to the resolution of the image forming apparatus 30 and the paper size.

  In the present embodiment, a plurality of code images are stored in advance in the storage unit 28 of the terminal device 20 in association with the paper size and resolution. The storage unit 28 of the terminal device 20 stores “reading units” necessary for decoding the two-dimensional code included in the code image in accordance with each of the plurality of code images. When “paper size” is set by the setting unit 82A of the reception screen 80 for “add code image” and “resolution” is set by the setting unit 82B, the code is printed on the code-added paper 50 from a plurality of code images. A code image is obtained.

  The image forming apparatus 30 acquires print parameters from the terminal device 20 together with a print instruction and image information of the electronic document. The print parameter is a print attribute such as a page, the number of copies, a paper size, the number of pages to be printed on one sheet, and a margin. The image forming apparatus 30 selects a code-added paper 50 having a paper size corresponding to the print parameter, and forms a document image of the electronic document on the selected code-added paper 50.

(Outline of decryption permission confirmation process)
FIG. 8 is a flowchart showing a processing routine of “decoding availability confirmation processing”. This decryption permission confirmation process is executed by the CPU 20B of the terminal device 20. The decryption permission / inhibition confirmation process is started when “start” is instructed by the user via the instruction unit 86 </ b> A of the reception screen 80. The “start” instruction is given after the setting and selection by the user is performed in the setting units 82A and 82B and the selection units 84A and 84B of the reception screen 80.

  First, in step 100, based on the selection information acquired from the reception screen 80, it is determined whether or not “display preview screen” has been selected. If the determination is affirmative, the process proceeds to step 102. If the determination is negative, the routine ends. In step 102, “preview screen display processing” is executed. In the preview screen display process, a print preview screen when the electronic document is printed on the code-added paper 50 is displayed on the display unit 22 of the terminal device 20. Although details will be described later, a non-decryptable area is displayed together with the document image on the print preview screen.

  Next, in step 104, based on the selection information acquired from the reception screen 80, it is determined whether or not “execute color conversion simulation” has been selected. If the determination is affirmative, the process proceeds to step 106. If the determination is negative, the routine is terminated. In step 106, “color conversion simulation processing” is executed and the routine is terminated. Although details will be described later, in the color conversion simulation process, the document image after the color conversion process is displayed on the print preview screen.

  The document image after the color conversion process is a document image acquired when the color conversion process is performed as an image process on the original document image. When printing a document image including a black image portion, black color may be expressed by a mixed color of C, M, and Y color materials that do not absorb infrared rays without using K color materials that absorb infrared rays. Good. In this case, color conversion processing is performed to convert RGB format image data into CMY format image data (not CMYK format). In principle, black should be expressed by color mixture, but in the document image after the color conversion processing, black is converted to “purple” or “blue”.

(Preview screen display processing)
Next, the “preview screen display process” will be described. FIG. 9 is a flowchart showing a processing routine of “preview screen display processing”.

  First, in step 200, based on the setting information (“paper size” and “resolution”) acquired from the reception screen 80, a code image corresponding to the setting information from among a plurality of code images stored in the storage unit 28. To get. As a result, a code image corresponding to the code-added paper 50 on which the document image is printed is acquired. The acquired code image is stored in the RAM 20D and read out as necessary.

  Next, in step 202, the “reading unit” stored in the storage unit 28 is acquired according to the acquired code image. The acquired reading unit is stored in the RAM 20D and read out as necessary. In the present embodiment, the code image is an image in which a plurality of code patterns 52 that are “reading units” are arranged. The acquired code image is divided in advance into a plurality of blocks having the size of the code pattern 52 (for example, 60 pixels × 60 pixels).

  Next, in step 204, a document image of an electronic document that is an image formation target is acquired. The acquired document image is stored in the RAM 20D and read out as necessary. Here, the “electronic document that is an image formation target” is an electronic document that is a display target of a print preview.

  Next, in step 206, the acquired document image is divided into a plurality of “blocks” corresponding to the reading unit based on the reading unit of the code image. For example, when a document image for one page is formed on the code-added paper 50, the document image and the code image have the same size. In this case, the acquired document image is divided into a plurality of blocks having the size of the code pattern 52, similarly to the acquired code image. Further, when N pages of document images are formed on the code-added paper 50, the size of the acquired document image is changed according to the magnification of the formed image. For example, when a two-page document image is formed on the code-added paper 50 by halving each document image, the size is twice (approximately 1.41 × 1.41) the code pattern 52. Are divided into a plurality of blocks.

  Next, in step 208, a detection order for detecting “undecodable blocks” is set for a plurality of blocks of the document image. For example, when forming an image, when the paper is viewed in plan, the left and right direction is the main scanning direction, and the arrangement direction of the main scanning lines is the sub-scanning direction, and the images are formed in a predetermined order. First, main scanning for one line is performed from the left side to the right side. Next, the main scanning of the next line is performed by moving in the sub-scanning direction. The detection order may be the same order as the scanning order at the time of image formation. Note that the set detection order is stored in the RAM 20D and read out as necessary.

  In the present embodiment, a code image is printed on the entire surface of the code-added paper 50, and the code image is composed of a plurality of code patterns 52. For this reason, each of the plurality of blocks of the document image overlaps the code pattern 52 of the code image. On the other hand, when a code image is printed on a part of the code-added paper 50, some of the plurality of blocks of the document image do not overlap the code pattern 52. In this case, the detection order may be set for a block that overlaps the code pattern 52 of the code image among a plurality of blocks of the document image.

  Next, in step 210, it is determined whether or not black pixels are included in the first block of the document image. Based on the color information of each pixel in the block, it is determined whether or not a black pixel is included in the block. For example, when the document image is represented by RGB format image data, each pixel in the block has color information representing the brightness of each RGB color according to the number of gradations. When each RGB color is displayed with 256 gradations, the black pixel has color information (R = 0, G = 0, B = 0). In this case, it is only necessary to determine whether or not a pixel having color information (R = 0, G = 0, B = 0) is included in the block. Alternatively, a threshold value may be provided for each of the R value, the G value, and the B value, and a pixel having color information in which each of the R value, the G value, and the B value is equal to or less than the threshold value may be defined as a black pixel.

  In the above example, the case where the document image is RGB format image data will be described. However, the document image may be CMYK format image data. In the case of CMYK format image data, it is only necessary to determine whether a pixel having color information (K> 0) (a pixel in which a K color material is used for printing) is included in the block. When pixels having color information (K> 0) are in a wide range, a threshold value may be provided for the K value, and a pixel having color information having a K value equal to or less than the threshold value may be defined as a black pixel.

  If the document image includes a black image portion and the black image portion is formed of a black color material, the black image is superimposed on the code image. The portion where the black image is superimposed on the code image becomes an “undecodable area” where the code image and the code information cannot be read and the specific information cannot be decoded. Therefore, when a black pixel is included in the block, an affirmative determination is made in step 210 and the process proceeds to step 212. In step 212, the block including the black pixel is recognized as a “non-decodable block”. That is, an undecodable block is detected. The detection result is stored in the RAM 20D and read out as necessary. On the other hand, if no black pixel is included in the block, a negative determination is made in step 210 and the process proceeds to step 214.

  Next, in step 214, it is determined whether or not black pixels are included in the next block of the document image. If a black pixel is included in the block, an affirmative determination is made at step 214 and the routine proceeds to step 216. In step 216, the block including the black pixel is recognized as a “undecodable block”. That is, an undecodable block is detected. The detection result is stored in the RAM 20D and read out as necessary. On the other hand, if no black pixel is included in the block, a negative determination is made in step 214, and the process proceeds to step 218.

  Next, in step 218, it is determined whether or not undecodable blocks have been detected for all the blocks to be detected. In the case of negative determination, the process returns to step 214, and the detection of undecodable blocks is repeated. On the other hand, if the determination is affirmative, the process proceeds to the next step 220.

  Next, in step 220, image processing of the document image is performed so that the detected undecodable block is identified on the image. For example, for a block that cannot be decoded, the image processing of the document image is performed so that the background color of the document image is displayed in a specific color such as gray. Alternatively, image processing such as surrounding a region with a dotted line or reversing light and dark may be used. The document image after the image processing is stored in the RAM 20D and read out as necessary.

  Next, in step 222, the display unit 22 is instructed to display the document image after image processing on the print preview screen, and the routine ends. On the print preview screen, an undecodable area including undecodable blocks is displayed together with the document image. As described above, the undecodable block is displayed so as to be identified on the image. Therefore, for each of the plurality of blocks of the document image, “whether it is a block that cannot be decoded” is displayed so that the user can know.

Here, the contents of the “preview screen display process” will be described visually.
FIG. 10A is a plan view showing an example of a document image. Here, a case where the document image is a “color chart for color adjustment” will be described as an example. As shown in FIG. 10A, in the illustrated document image 100, a black character image 102 such as “test pattern” and a graphic image 104 of C color, M color, Y color, and the like are formed. The document image 100 includes an image portion of a character image 102 and a graphic image 104, and a background portion 106 that is the background of the image. The graphic image 104 is a so-called “test patch”, and is a square solid image of each of C color, M color, and Y color.

  FIG. 10B is a partially enlarged view showing a part 100A of the document image 100 in an enlarged manner. As shown in FIG. 10B, in a portion 100A at the approximate center of the document image 100, a black character image 102 of the character “ma” of the character string “magenta” and one of the M-color graphic image 104 are displayed. Are arranged. In the preview screen display process, the document image is divided into a plurality of blocks corresponding to reading units. When reference numerals are assigned to main blocks, the block 100A of the document image 100 includes blocks 110A, 110B, 110C, 110D, 110E, and 110F.

  FIG. 11 is a partially enlarged view showing a part 200A of a document image (preview image) after image processing displayed on the print preview screen. The preview image portion 200 </ b> A corresponds to the portion 100 </ b> A of the document image 100. In the preview screen display process, a block that cannot be decoded is detected. In this example, the blocks 110A, 110B, 110C, 110D, and 110E overlap the black character image 102, and include black pixels in the block. Therefore, each of the blocks 110A to 110E is detected as an undecodable block.

  In the preview screen display process, the document image is processed so that the detected undecodable block is identified on the image. In addition, the document image after image processing is displayed on the print preview screen. In this example, for the blocks 110A to 110E that are undecodable blocks, the color of the background portion 106 of the document image is converted to gray, and the region display unit 108 that displays the undecodable region is obtained. On the other hand, the color of the background portion 106 of the document image is not converted for the block 110F that does not correspond to the undecodable block.

  As shown in FIG. 11, for an undecodable block, the area display unit 108 is displayed instead of the background unit 106, so that “whether it is an undecodable block” can be known on the print preview screen. Further, by indicating whether or not each of the plurality of blocks is a non-decodable block, the “undecodable area” is displayed.

(Color conversion simulation process)
Next, the “color conversion simulation process” will be described. FIG. 12 is a flowchart showing a processing routine of “color conversion simulation processing”. As shown in FIG. 8, the “color conversion simulation process” is executed subsequent to the “preview screen display process”.

  Note that the document image, the detection result of the undecodable block, and the like have already been acquired in the preview screen display process and stored in the RAM 20D of the terminal device 20. The document image is stored in the RAM 20D as image data in RGB format (hereinafter referred to as “RGB data”).

  In the present embodiment, a “color conversion table” for performing color conversion processing is prepared according to the color space expressed by the image forming apparatus 30. The storage unit 28 of the terminal device 20 stores “first color conversion table” and “second color conversion table” as color conversion tables. The “first color conversion table” is a color conversion table for converting RGB data into CMY format image data (hereinafter referred to as “CMY data”). The “second color conversion table” is a color conversion table for converting RGB data into CMYK format image data (hereinafter referred to as “CMYK data”).

  First, in step 300, a “first color conversion table” and a “second color conversion table” are acquired from the storage unit 28. The acquired information is stored in the RAM 20D and read out as necessary. Next, in step 302, the document image (the document image before being processed in step 220 in FIG. 9) and the detection result of the undecodable block are acquired.

  Next, in step 304, color conversion processing for converting the document image from RGB data to CMY data or CMYK data is executed in accordance with whether or not each block of the document image is a block that cannot be decoded. In the undecodable block of the document image, the RGB data is converted into CMY data using the “first color conversion table”. In blocks other than the undecodable block of the document image, the RGB data is converted into CMYK data using the “second color conversion table”.

  In the CMY format image data, each pixel has color information indicating a mixing ratio of each color of CMY. In addition, in the CMYK format image data, each pixel has color information indicating a mixing ratio of each color of CMYK. In the “undecodable block” of the document image, RGB data is converted into CMY data (not CMYK data). Therefore, at the time of image formation of a document image, black is expressed by a mixed color of C, M, and Y color materials that do not absorb infrared light in the block corresponding to the “undecodable block”.

  Next, in step 306, a reverse color conversion process is performed in which the color-converted document image (CMY data or CMYK data) is converted into RGB data using the “second color conversion table”. The document image after the reverse color conversion process is stored in the RAM 20D and read out as necessary. Next, in step 308, the display unit 22 is instructed to display the document image after the reverse color conversion process on the print preview screen, and the routine ends.

Here, the contents of the “color conversion simulation process” will be described visually.
FIG. 13 is a partially enlarged view showing an enlarged part 200B of the document image (preview image) after the reverse color conversion process displayed on the print preview screen. The preview image portion 200 </ b> B corresponds to the portion 100 </ b> A of the document image 100. In the “color conversion simulation process”, a color conversion process is executed in which the RGB data of the “undecodable block” of the document image is converted into CMY data (not CMYK data). Next, reverse color conversion processing for reversely converting CMYK data and CMY data of the document image into RGB data is executed, and the document image subjected to the reverse color conversion processing is displayed on the print preview screen.

  In this example, the blocks 110A to 110E are “undecodable blocks”. The RGB data of the blocks 110A to 110E is color-converted to CMY data and then reverse-color converted to RGB data. On the print preview screen, a document image corresponding to the RGB data subjected to the reverse color conversion process is displayed. As shown in FIG. 13, the black character image 102 of the document image 100 shown in FIG. 10B is displayed as a character image 102A of purple, blue, etc. (color different from black) in the preview image portion 200B. The In the RGB format, various color representations are possible compared to the CMY format and the CMYK format. Therefore, the document image displayed on the print preview screen is displayed in a color that approximates the color of the document image formed on the paper.

Here, the reason why black color is not reproduced will be briefly described.
When RGB data is color-converted into CMY data, RGB color information (for example, R = 0, G = 0, B = 0) of black pixels includes C color, M color, The color information is converted into CMY color information (K = 0, C = x, M = y, Y = z) represented by a Y color mixing ratio. Even if the obtained CMY data is inversely converted to RGB data, the original RGB color information is not reproduced. For example, CMY color information (K = 0, C = x, M = y, Y = z) is converted into RGB color information (R = a, G = b, B = c) representing purple or blue. It cannot be restored to the original RGB color information (R = 0, G = 0, B = 0) representing the black pixel after conversion.

  As described above, by executing the “color conversion simulation process”, the document image after the color conversion process is displayed on the print preview screen. Therefore, by referring to the print preview screen, when black is expressed by mixing color materials of C, M, and Y without using the K color material, the black image portion of the document image is “what color? You will know in advance whether it will be printed.

  In the above description, an example has been described in which RGB data is converted into CMY data for “undecodable blocks”, and RGB data is converted into CMYK data for blocks other than “undecodable blocks”. Data may be converted into CMY data. In this case, by referring to the print preview screen, it is possible to know in advance what color each image part of the document image is printed.

<Modification>
In the above embodiment, an example in which a document image is displayed on the print preview screen has been described. However, the document image displayed on the print preview screen may be printed on paper. FIG. 14 is a plan view showing an example of a printed material on which an undecryptable area is displayed together with a document image. A preview image shown in FIG. 11 is printed on the printed material 60A.

  As shown in FIG. 14, a K-color character image 62K, a C-color graphic image 64C, an M-color graphic image 64M, and a Y-color graphic image 64Y are formed on the printed material 60A. The background portion 66 is the background portion of these image portions. Further, a gray area display portion 68G indicating the “undecodable area” is arranged in the background of the K-color character image 62K. In the printed matter 60A, since the “non-decryptable area” is clearly indicated by the area display unit 68G, the code image may be read from another area.

  In the above embodiment, the “code pattern” including a plurality of unit patterns has been described as the reading unit. However, the “unit pattern” may be the reading unit. The reading unit may be a size or an area necessary for decoding the specific information, and may be set according to the information amount of the specific information. For example, even when the “unit pattern” according to the present embodiment is used as a reading unit, specific information of 5 bits or more is held.

  In the above embodiment, an example of a dot code that uses a specific unit pattern called “9C2 pattern” as a dot code constituting a code image has been described. However, the unit pattern size and dot arrangement The number of dots to be selected may be changed as appropriate. Also, different types of dot codes may be used. 15A to 15D are schematic views showing conventionally known dot codes. These conventionally known dot codes may be used. The “reading unit” necessary for decoding the specific information is set according to the type of the dot code and the information amount of the specific information.

  In the dot code shown in FIG. 15A, a virtual lattice frame is arranged, and dots are arranged in any one of four regions divided by intersections of the lattice. As a result, four types of patterns can be expressed, and two bits can be expressed (Japanese Patent Publication No. 2003-511762). In the dot code shown in FIG. 15B, one bit is expressed by right and left diagonal lines called glyph codes (Japanese Patent Laid-Open No. 9-185669). Each of the right diagonal line and the left diagonal straight line is composed of a plurality of dots.

  In the dot code shown in FIG. 15C, information is expressed by a combination of a straight line and a key-type graphic pattern (Japanese Patent Laid-Open No. 2004-152273). Each pattern is composed of a plurality of dots. In the dot code shown in FIG. 15D, information is expressed by dot on / off (Japanese Patent No. 2833975).

  In the above embodiment, an example of acquiring an electronic document and its document image stored in advance in an external device has been described. However, the electronic document and its document image may be acquired by other methods. . For example, a document image read by an image reading apparatus such as a scanner unit of the image forming apparatus may be used. For example, when a document image is printed on a code-added sheet with an ink containing a K color material, the printed document image may be read by an image reading device to check an “undecodable area” on the printed matter.

  In the above-described embodiment, an example in which a block including black pixels is a “non-decodable block” has been described. However, the present invention is not limited to this. As described above, when the code image is formed of a color material having a predetermined absorption wavelength, when the image portion using the color having the absorption band at the same absorption wavelength is superimposed on the code image, the code image Becomes an “undecodable area” that cannot be read. In this case, a block including a pixel of a color that makes it impossible to read the code image according to the color of the color material forming the code image is referred to as an “undecodable block”.

  The configurations of the image detection apparatus, the information display apparatus, the image forming apparatus, and the program described in the above embodiments are merely examples, and it goes without saying that the configurations may be changed without departing from the gist of the present invention. Yes. For example, all or some steps of the program may be executed by a circuit corresponding to the step. Further, the order of all or part of the program may be changed.

DESCRIPTION OF SYMBOLS 10 Image forming system 20 Terminal apparatus 20A Information processing apparatus 22 Display part 24 Input part 26 Communication part 28 Storage part 30 Image forming apparatus 40 Document management server 50 Code addition paper 52 Code pattern 54 Unit pattern 54A Synchronization code 54B Position code 54C Position code 54D Identification code 56A Black area 56B Gray area 56C White area 58 Frame 60 Printed matter 62K Character image 68G Area display part 70 Pen type device 80 Reception screen 82A Setting part 82B Setting part 84A Selection part 84B Selection part 86A Instruction part 86B Instruction part 90 Communication Line 100 Document image 102 Character image 104 Graphic image 106 Background portion 108 Area display portions 110A to 110F Block

Claims (8)

First acquisition means for acquiring characteristic information relating to the code image printed on the paper and the absorption wavelength of the code image;
Second acquisition means for acquiring a reading unit necessary for decoding the code portion of the code image;
Third acquisition means for acquiring a document image of an electronic document to be imaged;
A dividing unit configured to divide the document image acquired by the third acquiring unit into a plurality of blocks corresponding to the reading unit based on the reading unit of the code image acquired by the second acquiring unit;
A block in which an image portion using a color having an absorption band at an absorption wavelength of the code image of the document image and a code portion of the code image overlap based on the characteristic information of the code image acquired by the first acquisition means Detecting means for detecting as an undecodable block;
An image detection apparatus.   The image detection apparatus according to claim 1, wherein the code image includes an infrared absorbing material, and the image portion of the document image is a black image portion formed of a black color material that absorbs infrared rays.   The image detection apparatus according to claim 1, wherein whether or not the image portion uses a color having an absorption band in an absorption wavelength of the code image is determined based on color information included in each pixel of the document image. A fourth acquisition unit that acquires the document image and the undecodable block from the image detection device according to any one of claims 1 to 3,
Display means for displaying a prior confirmation screen for confirming in advance the image formed on the paper;
Display control means for controlling the display means to display on the display means whether or not the document image acquired by the fourth acquisition means is the undecodable block;
An information display device.   The information display device according to claim 4, wherein the display control unit converts a plurality of pixels other than the image portion in the block to a predetermined color and displays whether or not the block is an undecodable block. A color conversion unit that performs color conversion processing of the document image so that the image portion is formed of a color material that does not absorb light having an absorption wavelength of the code image when the undecodable block is acquired; ,
The display control means controls the display means so as to display a document image after color conversion processing by the color conversion means;
The information display device according to claim 4 or 5. A fifth acquisition unit that acquires the document image and the undecodable block from the image detection device according to any one of claims 1 to 3.
Image forming means for forming an image on paper;
Image forming control means for controlling the image forming means to display on the image forming means whether or not it is the undecodable block together with the document image obtained by the fifth obtaining means;
An image forming apparatus. Computer
First acquisition means for acquiring characteristic information relating to the code image printed on the paper and the absorption wavelength of the code image;
Second acquisition means for acquiring a reading unit necessary for decoding the code portion of the code image;
Third acquisition means for acquiring a document image of an electronic document to be imaged;
A dividing unit configured to divide the document image acquired by the third acquiring unit into a plurality of blocks corresponding to the reading unit based on the reading unit of the code image acquired by the second acquiring unit;
A block in which an image portion using a color having an absorption band at an absorption wavelength of the code image of the document image and a code portion of the code image overlap based on the characteristic information of the code image acquired by the first acquisition means Detecting means for detecting as an undecodable block,
Program to function as.