Abstract:
An image processing apparatus includes: a noise position information obtaining unit that obtains noise position information regarding positions of noise in an image read by a reading unit that optically reads a surface of a medium, an image generating unit that generates a noise eliminated image that is obtained by eliminating a noise from the image, a pattern information obtaining unit that obtains pattern information indicating a pattern appearing on the surface of the medium from the noise eliminated image, and a pattern information registering unit that registers the pattern information obtained from areas set on the basis of the noise position information in the noise eliminated image.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2010-197899 filed on Sep. 3, 2010. 
     BACKGROUND 
     Technical Field 
     The present invention relates to an image processing apparatus and computer readable medium. 
     SUMMARY 
     According to an aspect of the invention, an image processing apparatus includes: a noise position information obtaining unit that obtains noise position information regarding positions of noise in an image read by a reading unit that optically reads a surface of a medium, an image generating unit that generates a noise eliminated image that is obtained by eliminating a noise from the image, a pattern information obtaining unit that obtains pattern information indicating a pattern appearing on the surface of the medium from the noise eliminated image, and a pattern information registering unit that registers the pattern information obtained from areas set on the basis of the noise position information in the noise eliminated image. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a view illustrating a general outline of a configuration of an image processing apparatus according to a first embodiment of the present invention; 
         FIG. 2  is a view illustrating a configuration of the reading section of the image processing apparatus; 
         FIG. 3  is a view functionally illustrating a configuration of the control section of the image processing apparatus; 
         FIG. 4  is a view showing an example of a general outline of the processing executed by the paper fingerprint information registration section of the control section; 
         FIG. 5  is a view illustrating the flow of the registration processing of the image processing apparatus according to the first embodiment; 
         FIG. 6  is a view showing another example of a general outline of the processing executed by the paper fingerprint information registration section; 
         FIG. 7  is a view illustrating the flow of the checking processing of the image processing apparatus according to the first embodiment; and 
         FIG. 8  is a view illustrating a configuration of the reading section of an image processing apparatus according to a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Modes for Carrying Out the Invention 
     Embodiments according to the present invention will be described below referring to the accompanying drawings. The same or equivalent components throughout the drawings are designated by the same reference numerals, and overlapping descriptions are omitted. 
     First Embodiment 
       FIG. 1  is a view illustrating a general outline of a configuration of an image processing apparatus  100  according to a first embodiment of the present invention. The image processing apparatus  100  is a multifunctional machine having a copying function and a scanning function, for example. As shown in  FIG. 1 , the image processing apparatus  100  includes a control section  101 , a storage section  102 , an operation section  103 , a display section  104  and a reading section  105 . 
     The control section  101  is formed of an MPU, for example, and operates according to programs stored in the storage section  102 . 
     The storage section  102  is formed of an information recording medium, such as a ROM, a RAM or a hard disk, for storing programs executed by the control section  101 . Furthermore, the storage section  102  also serves as the working memory of the control section  101 . The programs may be provided, for example, by downloading via a network, or by various computer-readable recording media, such as a CD-ROM or a DVD-ROM. 
     The operation section  103  is formed of an interface, such as a plurality of buttons or a touch panel displayed on the display section  104  described later. According to an instruction operation performed by the user, the operation section  103  outputs the content of the instruction operation to the control section  101 . 
     The display section  104  is formed of, for example, a liquid crystal display or an organic EL display, and displays information according to instructions from the control section  101 . 
     The reading section  105  scans the surface of a medium moved by a conveying section  201  described later using image sensors, thereby reading the image of the medium. Specifically speaking, the reading section  105  reads a pattern appearing on the surface of the medium, such as a pattern formed by fibers constituting the medium. The reading section  105  may also be configured so as to read a pattern formed by, for example, minute cracks or the particles of materials on the surface of the medium, as disclosed in Japanese Patent Application Laid-open Publication No. 2005-10581. Furthermore, this embodiment is described assuming that paper, such as manuscript paper, is used as a medium and that a paper fingerprint serving as a pattern appearing on the surface of the medium is read. However, the medium is not limited to such paper, but a plastic substrate, for example, may also be used as a medium. 
     Specifically speaking, the reading section  105  includes the conveying section  201 , a contact glass  202 , first to third mirrors  203  to  205 , a lens  206 , and image sensors  207  and  208  as shown in  FIG. 2 . 
     The conveying section  201  has lead-in rollers  209 , a conveying roller  210  and discharge rollers  211 . The lead-in rollers  209  move a medium  212  (for example, manuscript paper) one sheet at a time to the conveying roller  210  according to an instruction input to the operation section  103  by the user, for example. The conveying roller  210  moves the medium  212  onto the contact glass  202 . 
     At this time, the surface of the medium  212  is read by the image sensors  207  and  208 . Specifically speaking, the reflected light from the medium  212  is imaged on the image sensors  207  and  208  via the first to third mirrors  203  to  205  and the lens  206 , whereby the image sensors  207  and  208  obtain the image of the surface of the medium  212 . It is not needless to say that the reflected light is the reflected light of the light irradiated from a light source (not shown) to the medium  212  and reflected by the surface of the medium  212 . In addition, the image sensors  207  and  208  are each formed of, for example, a CCD (charge-coupled device) linear sensor in which light-sensitive cells (pixels), such as photodiodes, are arranged linearly. 
     More specifically, in this embodiment, the first image sensor  208  reads the surface of the medium  212  at a first reading line  214 , and the second image sensor  207  reads the surface of the medium  212  at a second reading line  215 . The first reading line  214  is set on the upstream side in the conveying direction and the second reading line  215  is set on the downstream side in the conveying direction as shown in  FIG. 2 . In addition, the first and second reading lines  214  and  215  are disposed linearly, for example, in a direction (scanning direction) orthogonal to the conveying direction  213  of the medium  212  on the contact glass  202 . 
     The configuration of the reading section  105  shown in  FIG. 2  is just an example and not limited to this configuration. Furthermore, the image processing apparatus  100  may be configured to additionally have a network interface (not shown) so as to be communicatable with other computers, facsimile machines, image processing apparatuses, etc. through networks. 
       FIG. 3  is a view functionally illustrating a configuration of the control section of the image processing apparatus. As shown in  FIG. 3 , the control section  101  of the image processing apparatus  100  has an image obtaining section  301 , a noise judgment section  302 , a noise position information obtaining section  303 , an image generation section  304 , a paper fingerprint information obtaining section  305 , a paper fingerprint position information obtaining section  306 , a judgment section  307 , a paper fingerprint information registration section  308 , a registered paper fingerprint information obtaining section  309 , and a checking section  310 . 
     The image obtaining section  301  obtains an image read by the reading section  105 . Specifically speaking, the image obtaining section  301  obtains the images of the surface of the medium  212  read using the first image sensor  208  and the second image sensor  207 , for example. 
     On the basis of the images, the noise judgment section  302  judges whether noise is present. Specifically speaking, the following is described by taking a case in which paper powder has attached to part of the second reading line  215 , for example. At this time, streaky noise, not present on the medium  212 , appears in the sub-scanning direction on the image output from the second image sensor  207 . On the other hand, since no paper powder is present on the first reading line  214 , the first image sensor  208  reads the surface of the medium  212  normally, and the above-mentioned streaky noise does not appear. The noise judgment section  302  judges whether the image read by the first image sensor  208  is coincident with the image read by the second image sensor  207 , thereby judging whether noise due to paper powder, etc. is present. 
     The noise position information obtaining section  303  obtains the position information of the noise. Specifically speaking, for example, streaky noise  403  appears in the obtained image as shown in  FIG. 4 .  FIG. 4  is a view showing an example of a general outline of the processing executed by the paper fingerprint information registration section  308 . The left side of  FIG. 4  shows a case in which the noise  403  is included in the image of a read manuscript, and the right side of  FIG. 4  shows an area  401  that is registered by the paper fingerprint information registration section  308  described later and an area  402  that is not registered. In addition, the right side of  FIG. 4  is a partly magnified view of the left side of  FIG. 4 . 
     The image generation section  304  generates an image from which the noise is eliminated. This is described specifically, for example, by taking the above-mentioned example. Since the noise  403  is present in the image output from the second image sensor  207 , the pixel values of pixels having the noise  403  are replaced with the pixel values of pixels having no noise and corresponding to the pixels output from the first image sensor  208 . 
     Furthermore, the image generation section  304  may have other configurations, such as a configuration in which noise is eliminated by smoothing the obtained image or a configuration in which pixels having noise are replaced with the pixels adjacent thereto, provided that noise can be eliminated. 
     The paper fingerprint information obtaining section  305  obtains paper fingerprint information from the image output from the image generation section  304 . Specifically speaking, for example, the paper fingerprint information is obtained from predetermined areas on one or more sheets of the medium  212 . The paper fingerprint information is, for example, an image of a pattern formed by fibers constituting the medium  212  (paper). Furthermore, the predetermined area may be the entire area of the medium  212  as shown in  FIG. 4  or may be one or more areas including the end sections of the medium  212 . Moreover, the area may be set on the basis of the noise position information in a noise eliminated image. Moreover, this will be described below more specifically by taking the example shown in  FIG. 4 . 
     The paper fingerprint position information obtaining section  306  obtains the position information of the obtained paper fingerprint information. Specifically speaking, as shown in  FIG. 4 , a plurality of areas  401  and a plurality of areas  402  are set in the image, and the paper fingerprint information obtaining section  305  obtains the paper fingerprint information of the plurality of areas  401  and the plurality of areas  402 . The areas  401  and  402  each correspond to a minimum area for obtaining the paper fingerprint information, for example. In addition, the position information of the paper fingerprint information corresponds to the position information regarding the plurality of areas  401  and the plurality of areas  402 . In other words, the areas  401  and  402  from which the paper fingerprint information is obtained have predetermined widths in the main scanning direction and the sub-scanning direction of the medium  212 , for example, as shown in  FIG. 4 . In other words, for example, in the case that a point in a manuscript is used as the origin and that the conveying direction is defined as a y-axis and the direction orthogonal to the conveying direction is defined as an x-axis, a preset range represented by x and y coordinates is used as the position information of the paper fingerprint information. 
     In the above-mentioned configuration, the areas  401  and  402  are respectively set at predetermined intervals in the main scanning direction (the direction orthogonal to the conveying direction) and the sub-scanning direction (the conveying direction) of the medium  212 . However, it may also be possible to use a configuration in which the areas  401  are provided continuously in the main scanning direction and the sub-scanning direction of the medium  212 . 
     The judgment section  307  judges whether the position information of the obtained paper fingerprint information is different from the position information obtained by the noise position information obtaining section  303 . Specifically speaking, for example, in the case that the noise  403  is not included in the area  401  (registered area) as shown in  FIG. 4 , the judgment section  307  judges that the position information of the paper fingerprint information is different from the noise position information. 
     In the case that the judgment section  307  judges that the position information of the paper fingerprint information is different from the noise position information, the paper fingerprint information registration section  308  registers the paper fingerprint information together with the position information of the paper fingerprint information. Specifically speaking, for example, the paper fingerprint information registration section  308  instructs the storage section  102  to store the paper fingerprint information together with the position information of the paper fingerprint information. It may also be possible to use a configuration in which the paper fingerprint information and its position information are stored in the external database or the like (not shown) of the image processing apparatus  100  through a network. On the other hand, in the case that the judgment section  307  judges that the position information of the paper fingerprint information is not different from the noise position information, for example, in the case that the area  402  (unregistered area) overlaps with the noise  403  as shown in  FIG. 4 , the paper fingerprint information and its position information are not registered (stored). 
     The processing of the judgment section  307  and the processing of the paper fingerprint information registration section  308  are repeated until all the areas  401  included in the image are judged. 
     The registered paper fingerprint information obtaining section  309  obtains the paper fingerprint information and its position information stored in the storage section  102  or other storage media, such as the external database of the image processing apparatus  100 . At this time, for example, the user inputs a file name, etc. through the operation section  103 , whereby the registered paper fingerprint information obtaining section  309  obtains the paper fingerprint information and its position information corresponding to the file name. 
     The checking section  310  obtains the paper fingerprint information (checking paper fingerprint information) regarding the medium  212  to be checked and its position information from the paper fingerprint information registration section  308  and also obtains the registered paper fingerprint information (registered paper fingerprint information) corresponding to the medium  212  to be checked and its position information from the registered paper fingerprint information obtaining section  309 . Then, the checking section checks the checking paper fingerprint information against the registered paper fingerprint information with respect to the corresponding position information. 
     Specifically speaking, the originality of the medium  212  is verified depending on whether the correlation value of the registered paper fingerprint information and the checking paper fingerprint information is a preset reference value or larger, as described in Japanese Patent No. 4103826, for example. However, since the details of the processing are known, the detailed descriptions thereof are omitted. 
     The checking section  310 , for example, displays the result of the checking on the display section  104 . For example, in the case that the medium  212  to be checked is determined to be original as the result of the matching, “ORIGINAL” is displayed, and in the case that the medium  212  to be checked is determined to be unoriginal, “UNORIGINAL” is displayed. The messages displayed are not limited to these, but predetermined symbols, such as ∘ and x, may also be displayed. 
       FIG. 5  is a view illustrating the flow of the registration processing of the image processing apparatus according to this embodiment. First, the image obtaining section  301  obtains an image read by the reading section  105  (at S 101 ) as shown in  FIG. 5 . 
     The noise judgment section  302  judges whether noise is present in the image (at S 102 ). In the case that the noise judgment section  302  judges that noise is present, the image generation section  304  generates a noise eliminated image in which noise is eliminated (at S 103 ). The noise position information obtaining section  303  obtains the position information of the noise (at S 104 ). On the other hand, in the case that the noise judgment section  302  judges that noise is not present, the processing advances to S 105 . 
     The paper fingerprint information obtaining section  305  obtains the paper fingerprint information from the noise eliminated image or from the image obtained at S 101  (at S 105 ). The paper fingerprint position information obtaining section  306  obtains the position information of the obtained paper fingerprint information (at S 106 ). 
     The judgment section  307  judges whether the position information of the paper fingerprint information is different from the position information of the noise (at S 107 ). In the case that the judgment section  307  judges that the position information of the paper fingerprint information is different from the position information of the noise, the paper fingerprint information is registered (at S 108 ). Specifically speaking, the position information of the paper fingerprint information is registered together with the paper fingerprint information. On the other hand, in the case that the judgment section  307  judges that the position information of the paper fingerprint information is not different from the position information of the noise, the processing advances to S 109 . 
     The judgment section  307  judges whether any unregistered area is present in the obtained image (at S 109 ). In the case that the judgment section  307  judges that an unregistered area is present, the processing returns to S 107 , and the judgment section  307  judges whether the position information of the next paper fingerprint information is different from the position information of the noise. On the other hand, in the case that the judgment section  307  judges that no unregistered area is present, the processing ends (at S 110 ). 
     The flow of the registration processing described above is not limited to that described above but may be modified variously. The configuration described in the above-mentioned embodiment may be replaced with a configuration substantially identical thereto, or with a configuration having the same working effect as that thereof, or with a configuration capable of achieving the same purpose as that thereof. 
     For example, the paper fingerprint information obtaining section  305  may be configured so as to obtain the paper fingerprint information from areas in the noise eliminated image, not containing the noise, and the paper fingerprint information registration section  308  may be configured so as to register the paper fingerprint information. At the time of the registration, the position information of the paper fingerprint information may also be registered. 
     Furthermore, for example, in the case that the noise  403  overlaps with the areas  402  as shown in  FIG. 6 , the paper fingerprint information registration section  308  may be configured so that the registration is carried out while the areas  402  are moved so as not to overlap with the noise  403 ; in other words, the section may be configured so that the registration is carried out while the overlapping is avoided. In  FIG. 6 , the moved areas are represented by the areas  401  (registered areas). In this case, depending on the result of the judgment of the judgment section  307 , the paper fingerprint information obtaining section  305  sets the areas  401  which are not overlapping with the noise  403  and from which the paper fingerprint information is obtained, and then obtains the paper fingerprint information from the areas  401 . Then, the paper fingerprint information registration section  308  registers the paper fingerprint information together with its position information. 
       FIG. 6  is a view showing another example of a general outline of the processing executed by the paper fingerprint information registration section. The left side of  FIG. 6  shows a case in which the noise  403  is included in the image of a read manuscript, and the right side of  FIG. 6  shows the area  401  that is registered by the paper fingerprint information registration section  308  described later and the area  402  that is not registered. In addition, the right side of  FIG. 6  is a partly magnified view of the left side of  FIG. 6   
     Next, the checking processing for verifying the originality of the medium  212  will be described below.  FIG. 7  is a view illustrating the flow of the checking processing of the image processing apparatus according to this embodiment. 
     As shown in  FIG. 7 , first, processing similar to the processing from S 101  to S 109  shown in  FIG. 5  is carried out for the medium  212  to be checked (at S 201 ). 
     Next, the registered paper fingerprint information obtaining section  309  obtains the registered paper fingerprint information and its position information corresponding to the medium  212  to be checked (at S 202 ). The paper fingerprint information and its position information are stored, for example, in the storage section  102  as described above. 
     The checking section  310  checks the registered paper fingerprint information against the paper fingerprint information to be checked on the basis of the corresponding position information (at S 203 ). The result of the checking is displayed on the display section  104  (at S 204 ). 
     The flow of the checking processing described above is not limited to that described above but may be modified variously. The configuration described in the above-mentioned embodiment may be replaced with a configuration substantially identical thereto, or with a configuration having the same working effect as that thereof, or with a configuration capable of achieving the same purpose as that thereof. 
     For example, although the configuration in which the paper fingerprint information is checked on the basis of one piece of position information corresponding thereto is described above, it may be possible to use a configuration in which respective pieces of the paper fingerprint information are checked on the basis of the corresponding plural pieces of the position information. In this case, for example, a configuration may also be used in which the result of the checking is displayed on the basis of the statistics of the result of the checking of the plural pieces of the paper fingerprint information to be checked. Specifically speaking, for example, in the case that, among a plurality of results of the checking of the plural pieces of paper fingerprint information, the results of the checking, the number of which is a preset value or larger, indicate that the medium  212  is original, the medium is judged to be original. 
     Furthermore, although the configuration in which the processing from S 101  to S 109  shown in  FIG. 5  is carried out is used in the flow of the checking processing described above, the present invention is not limited to use this configuration. It may be possible to use a configuration in which paper fingerprint information is obtained from the medium to be checked in areas having the position information of the registered paper fingerprint information, and the paper fingerprint information is checked against the registered paper fingerprint information. 
     The present invention is not limited to the above-mentioned embodiment described above but may be modified variously. For example, the configuration described in the above-mentioned embodiment can be replaced with a configuration substantially identical thereto, or with a configuration having the same working effect as that thereof, or with a configuration capable of achieving the same purpose as that thereof. 
     Second Embodiment 
     Next, a second embodiment according to the present invention will be described below. The above-mentioned first embodiment in which the reading section  105  has two image sensors, i.e., the image sensors  207  and  208 , is different from the second embodiment in which the reading section  105  has only one image sensor, i.e., the image sensor  208 . Descriptions of the components similar to those of the first embodiment are omitted in the following descriptions. 
       FIG. 8  is a view illustrating a configuration of the reading section  105  according to this embodiment. The reading section  105  includes the conveying section  201 , the contact glass  202 , the first to third mirrors  203  to  205 , the lens  206 , and the image sensor  208  as shown in  FIG. 8 . 
     As in the first embodiment, the conveying section  201  has the lead-in rollers  209 , the conveying roller  210  and the discharge rollers  211 . The lead-in rollers  209  move the medium  212  one sheet at a time to the conveying roller  210  according to an instruction input to the operation section  103  by the user, for example. The conveying roller  210  moves the medium  212  onto the contact glass  202  while changing the conveying direction  213  of the medium  212 . 
     At this time, the surface of the medium  212  is read by the image sensor  208 . Specifically speaking, the reflected light from the medium  212  is imaged on the image sensor  208  via the first to third mirrors  203  to  205  and the lens  206 , whereby the image sensor  208  obtains the image of the surface of the medium  212 . 
     In other words, in this embodiment, one image sensor, i.e., the image sensor  208 , reads the image of the medium  212  at one reading line. In other words, unlike the above-mentioned first embodiment in which two image sensors, i.e., the image sensors  207  and  208 , and two reading lines are provided, one image sensor, i.e., the image sensor  208 , reads the surface of the medium  212  that is conveyed on the reading line  214 . 
     On the basis of the image from the image sensor  208 , the noise judgment section  302  judges whether noise is present. In other words, the noise judgment section  302  judges whether the image read by the image sensor satisfies predetermined conditions. For example, the judgment section  307  judges that noise is present when such a streak as shown in  FIG. 4  appears in the image read by the image sensor  208 . Specifically speaking, the judgment section  307  specifies pixels having a pixel value (density value) not less than a predetermined reference value among the pixels of the image read by the image sensor and judges that noise is present in the case that the pixels are arranged continuously in the conveying direction. In this case, the arrangement of the pixels may be indistinguishable, in some cases, from a black line (an arrangement of black pixels in the image of the surface of the medium, identifiable as noise) included in the image, for example. However, since plural pieces of paper fingerprint information are registered as described above in the present invention, it may be possible to use a configuration in which the black line is judged as noise and the paper fingerprint information of the areas including the black line is not registered. 
     The present invention is not limited to the above-mentioned first and second embodiments described above but may be modified variously. For example, the configurations described in the above-mentioned embodiments can be replaced with a configuration substantially identical thereto, or with a configuration having the same working effect as that thereof, or with a configuration capable of achieving the same purpose as that thereof. 
     The foregoing description of the embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments are chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.