JP4977085B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus that automatically corrects read image information.

  An image reading apparatus having a function of reading an image recorded on a document and outputting it as a read image, represented by a copying machine, a scanner, a FAX, and the like, is caused by dust attached to a document reading position on a platen glass. There is one that corrects a read image by detecting a streak generated in the read image and replacing the image information of the read image in which the streak is generated with other image information (see, for example, Patent Document 1).

JP 2005-1117090 A

  However, in the image reading apparatus described in Patent Document 1, streaks generated in the read image are caused by dust or the like attached to the document reading position on the platen glass, or caused by ruled lines of the original image. It is difficult to determine whether the image is a streak, and the correction accuracy of the read image in which streaks occur is low.

  The present invention has been made in view of the above circumstances, and the problem of the present invention is that streaks generated in a read image are caused by dust or the like attached to a document reading position on a platen glass, or By determining whether or not it is caused by the ruled line of the original image and comparing and correcting and updating information on the streak pattern generated in the read image every time the original is read (hereinafter referred to as streak information), It is an object of the present invention to provide an image reading apparatus capable of improving the correction accuracy of a read image in which streaks occur and reducing the occurrence of streaks in the read image.

  Further, it is determined whether the streaks generated in the read image are caused by dust or the like adhering to the original reading position on the platen glass or the original image, and the original is read. Provided is an image reading method capable of improving the correction accuracy of a read image in which a streak is generated by comparing, correcting, and updating streak information generated in the read image each time and reducing the occurrence of a streak in the read image. This is the issue.

In order to solve the above-described problems, an image reading apparatus according to the present invention includes an image reading unit that reads recorded information recorded on a medium as image information, and an image information storage that stores image information read by the image reading unit. A feature pattern information extraction unit that extracts, as feature pattern information, a feature pattern different from the recorded information from the image information stored in the image information storage unit, and stores the feature pattern information extracted by the feature pattern information extraction unit The feature pattern information storage unit, the feature pattern information based on the image information of the first page read by the image reading unit, and the feature pattern information based on the image information read after the first page are read from the feature pattern information storage unit. And a feature pattern information comparison unit that corrects the feature pattern information by comparing, and feature pattern information And a characteristic pattern removing unit for removing the characteristic pattern information from the image information based on the corrected characteristic pattern information by 較部, characteristic pattern information some unprintable area of the image information read by the image reading unit To the printable area continuously or intermittently.

  The image reading apparatus of the present invention is characterized in that a feature pattern that is different from recorded information recorded on a medium is extracted as feature pattern information, so-called streak information, from image information that is read by an image reading unit and stored in an image information storage unit. A pattern information extraction unit is provided. Since the feature pattern information extracted by the feature pattern information extraction unit is image information that does not exist in the recording information recorded on the medium, the feature pattern generated in the read image is caused by dust or the like attached to the document reading position. It is possible to determine whether the information is recorded or is due to recorded information on the medium. The image reading apparatus of the present invention compares the feature pattern information based on the image information of the first page read by the image reading unit with the feature pattern information based on the image information read from the first page onward. A feature pattern information comparison unit that corrects the feature pattern information is provided. Therefore, the feature pattern information is corrected every time the document is read by the image reading unit, so that more accurate feature pattern information can be acquired. Furthermore, since the feature pattern removal unit removes the feature pattern information from the image information based on the high-precision feature pattern information acquired by the feature pattern information comparison unit, it is possible to reduce the occurrence of the feature pattern for the read image. .

The image reading method of the present invention includes an image reading step for reading recorded information recorded on a medium as image information, and an image information storage step for storing the image information read in the image reading step in an image information storage unit. , A feature pattern information extraction step for extracting a feature pattern different from the recorded information from the image information stored in the image information storage unit as feature pattern information, and feature pattern information extracted in the feature pattern information extraction step Feature pattern information storing step, feature pattern information based on the image information of the first page read in the image reading step, and feature pattern information based on the image information read after the first page Feature pattern that corrects feature pattern information by reading from the storage and comparing Comprising an information comparing step and the feature pattern removing step of removing the characteristic pattern information from the image information based on the feature pattern information corrected by the feature pattern information comparing step, wherein the pattern information is image information read by the image reading step Is partly present continuously or intermittently from the unprintable area to the printable area.

  The image reading method of the present invention is a feature pattern information extracting step of extracting, as feature pattern information, a feature pattern different from the recorded information recorded on the medium from the image information read in the image reading step and stored in the image information storage unit. Is provided. Since the feature pattern information extracted by the feature pattern information extraction process is image information that does not exist in the recording information recorded on the medium, the feature pattern generated in the read image is caused by dust or the like attached to the document reading position. It is possible to determine whether the information is generated or is caused by recorded information on the medium. The image reading method of the present invention compares the feature pattern information based on the image information of the first page read in the image reading step with the feature pattern information based on the image information read from the first page. A feature pattern information comparison step for correcting the feature pattern information is provided. Therefore, the feature pattern information is corrected every time the document is read in the image reading process, so that more accurate feature pattern information can be acquired. Furthermore, in the feature pattern information removal step, the feature pattern is removed from the image information based on the highly accurate feature pattern information acquired by the feature pattern information comparison step, thereby reducing the occurrence of the feature pattern for the read image. it can.

  According to the image reading apparatus of the present invention, the streaks generated in the read image are caused by dust or the like attached to the original reading position on the platen glass, or are caused by ruled lines of the original image. By comparing and correcting the streak information generated in the scanned image every time the document is scanned, the correction accuracy of the scanned image in which the streaks are generated is improved and the occurrence of streaks in the scanned image is reduced. It is possible to provide an image reading apparatus capable of performing the above.

  Further, according to the image reading method of the present invention, streaks generated in the read image are caused by dust or the like adhering to the document reading position on the platen glass, or caused by ruled lines of the original image. The streak information generated in the scanned image is compared, corrected, and updated each time the document is scanned, thereby improving the correction accuracy of the scanned image where the streak is generated and reducing the occurrence of streaks in the scanned image. It is possible to provide an image reading method that can be used.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably.

[First embodiment]
FIG. 1 is a schematic external view of an image processing apparatus including a scanner 100 as an image reading apparatus according to the first embodiment of the present invention. The image processing apparatus includes a scanner 100 and a printer 300 as an image forming apparatus that forms an image on a recording medium such as paper based on image information input from the scanner 100. Therefore, the image processing apparatus can output the recorded information on the document read by the scanner 100 to the outside by printing on the recording medium. In the description of this embodiment, an image processing apparatus including the scanner 100 as an image reading apparatus will be described.

  FIG. 2 is a perspective view of the appearance of the scanner 100. As shown in FIG. 2, the scanner 100 separates and conveys sheets 101 on which images as recording information are formed one by one, and reads an image on the sheet 10, an ADF (Auto Document Feeder) unit 102, and an ADF unit 102. Are provided on the upper surface of the document cover unit 104 and the document cover unit 104 that supports the ADF unit 102. An LCD (Liquid Crystal Display) 105 to be displayed and an FB (Flat Bed) unit 106 to be described later are provided. First, the ADF unit 102 will be described, and then the FB unit 106 will be described.

  As shown in FIG. 3, the ADF unit 102 includes at least a pickup roller 107 that separates and conveys the sheets 101 placed on the sheet tray 103 one by one, an ADF reading unit 108 that reads an image on the sheet 101, and an ADF. A discharge roller 109 that discharges the sheet 101 on which an image is read by the reading unit 108 and a sheet position sensor 110 that detects the front end position of the sheet 101 are provided.

  The pickup roller 107 is composed of at least a pair of rollers, and is provided on the upstream side of the sheet conveyance path e. The pick-up roller 107 is rotated by power supplied from a drive motor (not shown) to convey the paper 101 into the ADF unit 102.

  The ADF reading unit 108 is provided in the middle of the paper conveyance path e, and includes a light source (not shown) that emits light to at least the paper 101 and a CCD (Charge Coupled Device) that converts the received light into a digital signal. ) An image sensor and light guiding means for condensing the light reflected by the paper 101 and guiding the light to the CCD image sensor. The light source is not particularly limited. For example, a cold cathode tube such as a molybdenum electrode having a long life and low power consumption can be used. The CCD image sensor is one of image pickup devices, and outputs image information by converting the brightness of received light into a digital signal. Processing of image information output by the CCD image sensor will be described in detail later. For example, a mirror and / or a lens can be used as the light guiding unit, and the light guiding unit is disposed at a position where the light reflected by the paper 101 is imaged on the CCD image sensor.

  The discharge roller 109 includes at least a pair of rollers, and is provided on the downstream side of the paper transport path e. The discharge roller 109 is rotated by power supplied from a drive motor (not shown), and discharges the paper 101 on which an image has been read by the ADF reading unit 108 to the outside of the scanner 100.

  The paper position sensor 110 is an optical sensor that detects the front end position of the paper 101 and is provided near the end of the paper transport path e. The paper position sensor 110 is not particularly limited, and for example, a light transmission type or light reflection type photo interrupter can be used.

  An operation of reading an image on the sheet 101 by the ADF unit 102 having such a configuration will be described. First, the scanner 100 that has received an instruction to start reading an image on the paper 101 gives a drive instruction to a drive motor (not shown). Upon receiving the drive instruction, the drive motor rotates the pickup roller 107. The pickup roller 107 conveys the paper 101 into the ADF unit 102 by rotating. At the timing when the sheet 101 passes the image reading position of the ADF reading unit 108, the ADF reading unit 108 reads an image on the sheet 101. The ADF reading unit 108 outputs image information, and the output image information is stored in a storage unit described later. A discharge roller 109 discharges the paper 101 on which an image has been read out of the scanner 100. At this time, when the paper position sensor 110 detects the paper 101, the scanner 100 gives a drive instruction to a drive motor (not shown) in accordance with the timing when the paper 101 is discharged to the outside of the scanner 100. Upon receiving the drive instruction, the drive motor rotates the pickup roller 107. The pickup roller 107 rotates to convey the next sheet 101 into the ADF unit 102, and the image reading operation is executed again. This image reading operation is repeatedly executed until the paper 101 placed on the paper tray 103 runs out.

  Next, the FB unit 106 will be described. As shown in FIG. 4, the FB unit 106 includes a document table 111 on which the sheet 101 is placed, a sheet pressing member 112 that presses the sheet 101 placed on the document table 111, and a sub-direction in the direction of the arrow in the figure. An FB reading unit 113 that reads an image on the paper 101 placed on the document table 111 while reciprocating in the scanning direction, and an FB transport unit that transports the FB reading unit 113 in the sub-scanning direction indicated by an arrow in the figure. 114.

  The document table 111 is a light-transmissive transparent member that forms a document placement surface on which the paper 101 is placed. The document table 111 is not particularly limited, but, for example, rectangular plate glass or the like can be used.

  The sheet pressing member 112 is a rectangular plate-shaped member having substantially the same area as the document table 111 and is provided on the back surface of the document cover unit 104. The sheet pressing member 112 includes a light reflective white sheet on the contact surface with the sheet 101. The white sheet has a size that covers the entire reading range in which the reading unit 113 for the FB executes a reading operation, and is attached to the sheet pressing member 112 with, for example, a double-sided adhesive tape.

  The FB reading unit 113 has a length substantially the same as the length of the document table 111 in the short direction, and reads an image on the sheet 101 from below the document table 111. Since the FB reading unit 113 has substantially the same configuration as the ADF reading unit 108, description thereof is omitted here.

  The FB transport unit 114 at least drives the transport belt by stretching and rotating the endless transport belt that transports the FB reading unit 113 in the sub-scanning direction indicated by the arrow in the figure. A pair of drive rollers. The FB transport unit 114 transports the FB read unit 113 in response to a reading start instruction.

  An operation of reading an image on the sheet 101 by the FB unit 106 having such a configuration will be described. First, when the user sets the paper 101 on the platen 111 and inputs an image reading start instruction, the scanner 100 gives a driving instruction to the FB transport unit 114. Receiving the drive instruction, the FB transport unit 114 transports the FB read unit 113 from the initial position to a predetermined read start position. When the FB reading unit 113 reaches a predetermined reading start position, the FB reading unit 113 starts reading an image on the paper 101. The FB reading unit 113 reads an image on the sheet 101 while moving in the sub-scanning direction. The FB reading unit 113 outputs image information, and the output image information is stored in a storage unit described later. When the FB reading unit 113 reaches a predetermined reading stop position, the FB transport unit 114 reversely rotates the drive roller, transports the FB read unit 113 to the initial position, and the reading operation by the FB unit 106 ends.

  As described above, the image on the sheet 101 can be acquired as image information by the reading operation using the ADF unit 102 or the FB unit 106 provided in the scanner 100.

  Next, the internal configuration of the scanner 100 will be described. FIG. 5 is a block configuration diagram of the scanner 100. The scanner 100 includes a reading unit 120 as an image reading unit including the ADF unit 102 or the FB unit 106 described above, a storage unit 1 as an image information storage unit that stores image information output from the reading unit 120, and a storage. An initial reading determination unit 121 that determines whether the image information stored in the unit 1 is image information of the first page, and a feature pattern information extraction unit that extracts streak information from the image information stored in the storage unit 1 Extracted by the feature pattern extraction unit 122, the storage unit 2 as a feature pattern information storage unit that stores streak information related to the image information of the first page extracted by the feature pattern extraction unit 122, and the feature pattern extraction unit 122 A storage unit 3 as a feature pattern information storage unit for storing streak information relating to image information on the second and subsequent pages, a storage unit 2 and a storage unit 3 The feature pattern comparison unit 123 as a feature pattern information comparison unit that corrects the stripe information and stores the corrected stripe information in the storage unit 2 again, and the feature pattern comparison unit 123. And a feature pattern removing unit 124 that removes or corrects the line information from all the image information stored in the storage unit 1 based on the high-precision line information acquired by the above.

  As described above, the reading unit 120 includes the ADF unit 102 and the FB unit 106, and outputs an image on the sheet 101 as image information. Here, image information output from the ADF reading unit 108 or the FB reading unit 113 will be described with reference to FIGS. 6, 7, and 8.

  Reflected light of light emitted from a light source (not shown) to the paper 101 is guided to a CCD image sensor by a light guide means (not shown). The CCD image sensor converts the brightness of received light into a digital signal. Specifically, the CCD image sensor uses the light and dark information of the received light as pixel numbers in the main scanning direction (X) and the sub-scanning direction (Y). Is converted into arrangement information and output as image information. In other words, the light brightness / darkness information is the pixel number in FIG. [0] to [a-1] and [b + 1] to [H] are non-printable areas in the main scanning (X) direction, image No. [a] to [b] are printable areas in the main scanning (X) direction. [0] to [c-1] and [d + 1] to [V] are designated as non-printable areas in the sub-scanning (Y) direction. When [c] to [d] are printable areas in the sub-scanning (Y) direction, they are expressed in association with position information P (X, Y) of arbitrary pixels. That is, when light / dark information of light exists in a pixel located at an arbitrary P (X, Y), it is expressed as P (X, Y) = 1, and the pixel located at an arbitrary P (X, Y) When there is no light contrast information, it is expressed as P (X, Y) = 0.

  In general, when dust or the like adheres to a document reading position, black stripes as shown in FIG. 7 occur in the scanned image in the sub-scanning direction. Normally, the ruled lines for the original image are not drawn in the non-printable area, and for example, as shown in FIG. 7, black stripes continuously occur from the non-printable area to the printable area ( In the case 1) or when it occurs intermittently (case 2), it can be determined that the black streak is caused by dust or the like attached to the document reading position. That is, as shown in FIG. 8, if there is a pixel (P (X, Y) = 1) having light / dark information in the non-printable area in the image information output from the reading unit 120, it occurs in the read image. It can be determined that black stripes are caused by dust or the like attached to the document reading position.

  The storage unit 1 stores pixel numbers as image information output from the reading unit 120. This is a storage area for storing the arrangement information. The storage unit 1 may be mounted as a volatile memory, a non-volatile rewritable storage device such as a flash memory, or a magnetic medium such as a hard disk. Good.

  The initial reading determination unit 121 determines whether the image information output from the reading unit 120 is the image information of the first page. Here, when the output image information is the image information of the first page, the initial reading determination unit 121 notifies the feature pattern extraction unit 122 to that effect, and as feature pattern information from the image information. Gives instructions for extracting streak information. On the other hand, when the output image information is not the image information of the first page, the initial reading determination unit 121 notifies the feature pattern extraction unit 122 to that effect and also instructs to extract the stripe information from the image information. give.

  The feature pattern extraction unit 122 extracts line information from the image information stored in the storage unit 1 based on an instruction from the initial reading determination unit 121, and the extracted line information is derived from the image information of the first page. In this case, the extracted streak information is stored in the storage unit 2. In addition, when the extracted streak information is derived from the image information of the second page and thereafter, the extracted streak information is stored in the storage unit 3. Here, the line information extracted from the storage unit 1 by the feature pattern extraction unit 122 and stored in the storage unit 2 or the storage unit 3 will be described in detail with reference to FIG.

  For example, the reading unit 120 reads the paper 101 on which the character image “A” is formed in the printable area, and the pixel No. corresponding to the pixel image diagram shown in FIG. Is output as image information. Further, it is assumed that the image information output by the reading unit 120 is stored in the storage unit 1. First, the feature pattern extraction unit 122 receives the pixel numbers stored in the storage unit 1 based on instructions from the initial reading determination unit 121. Read the placement information. Next, the feature pattern extraction unit 122 extracts the position information P (X, Y) of the pixel having light brightness / darkness information, and extends in the sub-scanning direction of the extracted pixel, that is, from the non-printable area to the printable area. To set a streak information flag indicating that a streak exists. Specifically, the feature pattern extraction unit 122 sets the pixel numbers of the areas (1), (2), and (3) in FIG. Extract the placement information. When the extracted pixel position information is stored in the storage unit 2, the feature pattern extraction unit 122 indicates that the light pixel information is present in the extracted pixel position information P (X, Y). 1 is set and stored as a streak pattern P2 (X, Y). On the other hand, when the extracted pixel position information is stored in the storage unit 3, the feature pattern extraction unit 122 indicates that the light pixel information is present in the extracted pixel position information P (X, Y). Is set to 1 and stored as a streak pattern P3 (X, Y). Also, the feature pattern extraction unit 122 sets Flag [X] as a streak information flag to 1 or 0. When Flag [X] is stored in the storage unit 2, the feature pattern extraction unit 122 stores the streak information flag as Flag2 [X]. When Flag [X] is stored in the storage unit 3, the feature pattern extraction unit 122 stores the streak information flag as Flag3 [X].

  The storage unit 2 and the storage unit 3 store information such as the streak pattern and the streak information flag as streak information. The storage unit 2 stores streak information derived from the image information of the first page extracted by the feature pattern extraction unit 122. The storage unit 3 also stores streak information derived from the image information of the second and subsequent pages extracted by the feature pattern extraction unit 122. The storage unit 2 and the storage unit 3 may be mounted as a volatile memory, a non-volatile rewritable storage device such as a flash memory, or a magnetic medium such as a hard disk. May be.

  The feature pattern comparison unit 123 compares and corrects the line information stored in each of the storage unit 2 and the storage unit 3 and stores the corrected line information in the storage unit 2 again.

  10, FIG. 11, and FIG. 12 are examples of the storage format of the streak information extracted by the feature pattern extraction unit 122 and stored in the storage unit 2 or the storage unit 3 in the pixel image diagram shown in FIG. It is a figure explaining an example of the memory | storage form of the stripe information which the comparison part 123 compared and correct | amended based on the stripe information memorize | stored in the memory | storage part 2 and the memory | storage part 3, respectively. 10 is a streak information table stored in the storage unit 2, FIG. 11 is a streak information table stored in the storage unit 3, and FIG. 12 is a streak information stored in the storage unit 2 after being compared and corrected by the feature pattern comparison unit 123. An information update information table is shown. Each streak information table includes a main scanning pixel No. indicating the X position of the pixel located at Flag [X], P (X, Y). ([X]), sub-scanning pixel No. indicating the Y position of the pixel located at P (X, Y). ([Y]), with streak patterns.

  In the streak information table stored in the storage unit 2, the areas (1) ′, (2) ′, and (3) ′ in FIG. 10 surrounded by dotted lines are (1), (2), ( This is line information corresponding to the area 3). Further, in the streak information table stored in the storage unit 3 in FIG. 11, the areas (1) ″, (2) ″, (3) ″ surrounded by dotted lines are similarly ( Line information corresponding to the areas 1), (2), and (3). As described above, the line information derived from the image information of the first page is first stored in the storage unit 2, and the line information derived from the image information of the second page and thereafter is stored in the storage unit 3. Here, for example, the streak pattern does not change between the region (1) ′ and the region (1) ″. Therefore, it can be seen that the streaks generated in this region are not caused by the ruled lines of the original image but are caused by dust or the like. However, since the area (1) 'and the area (1) "are located in the non-printable area, the values of Flag2 [X] and Flag3 [X] are both 0. Further, in both the region (2) ′ and the region (2) ″, and in the region (3) ′ and the region (3) ″, the streak pattern is changed. In the region (2) ′, four pixels have light brightness information, whereas in the region (2) ″, only three pixels have light brightness information. Since the streak corresponding to one pixel is generated only in the first page, it can be determined that the streak is caused by a ruled line in the original image. Similarly, in the area (3) ′, 8 pixels have light brightness information, whereas in the area (3) ″, only 6 pixels have light brightness information. Since the streaks corresponding to the two pixels are generated only in the first page, it can be determined that the streaks are caused by ruled lines in the original image. As described above, the feature pattern comparison unit 123 compares and corrects the streak information stored in the storage unit 2 and the storage unit 3 respectively, so that the region (1) ′ ″ in the update information table in FIG. , (2) ′ ″, (3) ′ ″ are generated as streak information and stored in the storage unit 2 again. The comparison and correction by the feature pattern comparison unit 123 are repeatedly executed for the number of sheets 101 read by the reading unit 120. Therefore, the scanner 100 can always acquire highly accurate streak information.

  The feature pattern removal unit 124 removes or corrects the stripe information from all the image information stored in the storage unit 1 based on the high-precision stripe information acquired by the feature pattern comparison unit 123. In general, the actual image portion of the original image and the streak pattern often intersect. Here, the intersection pattern between the actual image portion and the streak pattern relating to the original image will be described first, and the process executed by the feature pattern removal unit 124 based on the intersection pattern will be described.

  FIG. 13 is a diagram illustrating an example of an intersection pattern between a real image portion and a streak pattern related to an original image. As shown in FIG. 13, the intersection patterns can be roughly classified into a case where the actual image portion intersects obliquely and a case where the intersection intersects vertically. Here, A4 and B3 in FIG. 13 indicate points where the actual image portion and the streak pattern intersect.

  FIG. 14 is a diagram for explaining the intersection pattern between the actual image portion and the streak pattern in the original image in more detail. Here, the pixel Z indicates a point where the actual image portion and the streak pattern intersect. As shown in FIG. 13, the intersection pattern between the actual image portion and the streak pattern is the case where the actual image portion and the streak pattern intersect diagonally and when the actual image portion and the streak pattern intersect perpendicularly. Further, there are cases where the actual image portion and the streak pattern are in contact with each other as in patterns 1 to 14 in FIG. Here, A4 and B3, which are points where the real image portion and the streak pattern shown in FIG. 13 intersect, correspond to the patterns 15 to 21 shown in FIG. B2 and B4 shown in FIG. 13 correspond to the pattern 22 and the pattern 23 shown in FIG. The feature pattern removal unit 124 executes processing based on the following rules when removing or correcting the stripe information of the stripe pattern indicating such an intersection pattern from the image information on the actual image portion.

(When the intersection pattern is from pattern 1 to pattern 14)
When the real image portion is adjacent to only one side of the streak pattern, the RGB value of the pixel Z is replaced with an image of (0, 0, 0). The unit of the pixel Z is actually a small value as compared with the entire real image, and even if the RGB value is replaced with (0, 0, 0) in the adjacent portion of the real image portion, the effect of appearance is small.
(When the intersection pattern is from pattern 15 to pattern 21)
When the actual image portion and the streak pattern intersect, replacing the RGB value with an image of (0, 0, 0) stands out as a white streak. In this case, the RGB value of the pixel Z is replaced with an average value image of the RGB values of all adjacent pixels. Thereby, the pixel Z can be made inconspicuous by replacing the color of the stripe generated on the actual image portion with a value close to that of the surrounding actual image.
(When the intersection pattern is pattern 22 and pattern 23)
In the case of this pattern, the RGB values are replaced with an image of (0, 0, 0), similarly to the processing in pattern 1 to pattern 14.
(When the intersection pattern is other than pattern 1 to pattern 23)
In the case of this pattern, a plurality of real image portions are adjacent to each other around the pixel Z, and the RGB values of the pixels Z are averaged of the RGB values of all the adjacent pixels, as in the processing from the intersection pattern 15 to the pattern 21. Replace with a value image. Thereby, the pixel Z can be made inconspicuous by replacing the color of the stripe generated on the actual image portion with a value close to that of the surrounding actual image.

  As described above, the feature pattern removal unit 124 executes processing based on the above rules, thereby making the point pixel Z where the actual image portion and the streak pattern intersect become inconspicuous.

  FIG. 15 is a pixel image diagram of the image information from which the streak information has been removed by the feature pattern removal unit 124 based on the streak information that has been improved by the feature pattern comparison unit 123. In the pixel image diagram described with reference to FIG. 9, streak information exists in the areas (1), (2), and (3) as described above. As described with reference to FIGS. 10, 11, and 12, the line information relating to this area is corrected with high accuracy by the feature pattern comparison unit 123 and stored in the storage unit 2 as an update information table. Based on the update information table stored in the storage unit 2, the feature pattern removal unit 124 removes or corrects the stripe information from the image information related to the original image. That is, as shown in FIG. 15, the feature pattern removal unit 124 stores (1) ′ ″, (2) ′ stored in the update information table from the image information relating to the original image stored in the storage unit 1. The image information relating to the original image is corrected by removing or correcting the streak information corresponding to the region of '', (3) ′ ''. Note that the area (D3) of the image information after removal of the streak information is determined as a ruled line for the original image by the feature pattern comparison unit 123, and thus remains as it is without being removed or corrected by the feature pattern removal unit 124.

  The image information from which the streak information has been removed by the feature pattern removal unit 124 is output to the printer 300. The printer 300 to which the image information is input translates the image information into a printer description language and prints it on a recording medium. The printer 300 is not particularly limited. For example, an electrophotographic printer or the like can be used.

  The initial reading determination unit 121, the feature pattern extraction unit 122, the feature pattern comparison unit 123, and the feature pattern removal unit 124 described so far are mounted on the scanner 100 as programs. These programs may be stored in a volatile memory of the scanner 100, a nonvolatile memory such as a ROM (Read Only Memory), or a nonvolatile rewritable storage device such as a flash memory. It may be mounted or may be mounted as a magnetic medium such as a hard disk. Although not shown, the scanner 100 is further provided with an operation panel as a user interface. A CPU (Central Processing Unit) that controls the operation of the scanner 100 is mounted, and a primary storage device such as a memory as a working area of the CPU is mounted.

  The ADF unit 102 according to the present embodiment is configured such that the ADF reading unit 108 is mounted, but the present invention is not limited to this. For example, an image information reading window composed of, for example, a light transmissive member is provided in the middle of the paper conveyance path e of the ADF unit 102, and the FB reading unit 113 is aligned with the timing at which the paper 101 passes through the image information reading window. Thus, the recording information on the paper 101 may be read.

  Next, processing executed by the scanner 100 having such a configuration will be described. First, the overall processing executed by the scanner 100 will be described, and then the processing executed by the feature pattern extraction unit 122, the processing executed by the feature pattern comparison unit 123, and the processing executed by the feature pattern removal unit 124 will be described using a flowchart. I will explain.

  First, the overall processing executed by the scanner 100 will be described using the flowchart of FIG. In step S301, when the recording information on the sheet 101 is read as image information by the reading unit 120, the reading unit 120 stores the image information in the storage unit 1 (step S302). When the image information is stored in the storage unit 1, the scanner 100 instructs the initial reading determination unit 121 to determine whether the image information stored in the storage unit 1 is the first page image information. Upon receiving the determination instruction, the initial reading determination unit 121 determines whether or not the image information stored in the storage unit 1 is the image information of the first page (step S303). When the image information stored in the storage unit 1 is the image information of the first page (step S303 Yes), the initial reading determination unit 121 notifies the feature pattern extraction unit 122 to that effect and extracts the line information. Give instructions to do so. The feature pattern extraction unit 122 that has received the streak information extraction instruction extracts the streak information from the image information stored in the storage unit 1 (step S304) and stores the extracted streak information in the storage unit 2 (step S304). S305).

  On the other hand, when the initial reading determination unit 121 determines that the image information stored in the storage unit 1 is not the image information of the first page (No in step S303), the initial reading determination unit 121 notifies the feature pattern extraction unit. 122 is notified, and an instruction is given to extract streak information. Receiving the streak information extraction instruction, the feature pattern extraction unit 122 extracts the streak information from the image information stored in the storage unit 1 (step S306), and stores the extracted streak information in the storage unit 3 (step S306). S307).

  When the line information is stored in the storage unit 3, the scanner 100 compares and corrects the line information stored in the storage unit 2 and the line information stored in the storage unit 3 with respect to the feature pattern comparison unit 123. At the same time, the storage unit 2 is instructed to store the corrected streak information (step S308).

  When the extraction of the streak information in step S304 and step S306, which will be described later, and the correction of the streak information in step S308 are completed, and reading of all the image information by the reading unit 120 is completed (step S309 Yes), the scanner 100 stores in the storage unit 2. All the streak patterns related to the unprintable area in the stored streak information are unconditionally set to 1 (step S310). Next, the scanner 100 instructs the feature pattern removal unit 124 to remove or correct the stripe information from the image information. The feature pattern removing unit 124 that has received the instruction corrects the image information by removing or correcting the streak information stored in the storage unit 2 from all the image information stored in the storage unit 1 (step S311). .

  When the streak information is removed or corrected from the image information stored in the storage unit 1, the scanner 100 displays that fact on the LCD 105 (step S312). Further, the scanner 100 outputs image information from which the streak information has been removed or corrected to the printer 300 (step S313). The printer 300 to which the image information from which the streak information has been removed or input is input prints the image information on a recording medium, and thus the series of processes ends.

  Next, processing executed by the feature pattern extraction unit 122 in step S304 and step S306 in FIG. 16 will be described using the flowchart in FIG. In addition, since the process in step S304 and step S306 is substantially the same process, FIG. 17 demonstrates the process concerning step S304. In the process of step S306, the P2 (X, Y) part in the processes of steps S405, S406, S408, and S409 in FIG. 17 is set to P3 (X, Y), and Flag2 [X] in the process of step S410 is set. Each is replaced with Flag3 [X].

  In step S303 in FIG. 16, the feature pattern extraction unit 122 that has received the streak information extraction instruction from the initial reading determination unit 121 receives the pixel No. in the main scanning direction. A is set in X of the (step S400). Next, the feature pattern extraction unit 122 confirms whether or not X is a range indicating a printable area. If X is a range indicating a printable area (Yes in step S401), the sub-scanning direction pixel No. 0 is set to Y of (step S402). Next, the feature pattern extraction unit 122 confirms whether Y is a range indicating a printable area (step S403). Here, when Y is not in the range indicating the printable area (No in step S403), the feature pattern extraction unit 122 confirms whether or not P (X, Y) has light contrast information (step S407). . When P (X, Y) has light contrast information (Yes in step S407), the feature pattern extraction unit 122 sets 1 to P2 (X, Y) (step S408) and sets Flag2 [X] to 1 (Step S410). On the other hand, when P (X, Y) does not have light contrast information (No in step S407), the feature pattern extraction unit 122 sets 0 to P2 (X, Y) (step S409).

  In step S403, if Y is the range indicated in the printable area (step S403 Yes), the feature pattern extraction unit 122 confirms whether P (X, Y) has light brightness information (step S404). ). If P (X, Y) has light contrast information (Yes in step S404), the feature pattern extraction unit 122 sets 1 to P2 (X, Y). On the other hand, if P (X, Y) does not have light contrast information (No in step S404), the feature pattern extraction unit 122 sets P2 (X, Y) to 0 (step S406).

  Next, the feature pattern extraction unit 122 adds 1 to Y (step S411), and Y is sub-scanning direction pixel No. The process from step S403 to step S411 is repeated until the final pixel position V is reached, that is, until the light brightness / darkness information of all pixels in the sub-scanning direction with respect to the pixel position X in the specific main scanning direction is confirmed ( Step S412). Y is the sub-scanning direction pixel No. When V reaches the final pixel position V (Yes in step S412), the feature pattern extraction unit 122 adds 1 to X (step S413), and repeats the processing from step S401 to step S412.

  Next, the processing executed by the feature pattern comparison unit 123 in step S308 in FIG. 16 will be described using the flowchart in FIG. The scanner 100 compares and corrects the streak information stored in the storage unit 2 and the streak information stored in the storage unit 3, and receives an instruction to store the corrected streak information in the storage unit 2. The pattern comparison unit 123 is a main scanning direction pixel No. A is set in X of step S420. Next, the feature pattern comparison unit 123 checks whether or not X is a range indicating a printable area. If X is a range indicating a printable area (Yes in step S421), Flag2 [X] and Flag3 [ It is confirmed whether or not 1 is set to X] (step S422). Here, when 1 is set in Flag2 [X] and Flag3 [X], the feature pattern comparison unit 123 displays the pixel No. in the sub-scanning direction. 0 of Y is set (step S423).

  Next, the feature pattern comparison unit 123 checks whether or not Y is a range indicating a printable area (step S424). Here, when Y is the range indicated in the printable area (Yes in step S424), the feature pattern comparison unit 123 sets 1 to P2 (X, Y) and sets P3 (X, Y). It is confirmed whether or not 0 is set (step S425). When P2 (X, Y) is set to 1 and P3 (X, Y) is set to 0 (Yes in step S425), the feature pattern comparison unit 123 sets P2 (X, Y). It is set to 0 (step S426).

  On the other hand, when Y is not in the range indicating the printable area (No in step S424), the feature pattern comparison unit 123 sets 0 to Flag2 [X] and 1 to Flag3 [X]. It is confirmed whether or not there is (step S427). When 0 is set in Flag2 [X] and 1 is set in Flag3 [X] (Yes in step S427), the feature pattern comparison unit 123 sets 0 in P2 (X, Y). And whether P1 (X, Y) is set to 1 (step S428), P2 (X, Y) is set to 0, and P3 (X, Y) is set. When 1 is set to (Yes in step S428), the feature pattern comparison unit 123 sets P2 (X, Y) to 1 (step S429).

  Next, the feature pattern comparison unit 123 adds 1 to Y (step S430), and Y is the sub-scanning direction pixel No. The process from step S424 to step S430 is repeated until the final pixel position V is reached, that is, until the light brightness / darkness information of all pixels in the sub-scanning direction with respect to the pixel position X in the specific main scanning direction is confirmed ( Step S431). Y is the sub-scanning direction pixel No. When reaching the final pixel position V (Yes in step S431), the feature pattern comparison unit 123 adds 1 to X (step S432), and repeats the processing from step S421 to step S431.

  Next, the processing executed by the feature pattern removal unit 124 in step S311 in FIG. 16 will be described using the flowcharts in FIGS. Upon receiving an instruction from the scanner 100 to remove or correct the stripe information from the image information, the feature pattern removal unit 124 receives the pixel No. in the main scanning direction. A is set in X of the (step S440). Next, the feature pattern removal unit 124 checks whether 1 is set in Flag2 [X] (step S441). Here, when Flag2 [X] is set to 1 (Yes in step S441), the feature pattern removal unit 124 determines whether the sub-scanning direction pixel No. 0 is set in Y of (step S442). Next, the feature pattern removal unit 124 confirms whether Y is in a range indicating a printable area (step S443). If Y is in the range indicated by the printable area (step S443 Yes), the feature pattern removal unit 124 checks whether 1 is set to P2 (X, Y) (step S444). When P2 (X, Y) is set to 1 (Yes in Step S444) and the condition in Step S445 or Step S446 is satisfied, the feature pattern removal unit 124 determines that the pixel Z at the intersection of the actual image portion and the streak pattern Are replaced with an image of (0, 0, 0) (step S450). On the other hand, when any of the conditions of step S447, step S448, and step S449 is satisfied, the RGB value of the pixel Z at the intersection of the actual image portion and the streak pattern is set around the pixel Z that does not exist on the same sub-scan line. The average value of the RGB values of the contacting pixels is replaced (step S451).

  Next, the feature pattern removing unit 124 adds 1 to Y (step S452), and Y is sub-scanning direction pixel No. The processing from step S443 to step S452 is repeated until the pixel position of d reaches d (step S453). When Y reaches the pixel position d (step S453 Yes), the feature pattern removal unit 124 adds 1 to X (step S432), and X is the pixel No. in the main scanning direction. The process from step S441 to step S454 is repeated until b is reached.

  As described above, according to the first embodiment, on the basis of the stripe information on the non-printable area, the stripe generated in the read image is caused by dust or the like attached to the document reading position, or It can be determined whether it is caused by the ruled line of the original image. Further, since the streak information is compared, corrected and updated for each read image information, the correction accuracy of the image in which the streaks are generated can be improved.

[Second Embodiment]
In addition to the configuration of the image processing apparatus according to the first embodiment, the image processing apparatus according to the second embodiment of the present invention replaces the reading unit 120 included in the image processing apparatus according to the first embodiment, and includes a detection unit. A reading unit 220 including a 221 and a conveyance unit 222 is provided.

  FIG. 21 is a block diagram for explaining an internal configuration of a scanner 200 as an image reading apparatus according to the second embodiment of the present invention. Since the internal configuration of the scanner 200 is substantially the same as the internal configuration of the scanner 100 described in the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  The reading unit 220 includes a detection unit 221 that detects a front end portion or a rear end portion of the paper 101 and a transport unit 222 that transports the paper 101 in a direction opposite to the paper transport direction.

  The detection unit 221 is provided at a predetermined position on the paper transport path e, and detects the front end or the rear end of the paper 101. The detection unit 221 is not particularly limited, but the paper position sensor 110 described in the first embodiment may be used, or a light transmission type or light reflection type photo interrupter may be newly installed. Good.

  The transport unit 222 includes a reverse transport member that is provided on the downstream side of the paper transport path e and transports the paper 101 in the direction opposite to the paper transport direction. Although the reverse conveying member is not particularly limited, the pickup roller 107 and the discharge roller 109 described in the first embodiment may be used, for example, a normal sheet by motive power supplied from a drive motor (not shown). You may newly install the roller etc. which rotate in the reverse direction to a conveyance direction.

  Next, processing executed by the scanner 200 having such a configuration will be described.

  FIG. 22 is a flowchart for explaining the overall processing executed by the scanner 200. In step 501, when the recording information on the sheet 101 is read as image information by the reading unit 220, the reading unit 220 stores the image information in the storage unit 1 (step S502). When the image information is stored in the storage unit 1, the scanner 100 instructs the initial reading determination unit 121 to determine whether the image information stored in the storage unit 1 is the first page image information. Upon receiving the determination instruction, the initial reading determination unit 121 determines whether or not the image information stored in the storage unit 1 is the image information of the first page (step S503). When the image information stored in the storage unit 1 is the first page image information (Yes in step S503), the initial reading determination unit 121 has obtained the image information stored in the storage unit 1 by the first reading. Whether it is image information or not is discriminated (step S504). Here, in the case of image information obtained by the first reading (step S504 Yes), the initial reading determination unit 121 notifies the feature pattern extraction unit 122 to that effect and gives an instruction to extract the line information. . Receiving the streak information extraction instruction, the feature pattern extraction unit 122 extracts the streak information from the image information stored in the storage unit 1 (step S505) and stores the extracted streak information in the storage unit 2 (step S505). S506). Next, the scanner 200 gives a drive instruction to a control motor (not shown). The reverse conveyance member included in the conveyance unit 222 starts rotating, and conveys the paper 101 in the direction opposite to the paper conveyance direction. At the timing when the detection unit 221 detects the front edge or the rear edge of the reversely conveyed paper 101, the reading unit 220 starts reading the paper 101 again (step S507).

  On the other hand, when the initial reading determination unit 121 determines that the image information stored in the storage unit 1 is not the image information of the first page (No in step S503), it is not the image information obtained by the first reading. When the determination is made (No in step S504), the initial reading determination unit 121 notifies the feature pattern extraction unit 122 to that effect and gives an instruction to extract the line information. The feature pattern extraction unit 122 that has received the streak information extraction instruction extracts the streak information from the image information stored in the storage unit 1 (step S508), and stores the extracted streak information in the storage unit 3 (step S508). S509).

  When the line information is stored in the storage unit 3, the scanner 200 compares and corrects the line information stored in the storage unit 2 and the line information stored in the storage unit 3 with respect to the feature pattern comparison unit 123. In addition, an instruction is given to store the corrected streak information in the storage unit 2 (step S510).

  When the extraction of the streak information in step S505 and step S508 and the correction of the streak information in step S510 are completed and the reading of all image information by the reading unit 220 is completed (Yes in step S511), the scanner 200 is stored in the storage unit 2. All the streak patterns in the unprintable area in the streak information are unconditionally set to 1 (step S512). Next, the scanner 200 instructs the feature pattern removal unit 124 to remove or correct the stripe information from the image information. Upon receiving the instruction, the feature pattern removal unit 124 corrects the image information by removing or correcting the streak information stored in the storage unit 2 from all the image information stored in the storage unit 1 (step S513). .

  When the streak information is removed or corrected from the image information stored in the storage unit 1, the scanner 200 displays that fact on the LCD 105 (step S514). Further, the scanner 200 outputs the image information from which the streak information has been removed or corrected to the printer 300 (step S515). The printer 300 to which the image information from which the streak information has been removed or inputted is printed, prints the image information on a recording medium, and the series of processes ends.

The processing executed by the feature pattern extraction unit 122 in step S505 and step S508, the processing executed by the feature pattern comparison unit 123 in step S510, and the processing executed by the feature pattern removal unit 124 in step S513 are described in the first embodiment. The processing can be performed in the same manner as described above.

  As described above, according to the second embodiment, in addition to the effects of the first embodiment, an image of the first page can be read twice, so that an original composed of only one page can be read. Can improve the accuracy of streak information. Furthermore, since the streak information of the first page can be taken into account for a document composed of a plurality of pages, the accuracy of the streak information can be further improved.

  In the description of the present embodiment, a printer is provided as an external output unit, but the present invention is not limited to this. For example, an image read by a scanner may be directly transmitted to an information processing apparatus such as a personal computer.

1 is a schematic external view of an image processing apparatus. It is a perspective view of the appearance of a scanner. It is sectional drawing of a scanner. It is a perspective view of the appearance of a scanner. It is a block diagram explaining the internal structure of a scanner. It is a figure explaining image information. It is a figure explaining the stripe which generate | occur | produces in a read image. It is a figure explaining the stripe which generate | occur | produces in a read image. Pixel No. It is a figure explaining the arrangement | positioning information. It is a figure explaining a streak information table. It is a figure explaining a streak information table. It is a figure explaining a streak information table. It is a figure explaining the intersection pattern of a real image part and a stripe pattern. It is a figure explaining the intersection pattern of a real image part and a stripe pattern. It is a pixel image figure of the image information from which stripe information was removed. It is a flowchart explaining the whole process which a scanner performs. It is a flowchart explaining the process which a feature pattern extraction part performs. It is a flowchart explaining the process which a feature pattern comparison part performs. It is a flowchart explaining the process which a feature pattern removal part performs. It is a flowchart explaining the process which a feature pattern removal part performs. It is a block diagram explaining the internal structure of a scanner. It is a flowchart explaining the whole process which a scanner performs.

Explanation of symbols

100 Scanner 101 Paper 102 ADF Unit 103 Paper Tray 104 Document Cover Unit 105 LCD
106 FB Unit 107 Pickup Roller 108 ADF Reading Unit 109 Ejection Roller 110 Paper Position Sensor 111 Document Stand 112 Paper Pressing Member 113 FB Reading Unit 114 FB Transport Unit 120 Reading Unit 121 Initial Reading Discrimination Unit 122 Feature Pattern Extraction Unit 123 Features Pattern comparison unit 124 Feature pattern removal unit 200 Scanner 220 Reading unit 221 Detection unit 222 Conveying unit 300 Printer

Claims (8)

An image reading unit that reads recorded information recorded on the medium as image information;
An image information storage unit for storing the image information read by the image reading unit;
A feature pattern information extraction unit that extracts, as feature pattern information, a feature pattern different from the recorded information from the image information stored in the image information storage unit;
A feature pattern information storage unit for storing the feature pattern information extracted by the feature pattern information extraction unit;
The feature pattern information based on the image information of the first page read by the image reading unit and the feature pattern information based on the image information read after the first page are read from the feature pattern information storage unit and compared. A feature pattern information comparison unit for correcting the feature pattern information,
A feature pattern removal unit that removes the feature pattern information from the image information based on the feature pattern information corrected by the feature pattern information comparison unit ;
The image reading characterized in that the feature pattern information includes a part of the image information read by the image reading unit continuously or intermittently from a non-printable area to a printable area. apparatus.   The image reading apparatus according to claim 1, wherein the feature pattern is a streak pattern. The feature pattern removal unit replaces the RGB value of the intersecting pixel where the pixel indicated by the recording information and the pixel indicated by the feature pattern information intersect with 0 according to the intersecting pattern, or around the intersecting pixel. 3. The image reading apparatus according to claim 1, wherein the image reading device is replaced with an average RGB value of another pixel in contact. The image reading unit includes a reading unit that reads a specific page of the medium a plurality of times, and when image information relating to the specific page read by the image reading unit is image information of the first page, The feature pattern information comparison unit corrects the feature pattern information by comparing feature pattern information based on image information read for the first time and feature pattern information based on image information read again. Item 4. The image reading apparatus according to any one of Items 1 to 3. The reading means detects a front end and a rear end of the medium;
A transport unit for transporting the medium,
When reading the specific page, the detection unit detects the rear end of the medium, so that the conveyance unit reversely conveys the medium, and the front end of the medium reaches the reading position of the image reading unit. 5. The image reading apparatus according to claim 4, wherein when the recording information is read, the recording information on the medium is read again.   6. The image reading apparatus according to claim 1, further comprising notification means for notifying that the removal of the feature pattern information has been executed. An image reading apparatus according to any one of claims 1 to 6,
An image processing apparatus comprising: an image forming apparatus that forms an image on a recording medium based on image information output by the image reading apparatus. An image reading step of reading recorded information recorded on the medium as image information;
An image information storage step of storing the image information read in the image reading step in an image information storage unit;
A feature pattern information extracting step for extracting, as feature pattern information, a feature pattern different from the recorded information from the image information stored in the image information storage unit;
A feature pattern information storage step for storing the feature pattern information extracted in the feature pattern information extraction step in a feature pattern information storage unit;
The feature pattern information based on the image information of the first page read in the image reading step and the feature pattern information based on the image information read after the first page are read from the feature pattern information storage unit and compared. A feature pattern information comparison step for correcting the feature pattern information,
A feature pattern removal step of removing the feature pattern information from the image information based on the feature pattern information corrected in the feature pattern information comparison step ,
The image reading is characterized in that the feature pattern information includes a part or part of the image information read in the image reading process continuously or intermittently from a non-printable area to a printable area. Method.