JP2010103808A - Image processor, image reader, image forming apparatus, image processing method, image processing program and computer readable recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor which exactly detects inclination of a document and size of the document, and by which a high quality image with successful appearance is obtained as an image after correction of the inclination of document and correction of document size. <P>SOLUTION: A color image processor 1 has: a document inclination and size detection part 8 which detects an inclination angle of the document to a scanning direction or sub scanning direction, and the size of the document from preimage data which are obtained by starting reading of the document when an angle which is formed by a document loading surface of a document table and the opposite surface of a document cover to the document loading surface is γ; and a document inclination and size correction part 9 which corrects the angle of the document and the size of the document on the basis of detection results of the document inclination and size detection part 8 to main image data which is obtained by starting reading of the document after the document cover is closed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing apparatus and the like for processing digital image data obtained by reading a document with a reading unit such as a scanner, and more particularly to image data read from a document that is tilted when a document cover is closed. The present invention relates to an image processing apparatus that detects inclination and size.

  2. Description of the Related Art Conventionally, some digital image forming apparatuses such as digital copying machines can automatically correct a document by obtaining the tilt from the digital image data even when the document is placed tilted with respect to the scanning direction of the reading unit.

With regard to a technique for correcting such an inclination, Patent Document 1 discloses that a platen glass side surface of a conveyor belt is colored orange, an edge that changes from black to white, and an edge that changes from white to black. Is detected, a change in the inclination between the coordinate data of each document edge is detected, a point where the inclination changes (edge change point) is obtained, a line segment connecting the edge change points is extracted, and the extracted line segment Among them, a technique for detecting and correcting inclination by selecting a line segment having an inclination of 45 ° or less with respect to the sub-scanning direction is disclosed.
JP 11-331547 (published on November 30, 1999)

  However, in the technique of the above-mentioned Patent Document 1, there is a possibility that a colored portion on the back may remain at the edge of the image after the inclination correction, and the output image may not be very beautiful in appearance.

  The present invention has been made in view of the above-described problems, and its purpose is to accurately detect the inclination of the original and the size of the original, and as an image after the correction of the original inclination and the correction of the original size, An object of the present invention is to provide an image processing apparatus, an image reading apparatus, an image forming apparatus, an image processing method, an image processing program, and a computer-readable recording medium capable of obtaining a high-quality image with a good appearance.

  In order to solve the above problems, an image processing apparatus according to the present invention provides a document table and a document cover that can be opened and closed with respect to the document table for covering a document placed on a document placement surface of the document table. And an angle formed between the document placement surface and the surface of the document cover facing the document placement surface of the document reading unit that reads the document placed on the document placement surface is 0 From the first image data obtained when the original reading unit starts reading the original when the first angle is large, the inclination angle of the original with respect to the scanning direction or the sub-scanning direction of the reading, A document inclination / size detection unit for detecting the size, and the document inclination / size with respect to second image data obtained by the document reading unit starting reading the document after the document cover is closed. Detection result of the detector Based, it is characterized by comprising: a document skew size correction unit that corrects a size of the original angle and the document, the.

  According to the above configuration, when the angle formed by the document placement surface of the document table and the surface of the document cover facing the document placement surface (the angle formed by the document table and the document cover) is a first angle greater than zero. That is, in the operation process of the user holding the document with the document cover, the document is read, the first image data is obtained, and the inclination of the document and the size of the document are obtained. Then, the result is used for the correction process for the second image data obtained after the document cover is closed. Therefore, it is possible to correct the inclination of the original and the size of the original without leaving a black background in the corrected image while obtaining the same inclination / size detection processing accuracy as that at the time of the black background. Therefore, according to the above configuration, the inclination of the document and the size of the document can be accurately detected, and a high-quality image with a good appearance can be obtained as an image after the correction of the document inclination and the correction of the document size.

  In order to solve the above problems, an image reading apparatus according to the present invention includes the image processing apparatus according to the present invention, the document table, the document cover, and a reading output unit that reads the document and outputs image data. And an original reading unit. According to this configuration, since the image reading apparatus according to the present invention includes the image processing apparatus according to the present invention, it is possible to accurately detect the inclination of the original and the size of the original, and to correct the inclination of the original and the correction of the original size. As a subsequent image, a high-quality image with a good appearance can be obtained. Therefore, it is possible to provide an image reading apparatus that can detect and correct the inclination and size of a document with a simple method with high accuracy.

  In the image reading apparatus according to the present invention, in addition to the above-described configuration, the document reading unit has an angle formed by the document placement surface of the document table and a surface of the document cover facing the document placement surface. The document reading unit may start the reading when an angle detected by the detection unit is changed from an angle larger than the first angle to the first angle.

  According to the above configuration, the first image data obtained by starting reading the original when the angle formed by the original platen and the original cover is the first angle, and the original when the original cover is closed. It is possible to output the second image data obtained by starting the reading by the original reading unit.

  In the image reading apparatus according to the present invention, in addition to the above configuration, the document reading unit may accept a change in the first angle by a user. According to this configuration, the user can freely set the first angle, and can set a value according to the user's usage pattern.

  In the image reading apparatus according to the present invention, in addition to the above configuration, the detection unit may be an optical rotary encoder or an optical linear encoder. According to this configuration, since the optical encoder has high resolution, the angle formed by the document table and the document cover can be accurately detected. Moreover, according to the said structure, the freedom degree of the setting value of an angle can be made high, and it becomes easy to make the setting value of an angle into a value according to a user's usage form.

  In addition to the above configuration, the image reading apparatus according to the present invention includes a document inclination / size correction mode for operating the document inclination / size detection unit and the document inclination / size correction unit, the document inclination / size detection unit, A mode control unit for switching between a non-correction mode in which the document inclination / size correction unit is not operated may be provided.

  According to the above configuration, when document skew / size correction is not required, reading the document for generating the pre-image data can be omitted by setting the non-correction mode. Therefore, the operation of the apparatus for generating the pre-image data is not necessary, and power saving and apparatus consumption can be suppressed.

  In order to solve the above problems, an image forming apparatus according to the present invention includes any one of the above-described image reading apparatuses. According to this configuration, since the image forming apparatus according to the present invention includes the image reading apparatus having the image processing apparatus according to the present invention, it is possible to accurately detect the inclination of the original and the size of the original, and to correct the inclination of the original. In addition, a high-quality image that looks good can be obtained as the image after the correction of the document size. Therefore, the image forming apparatus of the present invention can form an image with improved image quality.

  In order to solve the above problems, an image processing method according to the present invention provides a document table and a document cover that can be opened and closed with respect to the document table for covering a document placed on a document placement surface of the document table. And an angle formed between the document placement surface and the surface of the document cover facing the document placement surface of the document reading unit that reads the document placed on the document placement surface is 0 From the first image data obtained when the original reading unit starts reading the original when the first angle is large, the inclination angle of the original with respect to the scanning direction or the sub-scanning direction of the reading, A document inclination / size detection step for detecting the size of the document, and a second document data obtained when the document reading unit starts reading the document after the document cover is closed. Size detection step Based on the detection result of the flop, it is characterized in that it comprises a document skew-size correction step of correcting the size of the original angle and the document, the.

  According to the above method, the same effect as the image processing apparatus can be obtained, the inclination of the original and the size of the original can be accurately detected, and the image after the correction of the original inclination and the correction of the original size can be viewed with high quality. You can get a good picture. Therefore, it is possible to accurately detect and correct the document inclination and document size with a simple method.

  Further, the image processing apparatus according to the present invention may be realized by a computer. In this case, image processing that causes the image processing apparatus to be realized by the computer by causing the computer to operate as each unit in the image processing apparatus. A program and a computer-readable recording medium on which the image processing program is recorded also fall within the scope of the present invention.

  According to these configurations, the same operational effects as those of the image processing apparatus can be realized by causing the computer to read and execute the image processing program.

  In the image processing apparatus according to the present invention, as described above, the angle formed by the document placement surface of the document table and the surface of the document cover facing the document placement surface is a first angle greater than zero. Sometimes, from the first image data obtained when the original reading unit starts reading the original, the inclination angle of the original with respect to the scanning direction or the sub-scanning direction of the reading and the size of the original are detected. A detection result of the document inclination / size detection unit for the second image data obtained when the document reading unit starts reading the document after the document cover is closed and the document inclination / size detection unit. And a document inclination / size correction unit for correcting the angle of the document and the size of the document.

  According to the above configuration, when the angle formed by the document placement surface of the document table and the surface of the document cover facing the document placement surface (the angle formed by the document table and the document cover) is a first angle greater than zero. That is, in the operation process of the user holding the document with the document cover, the document is read, the first image data is obtained, and the inclination of the document and the size of the document are obtained. Then, the result is used for the correction process for the second image data obtained after the document cover is closed. Therefore, it is possible to correct the inclination of the original and the size of the original without leaving a black background in the corrected image while obtaining the same inclination / size detection processing accuracy as that at the time of the black background. Therefore, according to the above configuration, the inclination of the document and the size of the document can be accurately detected, and a high-quality image with a good appearance can be obtained as an image after the correction of the document inclination and the correction of the document size.

[Embodiment 1]
(Image forming apparatus and image processing apparatus)
A digital color copying machine which is an embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a digital color copying machine (image forming apparatus) 2 having a color image processing apparatus 1 which is an embodiment of an image processing apparatus according to the present invention. As shown in FIG. 1, the digital color copying machine 2 includes a color image processing device 1, a color image input device (original reading unit) 3, and a color image output device 4.

  The color image input device 3 includes a scanner unit including a device that converts optical information into an electrical signal, such as a CCD (photoelectric conversion element) line sensor, and outputs a reflected light image from an original as an RGB analog signal. To do.

  The analog signal read by the color image input device 3 is, as a general rule, an A / D (analog / digital) conversion unit 5, a shading correction unit 6, an input tone correction unit 7, an original in the color image processing device 1. Send in the order of inclination / size correction unit 9, area separation processing unit 10, color correction unit 11, black generation and under color removal unit 12, spatial filter processing unit 13, output tone correction unit 14, and tone reproduction processing unit 15. Then, it is output to the color image output device 4 as a CMYK digital color signal.

  Further, the color image processing apparatus 1 has a document inclination / size detection unit 8, and this document inclination / size detection unit 8 performs processing using data from the input gradation correction unit 7. Not pipeline processing.

  The A / D converter 5 converts RGB analog signals into digital signals. The shading correction unit 6 performs a process of removing various distortions generated in the illumination system, the imaging system, and the imaging system of the color image input device 3 on the digital RGB signal sent from the A / D conversion unit 5. .

  The input tone correction unit 7 performs image quality adjustment processing such as background density removal and contrast on the RGB signal from which various distortions have been removed by the shading correction unit 6.

  Here, in the present embodiment, when the document skew / size correction function (document skew / size correction mode) is selected from the optional functions (special functions) in the copier mode (copy processing mode) (see FIG. 18). Pre-image data (RGB signal, first image data) is generated by a pre-scan described later, and main image data (RGB signal, second image data) is generated by a main scan described later. Specifically, the pre-image data and the main image data are generated by performing pre-scan and main scan on the same document. The main image data is sent from the input gradation correction unit 7 to the document inclination / size correction unit 9, and the pre-image data is sent from the input gradation correction unit 7 to the document inclination / size detection unit 8.

  The document inclination / size detection unit 8 extracts an edge of the document from the RGB signal that has been input gradation corrected by the input gradation correction unit 7, and corrects correction parameters (angle of inclination, corrected size, correction processing start). Position).

  In the document inclination / size correction unit 9, when the document inclination / size correction function is selected as described above, the input tone correction unit 7 is used by using the correction parameter calculated by the document inclination / size detection unit 8. The image of the main image data (RGB signal) output from the image is subjected to an inclination / size correction process for correcting the inclination of the original and the size of the original and is stored in the image memory 16. Note that the document inclination / size correction unit 9 does not process the RGB signal acquired from the input tone correction unit 7 when the document inclination / size correction function is not selected, and directly performs the region separation processing unit 10. Send to. A detailed description of the document inclination / size detection unit 8 and the document inclination / size correction unit 9 will be described later.

  The region separation processing unit 10 separates each pixel in the input image into a plurality of regions including a character region, a halftone dot region, and a photograph region based on the RGB signal. Based on the separation result, the region separation processing unit 10 sends a region identification signal indicating to which region the pixel belongs to the black generation and under color removal unit 12, the spatial filter processing unit 13, and the gradation reproduction processing unit 15. In addition to the output signal, the input signal output from the input tone correction unit 7 (when the document inclination / size correction process is performed, the corrected data stored in the image memory 16 is corrected by the document inclination / size correction unit 9). ) As it is to the subsequent color correction unit 11.

  The color correction unit 11 performs a process of removing color turbidity based on the spectral characteristics of the CMY color material including unnecessary absorption components in order to achieve faithful color reproduction.

  The black generation and under color removal unit 12 generates a new CMY signal by generating a black (K) signal from the CMY three-color signal after color correction, and subtracting the K signal obtained by black generation from the original CMY signal. Perform the process. By these processes, the CMY three-color signal is converted into a CMYK four-color signal.

  The spatial filter processing unit 13 performs spatial filter processing using a digital filter on the image data of the CMYK signal input from the black generation and under color removal unit 12 to correct the spatial frequency characteristics. As a result, blurring of the output image and deterioration of graininess can be reduced.

  Similar to the spatial filter processing unit 13, the gradation reproduction processing unit 15 performs predetermined processing described later on the image data of the CMYK signal based on the region identification signal. For example, in the region separated into characters by the region separation processing unit 10, a filter having a high enhancement amount of the high frequency component is used as the spatial filter in the spatial filter processing unit 13 in order to improve the reproducibility of characters. At the same time, the tone reproduction processing unit 15 performs binarization or multi-value processing using a high-resolution screen suitable for reproducing high-frequency components.

  Further, with respect to the region separated into halftone dots by the region separation processing unit 10, the spatial filter processing unit 13 performs low-pass filter processing for removing the input halftone component. The output tone correction unit 14 performs output tone correction processing for converting a signal such as a density signal into a halftone dot area ratio that is a characteristic value of the color image output device 4. A gradation reproduction process is performed in which the image is finally separated into pixels and each gradation is reproduced.

  In addition, for a region separated into photographs by the region separation processing unit 10, binarization or multi-value processing is performed on a screen with an emphasis on gradation reproducibility.

  The image data subjected to the above-described processes is temporarily stored in a storage device (not shown), read at a predetermined timing, and input to the color image output device 4. The color image output device 4 outputs image data onto a recording medium such as paper. For example, a color image output device using an electrophotographic method or an ink jet method can be used, but the color image output device 4 is particularly limited. Not.

  The digital color copying machine 2 includes a setting button for controlling the operation of the digital color copying machine 2, an operation panel including a numeric keypad, a display unit such as a liquid crystal display, and the like. The above processing is controlled by a CPU (Central Processing Unit) (not shown). In this embodiment, the color image processing apparatus 1 has been described as a component of the digital color copying machine 2, but the color image processing apparatus 1 has a copier function, a printer function, a facsimile transmission function, a scan to e-mail function, and the like. May be included in a multifunction peripheral (image processing apparatus). Further, it may be a monochrome copying machine instead of a color copying machine.

(Image input device)
Next, the configuration of the color image input device 3 will be described. FIG. 2 is a diagram illustrating an example of the configuration of the color image input device 3. As shown in FIG. 2, the color image input device 3 includes an upper casing 510 having a document conveying section, a lower casing 560 having a scanner section (reading output section), and a discharge tray 566 on which discharged documents are placed. Etc.

  A document set sensor 514 that detects a document placed on the document tray 511, a call roller 512 for conveying the document one by one, and a document for reading an image on the document are conveyed to the upper casing 510. Conveying rollers 513a and 513b, a document discharge roller 50 for discharging a document, a document discharge sensor 567 for detecting a document to be discharged, and the like are provided.

  The conveyance roller 513b functions as an alignment roller for aligning the paper direction. The conveyance roller 513b includes an electromagnetic clutch (not shown) on the drive shaft, can control transmission of driving force from a drive motor (not shown), and is stopped when there is no document. Then, when the leading edge of the document comes into contact with the feeding timing sensor 515 and a predetermined signal is transmitted from this sensor, the document is set to rotate in the direction in which the document is conveyed downstream. The transport roller 513b is stopped and the leading edge of the document transported from the upstream side comes into contact with the nip portion of the transport roller 513b to form a predetermined deflection and transport the document downstream. It rotates as follows. At this time, the leading edge of the document is aligned by the nip portion of the conveying roller 513b so as to be perpendicular to the conveying direction.

  In the present embodiment, as shown in FIG. 2, the upper housing 510 covers the document placed on the document placement surface of the document table 561, that is, the upper housing 510 is a document. Corresponds to the cover. Therefore, the reference numeral 510 is attached to the document cover below. The document cover 510 can be opened and closed with respect to the document table 561.

  The lower housing 560 is provided with scanning units 562 and 563 that reciprocate in parallel along the lower surface of the document table (platen glass) 561, an imaging lens 564, a CCD line sensor 565 that is a photoelectric conversion element, and the like. .

  The scanning unit 562 has a light source 562a (for example, a halogen lamp) for irradiating light on a document conveyed from the document tray 511 or a document placed on the document table 561, and light reflected by the document is predetermined. And a mirror 562b for guiding it to the optical path. The scanning unit 563 also includes mirrors 563a and 563b for guiding the light reflected from the document to a predetermined optical path. The scanning unit 563 includes mirrors 563a and 563b for guiding the light reflected from the document and guided from the mirror 562b to the CCD line sensor 565.

  The imaging lens 564 images the reflected light guided from the scanning unit 563 at a predetermined position on the CCD line sensor 565. The CCD line sensor 565 photoelectrically converts the formed optical image and outputs an electrical signal. That is, based on a color image read from an original (for example, the surface of the original), data that is color-separated into R (red), G (green), and B (blue) color components is output to the color image processing apparatus 1. .

  Here, in the present embodiment, when the document skew / size correction function is selected, pre-scanning is performed before a copy execution command is input (before the copy button is pressed). The prescan will be described. When the user performs the operation of closing the document cover (document mat) 510 when the document skew / size correction function is selected, the color image input device 3 performs prescanning on the document placed on the document table 561. The pre-image data (first image data) is generated and transmitted to the color image processing apparatus 1. In the present embodiment, the upper housing 510 in FIG. 2 corresponds to the document cover. Therefore, in the following, the document cover 510 is used. After the user starts the operation of closing the document cover 510, the color image input device 3 moves to the document placement surface of the document table 561 and the document placement surface of the document cover 510 as shown in FIG. Is set on the document table 561 as a trigger when the angle formed by the opposite surface (hereinafter referred to as the angle between the document table 561 and the document cover 510) is γ (γ> 0 °, first angle). Pre-scanning is started on the placed document, and pre-image data (first image data) that becomes a scanned image as shown in FIG. 9B is generated.

  Further, as shown in FIG. 10A, when the document cover 510 is completely closed (γ = 0 °) and the copy button is pressed, the color image input device 3 is placed on the document table 561. A main scan is started with respect to the document, and main image data to be a scan image as shown in FIG. 10B is generated. The scanned image at this time includes the back white plate of the document cover 510 (the surface of the document cover that faces the document table 561).

  The color image input device 3 sequentially transmits the pre-image data and the main image data generated as described above to the color image processing device 1. As described above, the pre-image data transmitted to the color image processing apparatus 1 is input to the document inclination / size detection unit 8 via the A / D conversion unit 5, the shading correction unit 6, and the input tone correction unit 7. To do. On the other hand, the main image data transmitted to the color image processing apparatus 1 is sent through the A / D conversion unit 5, the shading correction unit 6, and the input tone correction unit 7 as described above, and the document inclination / size correction unit 9. To enter.

(Original tilt / size detector)
Next, processing in the document inclination / size detection unit 8 will be described. FIG. 3 is a block diagram showing an internal configuration of the document inclination / size detection unit 8. As shown in FIG. 3, the document inclination / size detection unit 8 includes an edge detection processing unit 81, a parameter calculation unit 82, and a determination unit 83.

  For example, the pre-image data (area read by the scanner) as shown in FIG. 4 received from the input tone correction unit 7, the edge detection processing unit 81 has a threshold Th (with a pixel value of an adjacent pixel for each line. Among pixels larger than a value larger than a value that does not detect unevenness in a region other than the document that occurs when the angle between the document cover 510 and the document table 561 is γ, for example, 40) The coordinates of the leftmost pixel and the coordinates of the rightmost pixel are calculated as edge coordinates. Then, from the edge coordinates calculated for all lines of the pre-image data, the edge coordinates that are the top, bottom, left, and right are respectively (EdgeTx, EdgeTy), (EdgeBx, EdgeBy), (EdgeLx, EdgeLy) ), (EdgeRx, EdgeRy) are extracted.

  The parameter calculation unit 82 is a block for calculating a document inclination / size correction parameter (hereinafter referred to as a correction parameter) used in the document inclination / size correction process in the document inclination / size correction unit 9.

  The parameter calculation unit 82 is based on the edge coordinates (EdgeTx, EdgeTy) and (EdgeLx, EdgeLy) that are the uppermost and leftmost of the edge coordinates detected by the edge detection processing unit 81, and the inclination (angle) of the document. Is calculated. When the pre-image data is shown in FIG. 13, tan α (tangent) can be obtained from the following equation (1), where α is the inclination angle of the read document.

Tanα = (EdgeTy-EdgeLy) / (EdgeTx-EdgeLx) (1)
Then, the angle α corresponding to this value is read from a previously created table as shown in FIG. 5, for example. When the read angle α is 45 ° or less, (EdgeLx, EdgeLy) is set as the correction processing start coordinates (StartX, StartY). When the angle α exceeds 45 °, the angle α is converted by the following equation (2), and (EdgeTx, EdgeTy) is set as the correction processing start coordinates (StartX, StartY).

α = α-90 (2)
Next, the original vertex coordinates (EdgeTx ', EdgeTy'), (EdgeBx ', EdgeBy'), (EdgeLx ', EdgeLy'), (EdgeRx ', EdgeRy') when the calculated angle α is corrected are as follows: Calculated according to equation (3).

Here, X is any one of T, B, L, and R.

  From the corrected document vertex coordinates calculated by equation (3), the corrected document height (corrected document height) and corrected document width (corrected document width) are respectively expressed by the following equations ( 4) Calculated according to (5).

Document height after correction = MAX (EdgeTy ', EdgeBy', EdgeLy ', EdgeRy')-MIN (EdgeTy ', EdgeBy', EdgeLy ', EdgeRy') (4)
Document width after correction = MAX (EdgeTx ', EdgeBx', EdgeLx ', EdgeRx')-MIN (EdgeTx ', EdgeBx', EdgeLx ', EdgeRx') (5)
The corrected document height and corrected document width calculated here are used as the document size after the document skew / size correction. In the present embodiment, the original size is not a standard size, but the corrected original height and corrected original width calculated by the above processing. In addition, the correspondence relationship between the calculated corrected document height and corrected document width with a standard size sheet is stored as a sheet size table for each output resolution. For example, FIG. 6 shows an example of a paper size table when the resolution is 300 dpi.

  A paper size determination method will be described using a paper size table. The process for determining the paper size is performed by the determination unit 83. First, the paper size is narrowed down in the first range where the calculated corrected document width is less than or equal to the width of the paper size table, and the first paper size whose height in the paper size table is the corrected document height is set as the paper size. Set. For example, referring to FIG. 6, when the corrected document width calculated at 300 dpi is 2480 and the corrected document height is 3500, first, from the sheet width column of the output sheet size table. , A4 or A5R, and A4 is selected as the paper size from the height column.

  Note that the set value of the output paper size table is set to the number of pixels that is about 10 mm larger than the actual size in consideration of the error of the size detection result.

  The document inclination / size detection unit 8 calculates, as correction parameters, “original inclination angle α”, “original size after original inclination / size correction (hereinafter referred to as corrected original size)”, “correction”. “Processing start coordinates” is sent to the document inclination / size correction unit 9.

(Original skew / size correction section)
Next, the inclination / size correction processing in the original inclination / size correction unit 9 will be described. In the present embodiment, for example, an affine transformation process using a rotation matrix can be used as the inclination / size correction process. This affine transformation process will be described in detail below.

  First, in general, coordinates (x ′, y ′) obtained by rotating coordinates (x, y) by θ can be obtained from the following equation (6).

  Here, since the document inclination / size correction unit 9 processes the pixel and the pixel value of the image as coordinates and coordinate values, the coordinate (m, n) will be described as a pixel (m, n) hereinafter.

  As shown in FIG. 7, in order to output the pixel value Z of the pixel (x ′, y ′), the coordinate value of the pixel (x ′, y ′) is an integer, and the pixel (x ′, y ′) The pixel (x, y) before rotation is defined as the pixel (xs + StartX, ys + StartY) (xs + StartX and ys + StartY are real numbers), and the pixel value Z of the pixel (xs + StartX, ys + StartY) is bilinear Obtained by interpolation such as modulo.

  Specifically, the pixel (xs + StartX, ys + StartY) before the rotation of the pixel (x ′, y ′) can be obtained by the following equation (7) which is an inverse transformation equation of the above equation (6). .

Then, in the xy coordinate system of the pre-rotation image shown in FIG. 7, pixels (x _i , y _j ), (x _{i + 1} , y) located at four points around the pixel (xs + StartX, ys + StartY) _j ), (x _i , y _{j + 1} ), (x _{i + 1} , y _{j + 1} ), by substituting the pixel values Z _{1 to} Z ₄ into the following equation (8), the pixel (xs + StartX, ys + StartY), that is, the pixel value Z of the pixel (x ′, y ′) can be obtained. Where x _i ≤xs + StartX <x _{i + 1} , y _j ≤ys + StartY <y _{j + 1} , | x _{i + 1} -xs |: | xs-x _i | = (1-u): u | Y _{j + 1} -ys |: | ys-y _j | = (1-v): v (where u and v are both 0 or more and less than 1).

  If the trigonometric ratio values (sine value and cosine value) used in the affine transformation are also stored in a table as shown in FIG. 5, the calculation speed can be increased. For the pixel (x ′, y ′) after rotation correction, 0 ≦ x ′ <corrected document width and 0 ≦ y ′ <corrected document height.

  When the correction parameter is sent from the determination unit 83 of the document inclination / size detection unit 8, the document inclination / size correction unit 9 is read by a main scan (to be described later) and the input gradation correction unit 7 performs image quality adjustment processing. The original inclination / size correction processing is performed on the main image data after being applied.

  Specifically, the document inclination / size correction unit 9 first performs correction processing start coordinates and an inclination angle α among the correction parameters sent from the document inclination / size detection unit 8 as processing for correcting the document inclination. Is used to perform affine transformation on the main image data so that the original image shown in the main image data is rotated by an angle α with the correction processing start coordinate as a fulcrum. Here, the document inclination / size correction unit 9 specifies an image range in which the document inclination is corrected using the size-corrected document size received from the document inclination / size detection unit 8. Further, at the time of the inclination correction by the affine transformation, the pixel value necessary for calculating the value of each coordinate of the output image is acquired and the interpolation process is performed, so that the inclination correction and the size correction are performed at the same time. .

  The document skew / size correction processing has been described above. Either the correction of the document inclination or the correction of the document size may be performed first or simultaneously.

(Document skew / size detection process)
Next, an operation procedure of the user and a processing flow of the digital color copying machine 2 when the document inclination / size correction function is selected in the digital color copying machine 2 of the present embodiment will be described. FIG. 8 is a flowchart showing a user operation procedure and a processing flow of the digital color copying machine 2 when the document skew / size correction function is selected. FIG. 11 is a flowchart showing the processing flow of the document inclination / size correction unit 9.

  As shown in FIG. 8, the user sets a document on the document table 561 of the color image input device 3 (S1), and starts an operation of closing the document cover 510 (S2). Here, as shown in FIG. 9A, the color image input device 3 detects whether the angle formed by the document cover 510 and the document table 561 is γ (for example, 60 °) (S3), If it is not (NO in S3), S3 is repeated until γ is detected. If it is detected that γ is detected (YES in S3), the document placed on the document table 561 is pre-scanned. (S4). At the time of pre-scanning, the scanned image is in a state where the document cover 510 is half open, so that the area other than the document is black as shown in FIG. 9B, and the difference between the background color of the document and the area other than the document is normal. It becomes clearer than when scanning.

  The pre-image data obtained by the pre-scan of the original is sent to the original inclination / size detection unit 8, and the original inclination / size detection unit 8 detects the edge of the image of the pre-image data and corrects it as described above. As parameters, the document tilt angle α, document tilt / size corrected document size, and correction processing start coordinates are specified (detected) (S5).

  Thereafter, the color image input device 3 confirms that the user has pressed the copy button after the document cover 510 is completely closed (S6). If it cannot be confirmed that the copy button has been pressed (NO in S6), S6 is repeated until the copy button is pressed. If it is confirmed that the copy button has been pressed (YES in S6), the color image input device 3 performs a main scan on the document placed on the document table 561 (S7). The main image data obtained by the main scan is sent to the color image processing apparatus 1, subjected to image quality adjustment processing by the input tone correction unit 7, and then stored in the image memory 16 (S 8).

  Thereafter, as shown in FIG. 11, the document inclination / size correction unit 9 reads the main image data stored in the image memory 16 (S101). Then, the document inclination / size correction unit 9 uses the correction parameters from the document inclination / size detection unit 8 and uses the above formulas (6) to (8) to the main image data read in S101. The inclination / size correction is performed (S102), and the image data after the inclination / size correction is stored in the image memory 16 (S103).

  Thereafter, the image data corrected for inclination and size is read from the image memory 16 and sent to the subsequent region separation processing unit 10 to sequentially perform pipeline processing. These processes are performed under the control of the control unit (CPU) as described above.

(Angle detection mechanism)
According to the present embodiment, the color image input device 3 starts pre-scanning with the angle formed by the document table 561 and the document cover 510 being γ. Therefore, the configuration of the apparatus is that the color image input apparatus 3 is provided with an angle detection mechanism that detects an angle formed between the document table 561 and the document cover 510. A control unit (not shown) that controls the color image input apparatus 3 causes the color image input apparatus 3 to perform pre-scanning when the angle detected by the angle detection mechanism becomes γ.

  An example of the angle detection function is an optical linear encoder (detection unit). Below, a linear encoder is demonstrated based on figures.

  12A and 12B are schematic views showing an optical linear encoder 120 which is an example of an angle detection mechanism. FIG. 12A shows a state of the linear encoder 120 when the document cover 510 is fully opened, and FIG. Shows the state of the linear encoder 120 when the angle between the document table 561 and the document cover 510 is γ, and (c) shows the state of the linear encoder 120 when the document cover 510 is completely closed. The linear encoder 120 includes a sensor holding base 121, photosensors 122 and 123, and an actuator 124.

  13A is a top view of the photosensors 122 and 123 and the actuator 124 included in the linear encoder 120 of FIG. 12, and FIG. 13B is a front view of the photosensors 122 and 123 and the actuator 124. FIG. 13C is a side view of the photosensors 122 and 123 and the actuator 124.

  The linear encoder 120 shown in FIGS. 12 and 13 has an actuator 124 provided with a plurality of slits. When the slit is positioned between the light emitting element 125 and the light receiving element 126 of the photosensors 122 and 123, a signal output from the photosensor 123 is turned on. That is, depending on the open / close state of the document cover 510, the actuator 124 moves in the vertical direction, and the signal waveform output from the photosensor 123 changes.

  As shown in FIG. 12, the linear encoder 120 has a sensor holding base 121 for supporting the actuator 124. The sensor holding base 121 is shaped like a cylinder, and a spring or the like is inserted so that the actuator 124 can move up and down.

  14 shows that the document cover 510 and the linear encoder 120 are in the fully closed state shown in FIG. 12C from the fully opened state shown in FIG. 12A through the angle γ state shown in FIG. It shows changes in the signal waveforms of the photosensors 122 and 123 when transitioning to a state. Then, by detecting the period indicated by reference numeral 127 in FIG. 14, it is possible to detect that the angle between the document table 561 and the document cover 510 is γ. Note that the value of γ can be freely set on condition that a slit is provided between the light emitting element and the light receiving element of the photosensors 122 and 123.

  Another example of the angle detection mechanism is an optical rotary encoder (detection unit). Below, a rotary encoder is demonstrated based on figures.

  15A and 15B are schematic views showing the optical rotary encoder 150. FIG. 15A shows the state of the rotary encoder 150 when the document cover 510 is fully opened, and FIG. 15B shows the document table 561 and the document cover. The state of the rotary encoder 150 when the angle formed with 510 is γ is shown, and (c) shows the state of the rotary encoder 150 when the document cover 510 is completely closed. FIG. 16 is a view of the rotary encoder 150 viewed from the direction of the arrow shown in FIG.

  As shown in FIGS. 15 and 16, the rotary encoder 150 includes a disc 151 and photosensors 152 and 153. The disc 151 rotates in conjunction with the movement of the document cover 510, and a plurality of slits are formed along the circumferential direction. The photo sensor 152 and the photo sensor 153 are arranged at an angle of 90 degrees with respect to each other.

  As shown in FIG. 16, the slits formed in the disk 151 pass between the light emitting element 154a and the light receiving element 155a of the photosensor 152 as the disk 151 rotates. Yes. Further, a slit formed in the disk 151 is positioned between the light emitting element 154b and the light receiving element 155b of the photosensor 153 only at the timing when the document cover is completely closed.

  17 shows that the document cover 510 and the rotary encoder 150 are fully closed as shown in FIG. 15C from the fully open state shown in FIG. 15A through the angle γ state shown in FIG. 15B. It shows changes in signal waveforms of the photosensors 152 and 153 when transitioning to a state. Then, by detecting the ON period of the photosensor 152 indicated by reference numeral 156 in FIG. 17, it is possible to detect that the angle formed between the document table 561 and the document cover 510 is γ. Note that the value of γ can be freely set on condition that a slit is provided between the light emitting element 154a and the light receiving element 155b of the photosensor 152.

  The digital color copying machine 2 according to the present embodiment is configured to execute document skew / size correction when the document skew / size correction function is selected as a special function in the copy processing mode. In other words, in the digital color copying machine 2 of the present embodiment, the original inclination / size correction mode (mode for selecting the original inclination / size correction function) for operating the original inclination / size detection unit 8 and the original inclination / size correction unit 9 is set. , It is possible to switch to a non-correction mode that does not operate (a mode in which the document skew / size correction function is not selected). This is performed by a control unit (mode control unit) (not shown). FIG. 18 shows a screen displayed on an operation panel (not shown) for selecting the original skew / size correction function and showing various menus of special functions.

  The control unit (not shown) of the digital color copying machine 2 displays various menus of special functions shown in FIG. 18, and the control unit accepts that the user has selected “original skew / size correction” from among them. Then, a menu screen for document inclination / size correction as shown in FIG. 19 is displayed. The menu screen of FIG. 19 is a screen for allowing the user to select the setting state of the document skew / size correction function. In the menu screen of FIG. 19, an “always set” button and a “confirm every scan” button are displayed, and the user is requested to select. Here, when the user selects the “confirm every scan” button and accepts that the control unit always sets the document tilt / size correction function, copying or filing (processing for reading and transmitting the document) The document inclination / size detection unit 8 always functions when performing the above, and the document inclination / size correction unit 9 performs document inclination / size correction processing.

  When the “always set” button is selected by the user, the control unit accepts that the document skew / size correction function is always set, and displays the menu screen shown in FIG. The image shown in FIG. 20 is an image that allows the user to select whether or not to display a usage procedure for document skew / size correction. On the menu screen of FIG. 20, a “Yes” button and a “No” button for displaying the usage procedure are displayed, and the user is requested to select.

  Although not shown, a screen for setting the angle γ between the document cover 510 and the document table 561 when performing pre-scanning, the threshold value Th, and the like may be displayed on the operation panel.

  As described above, in the present embodiment, from the pre-image data obtained when the document inclination / size detection unit 8 starts reading the document when the angle between the document table 561 and the document cover 510 is γ, As the correction parameters, the document inclination angle α with respect to the scanning direction or the sub-scanning direction, the corrected document size, and the correction processing start coordinates are specified. Then, the document inclination / size correction unit 9 applies the original image data obtained by starting the reading of the document after the document cover is closed based on the output result of the document inclination / size detection unit 8. Correct the angle and document size. According to the configuration of the present embodiment, it is possible to accurately detect the inclination of the original and the size of the original, and a high-quality image with a good appearance can be obtained as an image after the correction of the original inclination and the correction of the original size.

[Embodiment 2]
In this embodiment, a digital color copying machine according to another embodiment of the image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 21 is a block diagram showing a configuration of a digital color copying machine (image forming apparatus) 200 having a color image processing apparatus 1 ′ which is another form of the image processing apparatus according to the present invention. The digital color copying machine 200 of this embodiment includes a color image processing apparatus 1 ′, a color image input apparatus 3, and a color image output apparatus 4.

  In the present embodiment, as shown in FIG. 21, the color image processing apparatus 1 ′ is separated into a pre-processing unit 1 a and a post-processing unit 1 b, and the output of the pre-processing unit 1 a is stored in an image storage device (HDD) 201. Then, a mode in which data read from the image storage device 201 is processed as input data of the post-processing unit 1b and finally an image is output will be described. Note that devices or blocks having the same functions as those in Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

  The pre-processing unit 1 a includes an A / D conversion unit 5, a shading correction unit 6, an input tone correction unit 7, and a document inclination / size detection unit 8. The main image data (image data obtained by the main scan) processed by the input tone correction unit 7 of the pre-processing unit 1 a is stored in the image storage device 201. If the document skew / size correction processing function is selected at the same time, pre-image data obtained by prescanning is sent to the document skew / size detection unit 8. Then, the document inclination / size detection unit 8 obtains correction parameters (angle α, corrected document size, correction processing start coordinates), and stores them in the image storage device 201 in association with the main image data.

  On the other hand, the post-processing unit 1b includes a document inclination / size correction unit 9, a region separation processing unit 10, a color correction unit 11, a black generation and under color removal unit 12, a spatial filter processing unit, an output gradation correction unit 14, and a gradation reproduction. A processing unit 15 is provided. The main image data after the input tone correction stored in the image storage device 201 and the correction parameters stored in association therewith are read out, and the result of coordinate conversion by the document inclination / size correction unit 9 is sequentially processed in the subsequent stage. The image data is stored in the image memory 16b connected to the unit 1b.

  The region separation processing unit 10 performs region separation processing on the main image data after the inclination / size correction stored in the image memory 16b. Subsequent processing units proceed with the pipeline method.

  According to the configuration of the present embodiment described above, in the color image processing apparatus 1 ′, it is possible to cause the processing of the pre-processing unit 1 a and the processing of the post-processing unit 1 b to proceed asynchronously. Therefore, for example, the correction parameter and the main image data output from the pre-processing unit 1a can be temporarily stored in the image storage device 201. As a result, the stored original image data can be printed out at any time by performing document skew / size correction when necessary.

[Embodiment 3]
In this embodiment, a scanner-dedicated machine (image reading apparatus) provided with the document inclination / size detection unit 8 and the document inclination / size correction unit 9 according to the first embodiment will be described as an embodiment of the image forming apparatus according to the present invention. To do. FIG. 22 is a block diagram illustrating a configuration diagram of the scanner-dedicated device 300 according to the present embodiment. Note that devices or blocks having the same functions as those in Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 22, the scanner-dedicated device 300 includes a color image input device 3 and a color image processing device (image processing device) 301. The color image processing apparatus 301 includes an A / D conversion unit 5, a shading correction unit 6, an input tone correction unit 7, a document inclination / size detection unit 8, a document inclination / size correction unit 9, and a selector 302.

  When the original inclination / size correction function is selected in the scanner-dedicated device 300, the original inclination / size detection unit 8 detects the edge coordinates from the pre-image data obtained by the pre-scan as described above, and the correction parameter (Tilt angle α, corrected document size, correction processing start coordinates) are calculated. Further, the main image data after the input gradation correction is temporarily written in the image memory 16. Thereafter, the document inclination / size correction unit 9 reads the main image data and the correction parameters from the image memory 16, performs document inclination / size correction processing, and writes them again in the image memory 16. After the document inclination / size correction is completed for the image of one page, a control unit (not shown) reads the main image data after the inclination / size correction from the image memory 16 and sends it to the image storage device 301.

  On the other hand, when the original skew / size correction function is not selected as a special function, the main image data after the input gradation processing correction is sent to the image storage device 303.

  Here, the selector 302 has a function of switching data to be sent to the image storage device 303 between the main image data after the input gradation correction and the main image data after the document inclination / size correction processing. .

  In addition, data after tilt / size correction is not sent to the image storage device 303, but is sent to a computer, server, digital multifunction peripheral, printer, etc. connected to the scanner dedicated device 300 via a network. good. The document skew / size correction function may be selected from an operation panel of the scanner-dedicated machine 300 (not shown), or may be displayed on a scanner driver setting screen of the computer (reading condition setting screen of the scanner-dedicated device 300). It may be performed using a mouse or a keyboard.

[Embodiment 4]
As an embodiment of the present invention, a program code (execution format program, intermediate code program, source) for causing a computer to execute the above-described image processing method for determining the inclination / size of a document and performing rotation processing on the document. Recorded on a computer-readable recording medium recording a program). As a result, it is possible to provide a portable recording medium on which a program for performing an image processing method for determining the inclination / size of the original and performing rotation processing on the original is recorded.

  In the present embodiment, as the recording medium, a memory (for example, ROM) which is not shown may be a program medium because processing is performed by a microcomputer. Further, although not shown, a program reading device may be provided as an external storage device, and a program medium that can be read by inserting a recording medium therein may be used.

  In any case, the stored program code may be configured to be accessed and executed by a microprocessor, or in any case, the program code is read and the read program code is a microcomputer. The program code may be downloaded to a program storage area (not shown) and executed. It is assumed that this download program is stored in the main device in advance.

  Here, the program medium is a recording medium configured to be separable from the main body, such as a tape system such as a magnetic tape or a cassette tape, a magnetic disk such as a flexible disk or a hard disk, a CD-ROM / MO / MD / DVD, or the like. Semiconductors such as optical discs, IC cards (including memory cards) / optical cards, etc., or mask ROM, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), flash ROM, etc. It may be a medium that carries a fixed program code including a memory.

  In the present embodiment, since the system configuration is capable of connecting to a communication network including the Internet, the medium may be a medium that dynamically carries the program code so as to download the program code from the communication network. When the program code is downloaded from the communication network in this way, the program for downloading may be stored in the main device in advance or may be installed from another recording medium.

  The recording medium is read by a program reading device provided in a digital color image forming apparatus or a computer system, whereby the above-described image processing method is executed. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The computer system includes an image input device such as a flatbed scanner, a film scanner, and a digital camera, a computer that performs various processes such as the above image processing method by loading a predetermined program, and a CRT display that displays the processing results of the computer. An image display device such as a liquid crystal display and a printer that outputs the processing results of the computer to paper or the like. Furthermore, a network card, a modem, and the like are provided as communication means for connecting to a server or the like via a network.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the embodiments can be obtained by appropriately combining the respective technical means disclosed in the above-described embodiments. The form is also included in the technical scope of the present invention.

  The present invention can be applied to a copying machine, a multifunction machine, a scanner and the like having an image processing function.

1 is a block diagram showing a schematic configuration of a digital color copying machine according to a first embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an internal configuration of an image input apparatus provided in the digital color copying machine. FIG. 2 is a block diagram illustrating a schematic configuration of a document inclination / size detection unit provided in the color image processing apparatus. It is explanatory drawing which detects an edge from the pre image data containing the original document inclined. 4 is a table showing the correspondence between the values of tan θ and tan α and the values of θ and α. It is a figure which shows an example of a paper size table. It is explanatory drawing which shows an affine transformation. It is the flowchart which showed the user's operation procedure and the flow of processing of the digital color copying machine. (A) is a side view of the image input apparatus when the angle formed by the document table and the document cover is γ, and (b) is a diagram showing a scanned image scanned at (a). (A) is a side view of the image input apparatus when the document cover is closed, and (b) is a diagram showing a scanned image scanned at the time of (a). 6 is a flowchart showing a flow of processing of an upper document skew / size correction unit. 2A and 2B are schematic views showing a linear encoder for detecting an angle formed between a document table and a document cover, in which FIG. 1A shows the state of the linear encoder when the document cover is fully open, and FIG. FIG. 4C shows the state of the linear encoder when the angle between the document cover and the document cover is γ, and FIG. 8C shows the state of the linear encoder when the document cover is completely closed. (A) is a top view of the photosensor and actuator provided in the linear encoder of FIG. 12, (b) is a front view of the photosensor and actuator of (a), and (c) is the photo of (a). It is a side view of a sensor and an actuator. It is a chart which shows the waveform of the output signal of the photosensor with which the linear encoder of FIG. 12 is equipped. 2A and 2B are schematic diagrams showing an optical rotary encoder, in which FIG. 1A shows the state of the rotary encoder when the document cover is fully open, and FIG. 2B shows the angle formed between the document table and the document cover; (C) is a diagram showing the state of the rotary encoder when the document cover is completely closed. It is the figure which projected the rotary encoder from the arrow direction shown by FIG.15 (c). It is a chart which shows the waveform of the output signal of the photosensor with which the rotary encoder of FIG. 15 is equipped. It is a figure which shows the screen for making a user select various menus of a special function. FIG. 10 is a diagram showing a screen for allowing a user to select a setting state of a document skew / size correction function. FIG. 6 is a diagram illustrating a screen that allows a user to select whether or not a use guide for document skew / size correction is necessary. It is a block diagram which shows the digital color copying machine which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the scanner dedicated machine which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

1,1 'color image processing device (image processing device)
DESCRIPTION OF SYMBOLS 1a First stage processing part 1b Second stage processing part 2 Digital color copying machine (image reading apparatus, image forming apparatus)
3 Color image input device (document reading unit)
4 Color Image Output Device 8 Document Tilt / Size Detection Unit 9 Document Tilt / Size Correction Unit 16 Image Memory 81 Edge Detection Processing Unit 82 Parameter Calculation Unit 83 Determination Unit 120 Linear Encoder (Detection Unit)
122,123 Photosensor 150 Rotary encoder (detection unit)
152,153 Photosensor 300 Scanner dedicated machine (image reading device)
510 Upper housing (document cover)
561 Document table 562, 563 Scanning unit 565 CCD line sensor

Claims (10)

A document table, and a document cover that can be opened and closed with respect to the document table for covering the document placed on the document placement surface of the document table, and reads the document placed on the document placement surface When the angle formed between the document placement surface of the document reading unit that performs the above and the surface of the document cover facing the document placement surface is a first angle greater than 0, the document reading unit An original inclination / size detection unit for detecting an inclination angle of the original with respect to the scanning direction or sub-scanning direction of the reading and a size of the original, from the first image data obtained by starting reading;
With respect to the second image data obtained when the document reading unit starts reading the document after the document cover is closed, based on the detection result of the document inclination / size detection unit, the angle of the document and the document A document skew / size correction unit for correcting the size,
An image processing apparatus comprising: An image processing apparatus according to claim 1;
The document table having the document table, the document cover, and a document output unit that reads the document and outputs image data;
An image reading apparatus comprising: The document reading unit includes a detection unit that detects an angle formed between the document placement surface of the document table and a surface of the document cover facing the document placement surface,
The image reading unit according to claim 2, wherein the document reading unit starts the reading when an angle detected by the detection unit changes from an angle larger than the first angle to the first angle. apparatus.   The image reading apparatus according to claim 2, wherein the document reading unit receives a change of the first angle by a user.   The image reading apparatus according to claim 3, wherein the detection unit is an optical rotary encoder or an optical linear encoder.   Switching between a document tilt / size correction mode for operating the document tilt / size detection unit and the document tilt / size correction unit, and a non-correction mode for not operating the document tilt / size detection unit and the document tilt / size correction unit. The image reading apparatus according to claim 2, further comprising a mode control unit.   An image forming apparatus comprising the image reading apparatus according to claim 2. A document table, and a document cover that can be opened and closed with respect to the document table for covering the document placed on the document placement surface of the document table, and reads the document placed on the document placement surface When the angle formed between the document placement surface of the document reading unit that performs the above and the surface of the document cover facing the document placement surface is a first angle greater than 0, the document reading unit An original inclination / size detecting step for detecting an inclination angle of the original with respect to the scanning direction or the sub-scanning direction of the reading and the size of the original, from the first image data obtained by starting reading;
With respect to the second image data obtained when the document reading unit starts reading the document after the document cover is closed, the angle of the document is determined based on the detection result in the document inclination / size detection step. A document skew / size correction step for correcting the document size,
An image processing method comprising:   An image processing program for controlling the image processing apparatus according to claim 1, wherein the image processing program causes a computer to operate as each unit of the image processing apparatus.   A computer-readable recording medium on which the image processing program according to claim 9 is recorded.

Images