JP2012015592A - Image processing apparatus - Google Patents

Abstract

A user is notified of a placement state of a document to prompt relocation and obtain an appropriate read image.
An image processing apparatus includes an image reading unit for reading an original, an outline extracting unit for extracting an outline of a document in a read image, and a forefront of the document among the outlines. The fore edge angle detection unit 33 that detects the fore edge angle formed by the first outer shape outline and the second outer shape outline indicating the fore edge is compared with the fore edge angle and the first threshold value, and based on the comparison result. A determination unit 34 that determines whether or not the read image is distorted, and a display unit 35 that displays a document placement guide based on a determination result by the determination unit 34. For this reason, since it is possible to display a message prompting the user to distort the arrangement of the original in the read image and to rearrange the original 21, it is possible to easily obtain a read image with little distortion.
[Selection] Figure 1

Description

  The present invention relates to an image processing apparatus such as a scanner, a copying machine, and a facsimile.

  Conventionally, a technique for correcting image distortion at the time of reading a bound original, for example, by extracting the outline of the outline of the original from the read image data and obtaining the degree of distortion from the information on the outline, Based on this, there is known a technique that corrects distortion of a binding portion by expanding an image.

  A technique relating to distortion correction in such an image processing apparatus is described in, for example, the following Patent Document 1.

JP 2006-87027 A

  However, in the conventional image processing apparatus, when the original is pressed against the mounting table and read, if the strength of pressing between the top and the bottom of the original is different, the image is distorted in the vicinity of the binding portion, and an eight-shaped dark portion is formed. The case that occurs is not considered. Therefore, in such a case, it is difficult to perform an appropriate distortion correction process.

  An image processing apparatus according to the present invention includes a placement table on which a document having a binding portion and a fore edge is placed, reads the document placed on the placement table, and outputs a read image; and the read image A distortion detection unit that detects a distortion state of the original arrangement caused by the binding unit, and a detection result of the distortion detection unit and a first threshold value are compared, and the distortion state exceeds the first threshold value. A determination unit configured to determine that the document arrangement is distorted; and a display unit configured to display a distortion state of the document in the document based on a determination result of the determination unit and to prompt rearrangement.

  According to the image processing apparatus of the present invention, the distortion of the document arrangement is detected, and the document distortion image indicating the document distortion state and a message prompting the user to reposition the document are displayed. Distortion correction processing can be performed.

FIG. 1 is a functional block diagram showing the configuration of the image processing apparatus 10 of FIG. 2 in Embodiment 1 of the present invention. FIG. 2 is a configuration diagram showing an outline of the image processing apparatus 10 according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating an example of distortion of the document 21F read by the image reading unit 31 of FIG. FIG. 4 is a diagram showing the read image 30 when the fore edge angle detection unit 33 of FIG. 1 calculates the fore edge angle θ and when the determination unit 34 determines the spreading direction of the figure eight shape. FIG. 5 is a diagram illustrating an example of a message displayed by the display unit 35 in FIG. 1 when the document 21F is spread on the back side A1. FIG. 6 is a diagram showing an example of a message displayed by the display unit 35 in FIG. 1 when the document 21F spreads to the near side A2. FIG. 7 is a flowchart showing the operation of the image processing apparatus 10 of FIG. 1 in Embodiment 1 of the present invention. FIG. 8 is a subroutine showing the fore edge angle calculation process in step S3 of FIG. FIG. 9 is a subroutine showing the figure-of-eight shape determination process in step S5 of FIG. FIG. 10 is a functional block diagram showing the configuration of the image processing apparatus 10A according to the second embodiment of the present invention. FIG. 11 is a diagram when the binding portion extraction unit 52 in FIG. 10 extracts the region outline 43a of the low luminance region 24F. FIG. 12 is a diagram illustrating the read image 20F when the determination unit 54 of FIG. 10 determines the spreading direction of the figure eight shape. FIG. 13 is a flowchart showing the operation of the image processing apparatus 10A of FIG. 10 according to the second embodiment of the present invention. FIG. 14 is a subroutine showing the figure-shaped determination process in step S36 of FIG.

  Modes for carrying out the present invention will become apparent from the following description of the preferred embodiments when read in light of the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Configuration of Example 1)
2A and 2B are configuration diagrams schematically showing the image processing apparatus 10 according to the first embodiment of the present invention. FIG. 2A is an overall perspective view, and FIG. FIG.

  The image processing apparatus 10 is, for example, a scanner, and is an apparatus that optically reads the original 21 of the bookbinding 20 and outputs a read image including an electric signal.

  The bookbinding 20 has a binding portion 22 in which a plurality of originals 21 are bound, and a first fore edge 23 a and a second fore edge 23 b in left and right portions facing the binding portion 22. The upper part of the bookbinding 20 is called the ceiling 25 and the lower part is called the ground 26.

  Such an image processing apparatus 10 for reading a document 21 includes an image sensor 11 for obtaining a read image of the document 21, a mounting table 12 on which a bookbinding book 20 to be read is mounted, and a cursor displayed on the display panel 15. An operation button 13 for capturing a user operation such as movement or selection of an icon displayed on the display panel 15 as an electrical signal, a start button 14 for capturing an operation for starting and stopping the reading operation of the document 21 as an electrical signal, and an operation Based on a signal input from the button 13, the display panel 15 displays the state of the image processing apparatus 10 and various information, and a cover 16 that can be opened and closed to cover the upper surface of the mounting table 12.

  For example, the image sensor 11 is configured to perform main scanning by arranging photoelectric conversion elements such as a charge coupled device (CCD) in a line. The photoelectric conversion element is configured so that light emitted from the lower direction of the mounting table 12 receives reflected light reflected by the document 21 and converts it into an electrical signal. The image sensor 11 has a function of reading the document 21 by moving in the sub-scanning direction Y perpendicular to the main scanning direction X by a stepping motor or the like.

  The mounting table 12 has a document mounting portion made of a transparent plastic plate or glass plate for mounting the document 21, and a frame portion that supports the document mounting portion. In the first embodiment, the part of the mounting table 12 far from the user's operation is referred to as the back side A1, and the part close to the user's operation is referred to as the near side A2. The cover 16 covers the mounting table 12 in order to block external light from the outside when the image sensor 11 reads the document 21.

  FIG. 1 is a functional block diagram showing the image processing apparatus 10 of FIG. 2 in Embodiment 1 of the present invention.

  The image processing apparatus 10 includes a distortion detection unit 30, an image reading unit 31, a determination unit 34, a display unit 35, and a control unit 36 that controls the entire apparatus. Although not shown, the control unit 36 is stored in a read only memory (hereinafter referred to as “ROM”) for storing various programs, a random access memory (RAM) for storing processing target data such as a read image, and the ROM. It is configured by a processor or the like that reads a program and executes various processes.

  The image reading unit 31 includes the image sensor 11, the mounting table 12, and an analog-digital conversion circuit and various correction circuits (not shown). When the user presses the start button 14, the image reading device 10 is configured to read the document 21 by the image sensor 11 and generate a read image (not shown) from the acquired electrical signal.

  The distortion detection unit 30 includes a contour extraction unit 32 and a fore edge angle detection unit 33. The contour extracting unit 32 has a function of extracting an outer contour line indicating the outer shape of the document 21 by detecting an edge in the read image. The fore edge angle detection unit 33 includes a first outer shape outline 23aF indicating the first fore edge 23a and a second outer shape outline 23bF indicating the second fore edge 23b among the outer shape outlines indicating the outer shape of the document 21. And has a function of obtaining a fore edge angle θ which is an angle formed by.

  The determination unit 34 compares the fore edge angle θ formed by the first outer contour line 23aF indicating the first fore edge 23a and the second outer contour line 23bF indicating the second fore edge 23b with the first threshold value TH1. When the fore edge angle θ is larger than the first threshold value TH1, it is determined that the image has an eight-shaped shape, and when the fore edge angle θ is smaller than the first threshold value TH1, the image is determined to be normal. Have.

  The display unit 35 includes the display panel 15 and a drive circuit (not shown). The display unit 35 has a function of displaying a document distortion image showing a state in which the document 21 is spread in an eight-character shape and a message for prompting the rearrangement of the document 21 according to the determination result of the determination unit 34. .

  FIG. 3 is a diagram illustrating an example of distortion of the document 21F read by the image reading unit 31 in FIG.

  In FIG. 3, the read image when the user places the bookbinding 20 on the placement table 12 and presses the back of the bookbinding 20 on the back side A1 of the placement table 12 more strongly than the front side A2. The state of 20F is shown.

  In the read image 20F, the original 21 is in the original 21F in the read image 20F, the binding portion 22 is in the binding portion 22F in the read image 20F, and the fore edge 23a and the fore edge 23b are the outlines 23aF in the read image 20F. The top 25 and the ground 26 correspond to the outline 25b and the ground 26F in the read image 20F, respectively.

  In FIG. 3, the binding portion 22F of the document 21F is parallel to the main scanning direction X of the image sensor 11, the top 25F of the document 21F is the back side A1, and the ground 26F is the front side A2. Show. An outer contour line 23aF and an outer contour line 23bF formed on the left and right sides of the document 21F are open to the back side A1, and a low luminance region 24F is formed from the middle of the binding portion 22F to the front side A2.

  FIG. 4 is a diagram showing the read image 20F when the fore edge angle detection unit 33 in FIG. 1 calculates the fore edge angle θ and when the determination unit 34 determines the direction of the figure-shaped spread.

  Outer outlines 23aF and 23bF are formed on the left and right sides of the document 21F, and the outer outline 23aF and the outer outline 23bF form a fore edge angle θ. The outer contour line 23aF has end points L and J, and the outer contour line 23bF has end points M and K. The first distance D1 between the end point L and the end point M on the back side A1 is smaller than the second distance D2 between the end point J and the end point K on the near side A2, and the document 21F is in the near side A2 direction. It shows that it spreads in the shape of figure eight.

  The read image 20F has a coordinate system, and the lower left of the read image 20F is the origin O. The abscissa axis Z1 is right from the origin O, and the ordinate axis Z2 is upward from the origin O.

  FIG. 5 is a diagram illustrating an example of a message displayed by the display unit 35 in FIG. 1 when the document 21F is spread on the back side A1.

  When reading the original 21, when the read image 20F of the original 21 is spread and read on the back side A1, an original distortion image indicating the distortion state of the arrangement of the original 21F is displayed on the left side of the display panel 15 by the display unit 35. , The message “It spreads in the shape of an eight on the back side. Please press the back on the near side.” Is displayed.

  FIG. 6 is a diagram illustrating an example of a message displayed by the display unit 35 in FIG. 1 when the document 21F is spread on the near side A2.

  In reading the original 21, when the read image 20F of the original 21 is read spreading toward the front side A2, a distortion image of the original showing the distortion state of the arrangement of the original 21F is displayed on the left side of the display panel 15 by the display unit 35. , The message “It spreads in the shape of an eight on the near side. Please press the back on the back.” Is displayed.

(Operation of Example 1)
FIG. 7 is a flowchart showing the operation of the image processing apparatus 10 of FIG. 1 according to the first embodiment of the present invention.

  The user places the document 21 on the mounting table 12 and presses the start button 14 to start the processing. In step S <b> 1, the image reading unit 31 reads the document 21 placed on the placing table 12 with the image sensor 11 and obtains a read image 20 </ b> F. In step S2, the contour extraction unit 32 performs edge detection processing on the read image 20F read in step S1, and detects the outline contour line of the document 21F in the read image 20F.

  In the edge detection processing, for example, as described in Japanese Patent Application Laid-Open No. 2010-87826, for each line extending in the horizontal direction in the read image 20F, the difference in pixel value between pixels adjacent in the left-right direction is calculated for each pixel. To calculate. Among the pixels having the calculated difference value equal to or greater than a predetermined threshold value TH4, the coordinates of the leftmost pixel and the coordinates of the rightmost pixel are detected as edge coordinates that are coordinates indicating the edge portion. Note that the edge detection process may be performed by other methods.

  In step S3, the fore edge angle calculation unit 33 uses the two linear portions of the outer outline of the document 21F detected in step S2 as the first outer outline 23aF indicating the fore 23a and the second for indicating the fore 23b. Is extracted as the outer contour line 23bF, and the acute angle formed by the first outer contour line 23aF and the second outer contour line 23bF is calculated as the edge angle θ.

  In step S4, the determination unit 34 compares the fore edge angle θ calculated in step S3 with the first threshold value TH1. When the fore edge angle θ calculated in step S3 is larger than the first threshold value TH1 (YES), the process proceeds to step S5, and when it is equal to or smaller than the first threshold value TH1 (NO), it is determined as normal and this process is terminated.

  In step S5, the side on which the figure eight shape is widened in the read image 20F is obtained. In step S6, when the back side A1 of the document 21F is widened, the display unit 35 displays a document distortion image indicating the distortion state of the arrangement of the document 21F on the left side of the display panel 15, as shown in FIG. A message for prompting the user to press the front side A2 of the bookbinding 20 is displayed on the right side, and the process is terminated. Similarly, when the front side A2 of the bookbinding 20 is widened, as shown in FIG. 5, a document distortion image showing the distortion state of the arrangement of the document 21F and a message for urging to press the back side A1 of the bookbinding 20 are displayed. indicate.

  FIG. 8 is a subroutine showing the fore edge angle calculation process in step S3 of FIG.

  This subroutine shows a process in which the fore edge detection unit 33 calculates an acute fore edge angle θ formed by the first and second outer contour lines 23aF and 23bF indicating the fore edges 23a and 23b of the document 21F.

  In step S3 of FIG. 7, this subroutine is called. In step S11, a straight line portion is detected from the outline contour line of the document 21F obtained in step S2 of FIG. In step S12, two of the outline contour lines of the straight line portion obtained in step S11, which have a small angle with the main scanning direction X of the image sensor 11, are used as the first outline outline 23aF indicating the fore edge 23a and the fore edge. A second outer contour line 23bF indicating 23b is assumed. In step S13, the fore edge angle detection unit 33 performs an angle calculation process on the first and second outer contour lines 23aF and 23bF extracted in step S12.

In the angle calculation process, for example, as described in Japanese Patent Application Laid-Open No. 2010-021937, both end coordinates (x ₁ , y ₁ ) and (x ₂ , y ₂ ) of the outer contour line 23aF are detected, Based on this, an inclination angle γ1 with respect to the horizontal direction is calculated. Specifically, the inclination angle γ1 is calculated by calculating tan γ1 = (y ₂ −y ₁ ) / (x ₂ −x ₁ ). For the outer contour line 23bF, the angle θ formed by the outer contour line 23aF and the outer contour line 23bF is obtained by calculating the inclination angle γ2 by the same method and obtaining the difference between γ1 and γ2. Note that the angle calculation process may be performed by other methods.

  In this way, the fore edge angle θ formed by the first and second outer contour lines 23aF and 23bF is calculated, the present process is terminated, and the process returns to step S4 in FIG.

  FIG. 9 is a subroutine showing the figure-of-eight shape determination process in step S5 of FIG.

  This subroutine shows a process in which the determination unit 34 determines the spreading side in the figure eight shape formed by the first and second outer contour lines 23aF and 23bF indicating the fore edges 23a and 23b.

  In step S5 of FIG. 7, this subroutine is called. In step S21, the determination unit 34 obtains the coordinates of the end points J, K, L, and M of the outer outlines 23aF and 23bF, respectively. In step S22, the coordinate of the ordinate axis Z2 between the end points L and J of the outer contour line 23aF where the coordinate value of the ordinate axis Z2 is larger, for example, the end point L and the end points M and K of the outer contour line 23bF. A first distance D1 with the larger value, for example, the end point M is obtained.

  Similarly, of the end points L and J of the outer contour line 23aF, the coordinate value of the ordinate axis Z2 is smaller on the side where the coordinate value of the ordinate axis Z2 is smaller, for example, the end point J and the end points M and K of the outer contour line 23bF. A second distance D2 with the smaller side, for example, the end point K is obtained.

  In step S23, the magnitudes of the first distance D1 and the second distance D2 obtained in step S22 are compared. If the first distance D1 is large, the document 21F has an octagonal shape on the back side A1. When the second distance D2 is large, it is determined that the document 21F has spread in an octagonal shape on the front side A2, and the process returns to step S6 in FIG.

(Effect of Example 1)
According to the first embodiment, there are the following effects (1) to (3).

  (1) When the read image 20F obtained by reading the document 21 has an eight-shaped distortion, the printed portion included in the low luminance region 24F may be visually unreadable. In an apparatus for creating a duplicate based on visual observation, such as a copying machine, the copying operation is performed again.

  On the other hand, according to the first embodiment, the original distortion image indicating the distortion state of the original 21F and the message prompting the rearrangement of the bookbinding 20 are displayed, so that a visually readable duplicate can be obtained. it can.

  (2) When the distortion correction process is performed on the read image 20F, the distortion correction process cannot be executed if the brightness is low enough that the print portion included in the low luminance area 24F cannot be corrected.

  On the other hand, according to the first embodiment, the original distortion image indicating the distortion state of the original 21F and a message prompting the rearrangement of the bookbinding 20 are displayed. A read image 20F with less image quality can be obtained. For this reason, the distortion correction process can be executed.

  (3) When the distortion correction process is performed on the read image 20F, the accuracy of the distortion correction process decreases even if the print portion included in the low luminance area 24F can be corrected to a certain degree of brightness, and the distortion correction process is performed. Will take time. In such a case, according to the first embodiment, the rearrangement of the document 21 is appropriately performed, so that the accuracy of the distortion correction processing can be improved and the processing speed of the distortion correction processing can be increased.

(Configuration of Example 2)
FIG. 10 is a functional block diagram showing an image processing apparatus 10A according to the second embodiment of the present invention. Elements common to those in FIG. 1 showing the first embodiment are denoted by common reference numerals.

  The configuration of the image processing apparatus 10A in the second embodiment is substantially the same as the configuration of the image processing apparatus 10 in FIG. The image processing apparatus 10A according to the second embodiment includes the image reading unit 31, the display unit 35, and the control unit 36 that are the same as those in the first embodiment, a distortion detection unit 50 that is different from the first embodiment, and a determination unit 54. is doing. The distortion detection unit 50 includes a binding unit extraction unit 52 and a binding unit angle calculation unit 53.

  The binding portion extraction unit 52 has a function of extracting the binding portion 22F of the document 21F from the read image 20F and outputting the coordinate value of the pixel that is the binding portion 22F. As a method of obtaining the binding portion 22F, for example, as described in the first embodiment, the first and second outer contour lines 23aF and 23bF indicating the fore edges 23a and 23b are extracted and the two outer contour lines 23aF are extracted. , 23bF, a method of using a binding line 22F as a straight line equidistant from the center of the scanned image 20F to obtain two region outlines 43a and 43b of a low luminance region 24F and a normal luminance region. There are a method in which a straight line that is equidistant from the two region outlines 43a and 43b is used as the binding unit 22F, a method in which the straight line connecting the low luminance points by searching the read image 20F is used as the binding unit 22F, and the like.

  The binding portion angle calculation unit 53 obtains a region outline 43a that divides the low luminance region 24F, which is a region where the luminance around the binding portion 22F is low, and a region where the luminance is normal outside thereof, and the region outline It has a function of obtaining a binding portion angle φ formed by 43a and the binding portion 22F.

  The determination unit 54 has a function of determining whether the region shape of the low luminance region 24F is an eight-letter shape based on the binding portion angle φ formed by the region outline 43a and the binding portion 22F, and outputting the determination result. Have.

  FIG. 11 is an explanatory diagram when the binding portion extraction unit 52 in FIG. 10 extracts the region outline 43a of the low luminance region 24F.

  FIG. 11 shows the left half image of the read image 20F, and the left page of the document 21F is displayed. The binding portion 22F has division points 41 (= 41-1, 41-2,..., 41-5) divided by a predetermined number. The vicinity of the binding portion 22F is a low luminance region 24F. From each division point 41 in the direction perpendicular to the binding portion 22F and to the left, the region outline point 42 (= 42-1, 42-2,...) That is the point where the luminance of the pixel exceeds a predetermined threshold TH2. , 42-5) are plotted, and a region outline 43a of the low luminance region 24F is formed so as to substantially connect the plurality of region contour points 42.

  FIG. 12 is a diagram illustrating the read image 20F when the determination unit 54 of FIG. 10 determines the spreading direction of the figure eight shape.

  In FIG. 12, the document 21 </ b> F spreads in an eight-character shape in the direction of the front side A <b> 2. The document 21F is divided into two by a binding portion 22F, and outer contour lines 23aF and 23bF are formed on both sides. Near the binding portion 22F, a low luminance region 24F having a substantially isosceles triangle shape with the top 25F as a base is formed.

  The hypotenuses on both sides of the substantially isosceles triangle formed by the low luminance region 24F are region outlines 43a and 43b that divide the low luminance region 24F and the high luminance portion outside thereof. For example, the left region outline 43a and the binding portion 22F form an angle α on the back side A1 and an angle β on the near side A2. In this figure, the angle α of the back side A1 = the binding portion angle φ.

(Operation of Example 2)
FIG. 13 is a flowchart showing the operation of the image processing apparatus 10A in FIG. 10 according to the second embodiment of the present invention. Elements common to those in FIG. 7 showing the first embodiment are denoted by common reference numerals. .

  In step S <b> 1, the image reading unit 31 reads the document 21 placed on the placing table 12 as in the first embodiment. In step S32, the binding portion extraction unit 52 detects a line segment that separates two facing pages from the read image 20F read in step S1, and uses this as a binding portion 22F.

  The detection method of the binding portion 22F is, for example, as described in the first embodiment, extracting the first and second outer contour lines 23aF and 23bF indicating the fore edges 23a and 23b and extracting the two outer contour lines 23aF, A method in which a straight line that is equidistant from 23bF is used as the binding portion 22F, the vicinity of the center of the read image 20F is searched, and two region outlines 43a and 43b that divide the low luminance region 24F and the normal luminance region are obtained. There are a method in which a straight line equidistant from the two region outlines 43a and 43b is used as the binding unit 22F, a method in which the straight line connecting the low luminance points by searching the read image 20F is used as the binding unit 22F, and the like.

  In step S33, the binding portion angle calculation unit 53 divides the binding portion 22F detected in step S32 into a predetermined number, as shown in FIG. The brightness of each pixel is sequentially measured in the direction perpendicular to 22F and to the left, and compared with a predetermined threshold value TH2. When the luminance of the pixel is lower than the predetermined threshold TH2, it is determined that the pixel is in the low luminance region 24F, and the luminance of the adjacent left pixel is compared with the predetermined threshold TH2.

  When the luminance of the comparison target pixel exceeds a predetermined threshold value TH2, it is determined that the pixel is the region contour point 42 (= 42-1, 42-2,..., 42-5), and the coordinates thereof Find the value. A straight line is obtained using the least square method with the coordinate values of the plurality of region contour points 42 as measurement data.

  In step S34, the obtained straight line is set as a region outline 43a on the left side of the low luminance region 24F, and an acute angle is obtained from angles formed by the region outline 43a and the binding portion 22F, and is set as a binding portion angle φ.

  In step S35, the determination unit 54 compares the acute binding portion angle φ calculated in step S34 with the second threshold value TH3. When the binding portion angle φ is larger than the second threshold value TH3 (YES), it is determined that there is distortion, and the process proceeds to step S36. When it is smaller than the second threshold value TH3 (NO), it is determined as normal and this process is terminated.

  In step S36, the determination unit 54 obtains the side of the read image 20F where the figure eight shape is widened, and proceeds to step S6. In step S6, as in the operation of the first embodiment described with reference to FIG. 7, when the back side A1 of the document 21F is widened, the display unit 35 displays the document 21F on the left side of the display panel 15 as shown in FIG. A distortion image of the document showing the distortion state of the arrangement is displayed, and a message for urging the front side A2 of the bookbinding 20 to be pressed is displayed on the right side, and this processing is terminated. Similarly, when the front side A2 of the original 21F is widened, as shown in FIG. 5, an original distortion image showing a distortion state of the arrangement of the original 21F is displayed on the left side of the display panel 15, and the back of the bookbinding 20 is displayed on the right side. A message prompting to hold side A1 is displayed.

  FIG. 14 is a subroutine showing the figure-shaped determination process in step S36 of FIG.

  In step S36 of FIG. 13, this subroutine is called. In step S41, the determination unit 54 obtains the angle α of the back side A1 among the angles formed by the binding portion 22F obtained in step S32 and the region outline 43a of the low luminance region 24F obtained in step S34. In step S42, when the angle of the back side A1 obtained in step S41 is an acute angle, the angle α of the back side A1 = the binding portion angle φ, and the side where the coordinate value of the coordinate axis Z2 is small (= front side A2) is eight. It is determined that it is the side where the character shape spreads. When the angle α of the back side A1 is an obtuse angle, it is determined that the side with the larger coordinate value of the coordinate axis Z2 (= back side A1) is the side where the figure eight shape is widened, and the process returns to step S6 in FIG.

(Effect of Example 2)
According to the second embodiment, in addition to the effects of the first embodiment, there are the following effects.

  In the second embodiment, when the user presses the back of the bookbinding 20 when the document 21 is placed, an eight-shaped low-luminance region 24F is formed in the vicinity of the binding portion 22F in the read image 20F. In consideration of this, the direction in which the eight-shaped shape of the document 21F spreads is determined based on the binding portion angle φ formed by the region outline 43a on the left side of the low luminance region 24F and the binding portion 22F.

  As described above, since the outer shape outlines 23aF and 23bF of the document 21F in the read image 20F are not used and the spreading direction of the figure-eight shape is determined, all the outline contours 23aF and 23bF of the document 21F are all read image 20F. Even if it is a case where it does not fit within and is interrupted, appropriate guidance can be provided to the user.

(Modification)
The present invention is not limited to the above-described embodiments, and various usage forms and modifications are possible. For example, the following forms (a) to (d) are used as the usage form and the modified examples.

  (A) In the first and second embodiments, the scanner has been described as an example of the image processing apparatuses 10 and 10A. However, the present invention can also be applied to a form in which a personal computer has an image processing apparatus function. Further, the image processing apparatuses 10 and 10A may be facsimile machines, copiers, MFPs (Multi Function Printer / Product / Peripheral), and the like.

  (B) In the first and second embodiments, the document 21 is placed so that the binding unit 22 is parallel to the main scanning direction X of the image sensor 11, and the top 25 of the document 21 is located on the back side A1 with respect to the user. However, the description has been made on the assumption that the ground 26 is placed on the placing table 12 so that the ground 26 is on the near side A2. However, the document 21 is inclined or perpendicular to the main scanning direction X of the image sensor 11. Even when the document 21 is placed, when the layout of the document 21 is distorted, a message to be displayed on the right side of the display panel 15 is, for example, “The document is spread in an eight-letter shape. The present invention can be applied by holding down the back.

  (C) Even with respect to a single-sided original obtained by binding a plurality of single-sided originals, the region outline 43a or the area outline 43b of the binding portion 22F and the low luminance area 24F is used by using the technique described in the second embodiment. By obtaining the above, the present invention can be applied.

  (D) In the first and second embodiments, the book is described as the bookbinding 20 as an example. However, as long as the cover is attached by binding a manuscript, a drawing, a printed matter, etc. Applicable.

DESCRIPTION OF SYMBOLS 10,10A Image processing apparatus 11 Image sensor 12 Mounting table 20F Reading image 21F Original document 22F Binding part 23aF, 23bF Outline outline 24F Low-intensity area 30 Distortion detection part 31 Image reading part 32 Contour extraction part 33 Fore edge angle detection part 34 Determination part 35 Display unit 36 Control unit 50 Distortion detection unit 52 Binding unit extraction unit 53 Binding unit angle calculation unit 54 Determination unit A1 Back side A2 Front side

Claims (7)

An image reading unit that includes a mounting table on which a document having a binding unit and a fore edge is mounted, reads the document placed on the mounting table, and outputs a read image;
A distortion detection unit that detects a distortion state of the original arrangement caused by the binding unit in the read image;
A determination unit that compares a detection result of the distortion detection unit with a first threshold value and determines that the document arrangement is distorted when the distortion state exceeds the first threshold value;
Based on the determination result of the determination unit, a display unit that displays a distortion state of the arrangement in the document and prompts rearrangement;
An image processing apparatus comprising: The distortion detector
A contour extracting unit that extracts an outer contour line indicating the outer shape of the document in the read image;
Of the outline contours, a fore angle formed by the first outline contour indicating the first fore edge of the document and the second outline outline indicating the second fore edge of the document is formed. A fore edge angle detection unit to detect,
The image processing apparatus according to claim 1, further comprising: The fore edge detection unit is
Of the outer contour lines extracted by the contour extraction unit, the first outer contour is defined by using a straight line portion as a first outer contour line indicating the first fore edge and a second outer contour line indicating the second fore edge. The image processing apparatus according to claim 2, wherein an acute angle is detected as the fore edge angle among two angles formed by a line and the second outer contour line. The distortion detector
A binding portion extraction unit that extracts a binding portion of the document in the read image;
A binding portion angle that searches for a luminance value of a pixel in a direction perpendicular to one side with respect to the binding portion to obtain a region contour line of a low-luminance region and calculates a binding portion angle formed by the region contour line and the binding portion A calculation unit,
The determination unit compares the binding unit angle obtained by the binding unit angle calculation unit with a second threshold value. When the binding unit angle exceeds the second threshold value, the document arrangement is distorted. The image processing apparatus according to claim 1, wherein the determination is performed. The binding portion angle calculation unit includes:
The image processing apparatus according to claim 4, wherein an acute angle among two angles formed by the region outline and the binding portion is calculated as the binding portion angle. The determination unit
When it is determined that the document layout is distorted, the acute angle side and the obtuse angle side of the two angles formed by the region outline and the binding portion are identified, and the document spreads in an eight-letter shape toward the obtuse angle side. The image processing apparatus according to claim 4, wherein the image processing apparatus determines that the image processing is performed. The display unit
The image processing apparatus according to claim 1, wherein a document distortion image indicating a distortion state of the arrangement of the document and a message for prompting the rearrangement of the document are displayed.

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