JP2006270387A - Image processor and method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor and a method and a program capable of correcting the inclination of a read original image at a higher speed. <P>SOLUTION: When an original is inclined and read in the case of a reading by an image-data reading section 101, starting-point coordinates and end-point coordinates are extracted at every main scanning line by an original discriminating section 102, and the movement (the quantity of a displacement) in the horizontal direction and the vertical direction is computed by a displacement detecting section 103 from the extracted starting-point coordinates and end-point coordinates. The inclination is corrected by shifting a movement section in the horizontal direction and the vertical direction respectively by an inclination correcting section 104 on the basis of the computed movement (the quantity of the displacement). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, method, and program for performing image processing on image data read using an image reading apparatus such as a scanner, and more particularly to an image processing apparatus, method, and method capable of correcting an image inclination. Regarding the program.

  In general, in the process of forming image data of an original image using an image reading device such as a scanner, image data as image data is generated by arranging and reading the original image at a predetermined base point. . Designating one of the four corners as the position designated as the base point at this time occupies the majority. This is because, by using the four corners as base points, the vertical and horizontal sides of the printed document image can be easily arranged horizontally and vertically with respect to the reading surface.

  However, a slight misplacement or static electricity may cause the document image to be misaligned. In this case, the image data of the generated image data is created obliquely, and in some cases, a part of the document image is generated. May not be able to be read.

  For this reason, the document image read by the scanner or the like may be difficult to see image data different from the user's desired image.

In the prior art disclosed in Patent Document 1, the inclination angle of an image is detected easily and quickly by comparing the range in which the original image is present on a plurality of scanning lines and detecting the inclination of the image. In addition, this prior art also makes it possible to correct the inclination of the image according to the detected inclination angle.
JP 05-274475

  However, in the prior art disclosed in Patent Document 1, it is necessary to store the corrected image data again in the memory area when correcting the inclination of the read image data. There is a problem that this results in an increase in memory as a system. Furthermore, there is a problem that processing time is increased due to re-storage in the memory area.

  SUMMARY An advantage of some aspects of the invention is that it provides an image processing apparatus, method, and program capable of correcting the inclination of a read original image at higher speed.

  In order to achieve the above object, according to a first aspect of the present invention, in an image processing apparatus for processing image data obtained by reading an original image with an image reading apparatus, the image data is identified for each scanning line. Then, a document identifying means for extracting the start point coordinates and the end point coordinates of the document image portion, and a shift amount in the main scanning direction is calculated from the start point coordinates and the end point coordinates of the document image portion extracted by the document identifying means. A first shift amount calculation unit; a second shift amount calculation unit that calculates a shift amount in the sub-scanning direction from a start point coordinate and an end point coordinate of the document image portion extracted by the document identification unit; and the first shift amount. The inclination of the document portion in the image data is corrected by correcting the position of each pixel from the amount of deviation in the main scanning direction by the amount calculating means and the amount of deviation in the sub-scanning direction by the second deviation amount calculating means. Characterized by comprising a tilt correction means.

  According to a second aspect of the present invention, in the first aspect of the invention, the tilt correction unit is configured such that the start point coordinate and the end point coordinate of the shift amount in the main scanning direction calculated by the first shift amount calculation unit are the same at first. The tilt correction is performed using the scanning line in the sub-scanning direction as the start coordinate of the document portion in the sub-scanning direction.

  According to a third aspect of the present invention, in the image processing method for processing image data obtained by reading an original image with an image reading apparatus, the image data is identified for each scanning line, and the original image portion is identified. The starting point coordinates and the end point coordinates of the part are extracted by the document identifying means, and the shift amount in the main scanning direction is calculated by the first shift amount calculating means from the start point coordinates and the end point coordinates of the document image portion extracted by the document identifying means. The amount of deviation in the sub-scanning direction is calculated by the second amount of deviation calculating means from the start point coordinates and the end point coordinates of the original image portion calculated and extracted by the original identifying means, and the main amount by the first amount of deviation calculating means is calculated. The inclination of the document portion in the image data is corrected by correcting the position of each pixel from the amount of deviation in the scanning direction and the amount of deviation in the sub-scanning direction by the second deviation amount calculating means.

  According to a fourth aspect of the present invention, there is provided an image processing program for performing processing of image data obtained by reading an original image with an image reading apparatus using a computer, wherein the image data is converted into the original image portion for each scanning line. A first step of identifying and extracting a start point coordinate and an end point coordinate of the document image portion; and a deviation amount in the main scanning direction from the start point coordinate and the end point coordinate of the document image portion extracted by the first step. A second step of calculating, a third step of calculating a shift amount in the sub-scanning direction from the start point coordinates and the end point coordinates of the document image portion extracted in the first step, and a main step of the second step. A fourth scan for correcting the inclination of the document portion in the image data by correcting the position of each pixel from the shift amount in the scanning direction and the shift amount in the sub-scanning direction in the third step. Tsu, characterized in that it comprises a flop.

  According to the present invention, a document portion of image data read by using an image reading device such as a scanner is identified for each scanning line, and the coordinates of the start point and end point of the document portion are extracted, so that the main scanning direction and sub-scanning are performed. Since the document skew correction is performed by calculating the amount of deviation in both directions, it is possible to correct the document skew for the read image data, so the time required for memory read / write can be omitted. As a result, the tilt correction can be performed at a higher speed.

  Hereinafter, an image processing apparatus, method, and program according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an apparatus configuration diagram of an image processing apparatus configured by applying an image processing apparatus, method and program according to the present invention.

  In FIG. 1, the image processing apparatus includes an image data reading unit 101, a document identification unit 102, a deviation detection unit 103, an inclination correction unit 104, an image memory 105, and an output unit 106. The inclination correction unit 104 corrects the inclination of the image data read in step S, and the corrected image data is output by the output unit 106.

  The image data reading unit 101 includes a CCD (Charge Coupled Device) or the like, and forms image data by reading a document. The read image data is stored in the line buffer for each scanning line (line).

  The document identification unit 102 identifies the document part of the image data read by the image data reading unit 101. The read image data is provided with margins that are margins on the top, bottom, left, and right, and a document portion that is a portion other than the margin is identified. In particular, when the original portion of the read image data is read in an inclined state, the original portion and the non-original portion are identified for each main scanning line.

  At this time, when the document portion is identified, the start point coordinates and end point coordinates of the document portion are extracted for each main scanning line, and the extracted start point coordinates and end point coordinates are stored in the register for each main scanning line. For example, “start point coordinate: 17” and “end point coordinate: 19” of the second main scanning line are stored.

  The deviation detection unit 103 is based on the start point coordinate and the end point coordinate of the document part identified by the document identification unit 102, and is moved in the horizontal direction (main scanning line direction) and the vertical direction (sub-scanning line direction) (hereinafter referred to as “deviation”). (Also referred to as “quantity”).

  An example of calculating the horizontal movement amount X, which is the horizontal movement amount at this time, and the vertical movement amount Y, which is the vertical movement amount, is shown in FIG.

  The inclination correction unit 104 holds a line buffer that temporarily stores the image data read by the image data reading unit 101, and is detected by the deviation detection unit 103 with respect to the image data stored in the line buffer. Based on the horizontal movement amount X and the vertical movement amount Y, the inclination of the entire image data is corrected by shifting each movement direction by the movement amount.

  That is, the inclination correction is performed for each scanning line (line) in the main scanning line direction, and is stored as image data in the image memory 105 for each corrected line.

  The image memory 105 is configured by a RAM (Random Access Memory) or the like, stores image data corrected by the inclination correction unit 104 for the image data read by the image data reading unit 101 for each line, and for all lines. This is a storage area for storing the corrected image data.

  The output unit 106 outputs the image data after tilt correction stored in the image memory 105. For example, it is possible to output to a host device such as a client PC connected via a network line.

  According to such a configuration, when the document is read while being tilted by the image data reading unit 101, the document identification unit 102 extracts the start point coordinates and the end point coordinates for each main scanning line, and the extracted start point coordinates and A displacement detection unit 103 calculates a movement amount (deviation amount) between the horizontal direction and the vertical direction from the end point coordinates. Then, the inclination correction can be performed by shifting the movement amount in the horizontal direction and the vertical direction by the inclination correction unit 104 based on the calculated movement amount (deviation amount).

  FIG. 2 is a flowchart showing a flow of processing of the document identifying unit shown in FIG.

  In FIG. 2, when the user sets a document to be read in the image data reading unit and instructs to start reading, the process is started, the document is read (S201), and the initialization process (FE flag is set to “0”). Is set to “zero)”) (S202). Document reading is performed for each line in the main scanning direction.

  A document portion outline reading process for identifying a document portion and a non-document portion is performed for one line in the main scanning direction read (S203). If all the lines are non-original parts, it is identified that there is no original part on that line. On the other hand, when the document portion is identified even with one pixel, the start point coordinates and end point coordinates of the identified document portion are extracted.

  It is determined whether all of one line is a non-original part (S204), and when at least one pixel and an original part are identified (NO in S204), the start point coordinates and end point coordinates of the identified original part are determined in the main scanning direction. A coordinate storing process for storing in the register for each line is performed (S205). Then, the FE flag that has been initialized in response to the identification of the document portion is updated from “0 (zero)” to “1” (S206).

  In response to the completion of the update of the FE flag or the fact that all lines in the main scanning direction are non-original portions (YES in S204), it is determined whether the FE flag is “0 (zero)” (S207). That is, if all lines are non-original parts, the FE flag is “0 (zero)”, and if at least one pixel is identified, the FE flag is “1”. .

  If the FE flag is “0 (zero)” (YES in S207), the document part contour reading process 203 is repeated again. If the FE flag is not “0 (zero)” (NO in S207), it is subsequently determined whether the above processing has been executed for all lines (S208), and is executed for all lines. If there is not (NO in S208), the document part outline reading process 203 is similarly repeated. If all lines have been executed, the process is terminated.

  As a result, it is possible to discriminate between the original portion and the non-original portion with respect to the read image data. When the original portion is identified, the start point coordinates and the end point coordinates are stored in the register for each scanning line in the main scanning direction. can do.

  FIG. 3 is a flowchart showing a flow of processing of the deviation detecting unit and the inclination correcting unit shown in FIG.

  In FIG. 3, the process starts when the document identification unit identifies the document part and the non-document part, and the document identification unit moves in the vertical direction from the start point coordinates and the end point coordinates stored in the register in the register. An amount (vertical movement amount: Y) and a horizontal movement amount (horizontal movement amount: X) are calculated (S301), and it is determined whether there is a vertical movement amount Y (S302). If there is a movement amount (YES in S302), the image data read by the image data reading unit is acquired for each line from the line buffer in which the image data is temporarily stored, and the calculated vertical movement amount Y And the horizontal movement amount X to correct the tilt by shifting the pixels, and simultaneously output the image data to the image memory.

  If the vertical movement amount Y does not exist (NO in S302), it is determined that there is no inclination of the image data, and the process ends.

  Thereby, it is possible to calculate the movement amount (deviation amount) for each main scanning line of the image data read in a tilted state, and to perform tilt correction based on this.

  FIG. 4 is a diagram illustrating a specific calculation example of the vertical movement amount and the horizontal movement amount by the deviation detection unit.

  FIG. 4 shows image data in a state of being read by the image data reading unit. In the drawing shown here, an example in which the right shoulder of the document is read at a position higher than the left shoulder is shown.

  In this image data, the starting point coordinates and the ending point coordinates for each scanning line identified as the document part by the document identifying part 102 are as follows.

In the first line, since the original part is not identified, neither the start point coordinates nor the end point coordinates exist. The second line has start point coordinates: 17 and end point coordinates: 19
The third line has a start point coordinate: 11 and an end point coordinate: 19
The fourth line has a start point coordinate of 5 and an end point coordinate of 19
The fifth line has start point coordinates: 2, end point coordinates: 20
The 6th line has start point coordinates: 2, end point coordinates: 20
The seventh line has a start point coordinate: 2 and an end point coordinate: 20.
On the 8th line, start point coordinate: 3, end point coordinate: 20
The starting point coordinates and the ending point coordinates of the fifth line and the sixth line are equal to each other based on the information on the starting point coordinates and the ending point coordinates of the original portion described above. Therefore, the fifth line is set as the vertical reference. This is because the horizontal shift amount of each line again occurs after the start point coordinate and the end point coordinate are once the same value.

  That is, the vertical deviation amount Y of the entire original read by the information from the second line to the fifth line is calculated, and the horizontal deviation amount X is sequentially calculated from the fifth line onward. Become. In the example shown here, the amount of deviation in the horizontal direction at the eighth line is “1”.

  The vertical displacement amount Y can be calculated when the image data is read up to the sixth line, and the horizontal displacement amount X is calculated when the original line is read to the last line. can do.

The amount of deviation calculated by this is
The first line is misalignment amount Y: 0, misalignment amount X: 0
The second line is misalignment amount Y: 0, misalignment amount X: 0
The third line is misalignment amount Y: 1, misalignment amount X: 0
The fourth line is misalignment amount Y: 2, misalignment amount X: 0
The fifth line is misalignment amount Y: 3, misalignment amount X: 0
The sixth line is misalignment amount Y: 3, misalignment amount X: 0
The seventh line is misalignment amount Y: 3, misalignment amount X: 0
Eighth line is misalignment amount Y: 3, misalignment amount X: 1
It becomes. The deviation amount X from the first line to the fourth line is “0 (zero)” because it is the reading stage before the fifth line as a reference. Further, the shift amount X of the sixth line, which is based on the fifth line and has the same start point coordinates and end point coordinates as the fifth line, is “0 (zero)”. Further, since the start point coordinates and the end point coordinates of the seventh line are the same as those of the fifth and sixth lines, the deviation amount X is similarly “0 (zero)”.

  Then, since the start point coordinate at the 8th line is “3” which is shifted by 1 from the start point coordinate “2” at the 5th line, the shift amount X at the 8th line is calculated as “1”. it can.

  When tilt correction is performed by shifting the amount of movement in the vertical and horizontal directions (deviation amount Y, deviation amount X) by the amount of movement, the following results.

First, there is no image data pixel from the first line to the fourth line.

Next, on the fifth line, the pixels on the second line from coordinates 17 to 19; the third line on the coordinates from 11 to 16; the fourth line on the coordinates from 5 to 10; the fifth line on the coordinates from 2 to 4 Is masked. At this time, since the horizontal shift amount X is “0 (zero)”, the shift in the horizontal direction is not performed.

In the sixth line, pixels 17 to 19 on the third line, pixels 11 to 16 on the fourth line, pixels 5 to 10 on the fifth line, and pixels 2 to 4 on the sixth line. Masked. At this time as well, the horizontal shift amount X is “0 (zero)”, so the shift in the horizontal direction is not performed.

  Similarly, when processing is performed for each scanning line in the main scanning direction, the image data is corrected as shown in FIG.

  FIG. 5 is a flowchart showing a flow of processing of the inclination correction unit shown in FIG.

  In FIG. 5, when the displacement detection unit calculates the vertical movement amount and the horizontal movement amount, it is determined whether or not the calculated vertical movement amount exists (the vertical movement amount is zero) (S501). If it does not exist (YES in S501), the process ends. If there is a vertical movement amount (NO in S501), it is assumed that there is an inclination in the read image data, and the vertical inclination is shifted for each line based on the vertical movement amount Y calculated by the deviation detection unit. Correction processing is performed (S502).

  Next, it is determined whether the calculated horizontal movement amount does not exist (the horizontal movement amount is zero) (S503). If there is no horizontal movement amount (YES in S503), the vertical movement with respect to the next line is determined. An inclination correction process (S502) is performed.

  If there is a horizontal movement amount (NO in S503), a horizontal inclination correction process is performed to shift line by line based on the horizontal movement amount X calculated by the shift detection unit (S504).

  As a result, the document portion is shifted in both the horizontal direction and the vertical direction, and the inclination is corrected.

  FIG. 6 is a diagram showing corrected image data obtained by performing tilt correction on the read image data shown in FIG.

  In FIG. 6, correction is performed as follows for each line shown in FIG.

1st to 4th lines in the main scanning direction:
No image data 5th line in the main scanning direction:
2nd to 4th lines in the sub-scanning direction of the 5th line in the main scanning direction
4th line in the main scanning direction 5th to 10th lines in the sub scanning direction
11th to 16th lines in the sub-scanning direction in the 3rd line in the main scanning direction
17th to 19th lines in the sub-scanning direction of the second line in the main scanning direction 6th line in the main scanning direction:
6th line in the main scanning direction 2nd to 4th lines in the sub-scanning direction
5th to 10th lines in the sub-scanning direction of the 5th line in the main scanning direction
11th to 16th lines in the sub-scanning direction of the 4th line in the main scanning direction
17th to 19th lines in the sub-scanning direction of the 3rd line in the main scanning direction 7th line in the main scanning direction:
7th line in the main scanning direction 2nd to 4th lines in the sub-scanning direction
5th to 10th lines in the sub-scanning direction of the 6th line in the main scanning direction
11th to 16th lines in the sub-scanning direction of the fifth line in the main scanning direction
4th line in the main scanning direction 17th to 19th lines in the sub scanning direction 8th line in the main scanning direction:
8th line in the main scanning direction 3rd to 4th lines in the sub-scanning direction
5th to 10th lines in the sub-scanning direction of the 7th line in the main scanning direction
11th to 16th lines in the sub-scanning direction of the 6th line in the main scanning direction
Thus, the image data in which the tilt correction is performed in both the main scanning direction and the sub-scanning direction can be formed.

  Through the above processing, the image processing apparatus of the present invention can correct the tilt of the read image data even when the read image data is tilted.

  Further, tilt correction can be performed during storage in the image memory.

  Therefore, by applying the present invention, it is possible to expect an effect that the tilt correction can be performed at a higher speed since the read / write processing related to the detection of the tilt angle and the read / write of the memory becomes unnecessary.

  Further, it is possible to output image data having no inclination in a short time.

  The processing shown in the flowchart can also be realized by an image processing program that can be executed by a computer.

  The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not changing the gist thereof.

  The present invention can be applied to an image processing apparatus, method, and program for correcting the inclination of image data read using an image reading apparatus such as a scanner, and in particular, correcting the inclination of a document portion of image data at higher speed. Useful for.

1 is a block diagram of an image processing apparatus configured by applying an image processing apparatus, method and program according to the present invention. 3 is a flowchart showing a flow of processing of a document identification unit shown in FIG. The flowchart which shows the flow of a process of the deviation detection part and inclination correction | amendment part which are shown in FIG. The figure which shows the image data read in the state in which the original document inclined by the image data reading part. The flowchart which shows the flow of a process of the inclination correction | amendment part shown in FIG. The figure which shows the image data after correction which performed inclination correction with respect to the read image data shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Image data reading part 102 Document identification part 103 Displacement detection part 104 Inclination correction part 105 Image memory 106 Output part

Claims (4)

In an image processing apparatus that processes image data obtained by reading a document image with an image reading apparatus,
Document identifying means for identifying the document image portion of the image data for each scanning line and extracting the start point coordinates and the end point coordinates of the document image portion;
First shift amount calculation means for calculating a shift amount in the main scanning direction from the start point coordinates and end point coordinates of the document image portion extracted by the document identification means;
Second displacement amount calculating means for calculating a displacement amount in the sub-scanning direction from the start point coordinates and the end point coordinates of the document image portion extracted by the document identifying means;
By correcting the position of each pixel from the shift amount in the main scanning direction by the first shift amount calculating unit and the shift amount in the sub-scanning direction by the second shift amount calculating unit, the inclination of the document portion in the image data is corrected. An image processing apparatus comprising: an inclination correction unit for correcting. The inclination correction means includes
Inclination correction is performed by using a scanning line in the sub-scanning direction in which the start point coordinate and the end point coordinate of the shift amount in the main scanning direction calculated by the first shift amount calculating unit are the same as the start coordinates of the original portion in the sub-scanning direction. The image processing apparatus according to claim 1, wherein: In an image processing method for processing image data obtained by reading an original image with an image reading device,
Identifying the original image portion of the image data for each scanning line, and extracting the start point coordinates and the end point coordinates of the original image portion by an original identification means;
A first shift amount calculating unit calculates a shift amount in a main scanning direction from a start point coordinate and an end point coordinate of the document image portion extracted by the document identification unit;
A second shift amount calculating unit calculates a shift amount in the sub-scanning direction from a start point coordinate and an end point coordinate of the document image portion extracted by the document identifying unit;
By correcting the position of each pixel from the shift amount in the main scanning direction by the first shift amount calculating unit and the shift amount in the sub-scanning direction by the second shift amount calculating unit, the inclination of the document portion in the image data is corrected. An image processing method characterized by correcting. An image processing program that uses a computer to process image data obtained by reading a document image with an image reading device,
A first step of identifying the original image portion of the image data for each scanning line, and extracting a start point coordinate and an end point coordinate of the original image portion;
A second step of calculating a shift amount in the main scanning direction from a start point coordinate and an end point coordinate of the document image portion extracted in the first step;
A third step of calculating a shift amount in the sub-scanning direction from a start point coordinate and an end point coordinate of the document image portion extracted in the first step;
Fourth step of correcting the inclination of the document portion in the image data by correcting the position of each pixel from the amount of deviation in the main scanning direction by the second step and the amount of deviation in the sub-scanning direction by the third step. An image processing program comprising:

Images