JP2551383B2 - Straight line detection and correction device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a straight line detection / correction device, and more particularly to a correction device for removing and restoring distortion of straight line data read by a scanner or the like.

[0002]

2. Description of the Related Art FIGS. 10 and 11 show the contents disclosed in, for example, Japanese Patent Publication No. 3-46044, which is presented as a conventional example.

As shown in FIG. 10, a conventional straight line detecting apparatus includes a binarization circuit 12 for converting a pattern read by scanning with a photoelectric conversion scanner 11 into a binary image of "0" and "1". , A window generation circuit 13 for setting a detection area in the image pickup area of the photoelectric conversion scanner 11, an area division circuit 14 for equally dividing the detection area into two horizontal areas, and in each divided area Area count circuit 15 that counts the number of binarized values "1" up to the pattern edge, and each counted area is divided by the width of each divided area to calculate the pattern edge position. And a straight line detection circuit 16 for detecting the straight line.

Next, the operation will be described with reference to FIG.

Imaging area 100 converted into a binary image
The inspection area 101 is provided by the window generation circuit 13
Is set, and this area is equally divided into two horizontal areas 102 by the area dividing circuit 14. The area count circuit 15 counts the number of binarized values “1” in each of the divided horizontal areas up to the pattern edge 103. The arrow in the area count area 104 indicates the count value.

The count value is divided by the width of the divided area to calculate the edge position 105. That is, the area count area is approximated by the area of the trapezoid, and the center position of the trapezoid side becomes the edge position 105.

An approximate straight line 106 is obtained from the coordinates of the two points at the edge position 105.

[0008]

However, in the above-described conventional straight line detecting device, it is necessary to take a large area of the window for inspecting the straight line data, and it takes a long time to search.

Further, it is difficult to judge whether the line is a straight line because only one side of the image data is detected.

The present invention has been made in view of the above-mentioned conventional circumstances, and therefore an object of the present invention is to provide a novel straight line detection / correction device capable of solving the above-mentioned problems inherent in the prior art. To do.

[0011]

In order to achieve the above object, a straight line detection / correction apparatus according to the present invention is provided with "0" and "1".
Image drawing data storage section for holding data imaged from the binary data, drawing data reading means for reading data from the image drawing data storage section, and straight line data from the data read by the drawing data reading means. A straight line data search means for searching for, a straight line pattern information storage section for holding pattern information such as position and width of the straight line data, and a correction data writing means for writing the corrected data in the data storage section before the straight line correction, A straight line approximation correction control unit that controls the drawing data reading unit, the straight line data searching unit, and the correction data writing unit and performs a straight line approximation correction process based on the straight line pattern information, and a correction execution range such as a width of a straight line for which correction is effective And a correction range instruction input unit.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be specifically described with reference to the drawings with respect to a preferred embodiment thereof.

FIG. 1 is a block diagram showing an embodiment of the present invention.

Referring to FIG. 1, a document containing straight line data is scanned by the scanner read image data input unit 8 and transferred to the image data processing / drawing control unit 9 as multivalued or binary information.

The image data processing / drawing control section 9 performs image processing based on multivalued or binary information, and generates image data which can be output to the output device 10 as binary data of "0" and "1". The image data is stored in the image drawing data storage unit 1.

Due to the resolution of the scanner or the inclination of the document with respect to the scanning direction for scanning the data, the straight line data scanned by the scanner may contain distortion or have non-uniform line widths. Hereinafter, a means for detecting and correcting straight line data from the image data in the data storage unit 1 will be described.

The drawing reading means 3 reads data from the drawing data storage section 1 under the control of the linear approximation correction control section 2. The data size to be read is defined by an l × m matrix consisting of vertical 1 pixel and horizontal m pixels. 2 to 5,
As an example, a case where data is searched using an 8 × 8 matrix with l = 8 and m = 8 is shown.

In FIG. 2, a (x, y) means a bit address of drawing data in a unit of one pixel in the data storage unit 1, x indicates a horizontal address coordinate, and y indicates a vertical address coordinate. ing. The straight line data search means 4 searches whether the data read by the drawing data reading means 3 in the 8 × 8 matrix window contains information that is presumed to be straight line data. FIG. 3 is an enlarged view of the part a (x, y) -a (x + 8, y + 8) in FIG.

As shown in FIG. 3, the straight line data retrieval means 4 presumes a straight line in the case where a continuous pattern exists in a window of 8 × 8 matrix and the window is divided into two. Whether or not the data is continuous is determined when black data (information “1”) exists in line 0 of FIG. 3, that is, when black (“1”) exists in a (x + 4, y). , Line 1 a (x + 3, y + 1), a
It is searched whether or not black data (information “1”) exists in (x + 4, y + 1) and a (x + 5, y + 1).

Similarly, the continuity can be confirmed by confirming the existence of data in the vicinity of lines 2 to 7. At the same time, the line information is 8 as shown in FIG.
In the window of × 8 matrix, black data (information “1”) exists from which address for each line,
The number of pixels of the black data width is searched. These pieces of information are held in the straight line pattern information storage unit 5.

The linear approximation correction control unit 2 calculates the slope of the continuity of a straight line as shown in FIG. 5 from the straight line pattern information shown in FIG. In the straight line data in FIG. 3, y
A linear function of = -2x is expected.

Here, in order to improve the confirmation of the straight line, the information of another window following the window just searched is searched. Already a (x, y) -a (x + 8, y + 8)
Since the data is confirmed in the window of
From (x, y) as a base point, a (x-
A (x-4, y + 8) -a based on 4, y + 8)
The information in the window (x + 4, y + 16) is searched.

From FIG. 2, a (x-4, y + 8) -a (x +
The pattern in (4, y + 16) is a (x, y) -a (x
It can be seen that they are continuous from +8, y + 8).
This operation is repeated until the start and end points of the continuous pattern are confirmed.

From the same information as that shown in FIG. 4 obtained from a plurality of 8 × 8 matrix windows, a linear repeating pattern of a normal pattern can be inferred.

That is, in the pattern shown in FIG. 3, three blacks ("1") are drawn in the positive direction of y, then one is shifted in the negative direction of x, and three blacks ("1") in the positive direction of y. It is judged that the pattern for drawing ") is desirable. The correction pattern obtained by this estimation is shown in FIG.

Based on the correction pattern information shown in FIG. 6, the linear approximation correction control unit 2 causes the correction data writing unit 6 to replace the original image data in the image drawing data storage unit 1 with the corrected data.

The correction range instruction input unit 7 can set conditions for the range to be corrected. That is, by setting the lowest line of the number of continuous data pixels, the correction is not applied to the straight line data that is less than the number of pixels. As a result, it becomes possible not to perform the correction process on the straight line of the character or the like.

If the above description is expressed by an operation flow, FIG.
become that way.

In FIG. 7, when 1 × m matrix is used, α1 is an integer multiple of l, and β1 is an integer multiple of m.

The conditions for the straight line data are that the data is continuous within the window and that the window is divided into two.

Α2 and β2 are calculated by a linear function formula.

The straight line data search means 4 and the straight line approximation correction control unit 2 in the configuration diagram of the present invention shown in FIG. 1 will be described in detail with reference to the detailed block diagrams of FIGS. 8 and 9.

In FIG. 8, the straight line data retrieval means 4 reads 8 × 8 read by the drawing data reading means 3.
The black information recognition means 42 searches for whether or not straight line data exists in the window of the matrix. When the presence of black information is recognized in the nth line, it is determined whether or not there is continuous data in the subsequent (n + 1) th line.

The bit address adder / subtractor 43 a (v-1, w + 1), a on the (n + 1) th line adjacent to the address coordinate a (v, w) of the black information recognized on the nth line.
This is means for obtaining the coordinates of (v, w + 1) and a (v + 1, w + 1).

The (n + 1) th line linear correlation discriminating unit 44 discriminates whether or not black information exists in the address coordinate portion calculated by the bit address adder / subtractor 43 and discriminates the linear continuity of the data.

In FIG. 9, the linear approximation correction control unit 2 is
If the straight line continuity of the black data is recognized by the straight line data searching means 4, the straight line correction control is performed on the original data based on the information on the straight line pattern recognition. The correction procedure is shown below.

The drawing data reading means control unit 21 controls the reading of the data to be corrected in the image drawing data storage unit 1. The read data is corrected by taking the logical product with the pattern information in the straight line pattern information storage unit 5.

On the other hand, the straight line length counter 22 counts the length of the black data in dot units as the continuous information of the black data.

The correction range instruction input unit 7 sets the minimum value of the length of the black data to be corrected, and this minimum value is compared with the value of the straight line length counter 22 to determine whether or not the straight line correction can be performed. At 23, it is determined whether or not the correction is performed.

The data obtained based on the judgment of the straight line correction executability judging section 23 is stored in the newly generated data holding section 24, and the original data in the image drawing data storage section 1 is stored in the correction data writing means control section 25. Replaced with data.

The straight line inclination calculating unit 26 calculates a straight line inclination y =-(cos θ / sin θ) x as shown in FIG. 5 based on the straight line pattern output from the straight line pattern information storage unit 5.

The correction range instruction input section 7 can be composed of, for example, a control panel having a switch or the like.

[0043]

As described above, according to the present invention,
When straight line data is searched using the window of the specified matrix, it is possible to avoid wasting search time by inferring the function formula of the straight line and searching the data within the minimum range. The effect that the correction process becomes faster can be obtained.

Further, according to the present invention, since the target pixel is managed by the address, it is possible to obtain the effect that the data correction can be performed on a pixel-by-pixel basis.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a straight line data search method in an image drawing data storage unit.

FIG. 3 is an enlarged view in which a part of FIG. 2 is enlarged.

FIG. 4 is a diagram showing straight line pattern information in FIG.

FIG. 5 is a diagram showing a method of calculating a straight line functional expression calculated from FIG. 4;

FIG. 6 is a diagram showing straight line data after correction with respect to FIG.

FIG. 7 is a flowchart showing an operation flow of an embodiment according to the present invention.

FIG. 8 is a block diagram showing a specific example of a straight line data detecting means.

FIG. 9 is a block configuration diagram showing a specific example of a linear approximation correction control unit.

FIG. 10 is a configuration diagram of a conventional technique.

FIG. 11 is a diagram illustrating the principle of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image drawing data storage unit 2 ... Linear approximation correction control unit 3 ... Drawing data reading unit 4 ... Straight line data retrieval unit 5 ... Straight line pattern information storage unit 6 ... Correction data writing unit 7 ... Correction range instruction input unit 8 ... Scanner reading Image data input unit 9 ... Image data processing drawing control unit 10 ... Output device

Claims (5)

(57) [Claims] 1. An image drawing data storage unit for holding data imaged by binary data of "0" and "1", a drawing data reading unit for reading data from the image drawing data storage unit, and the drawing. Straight line data searching means for searching straight line data from the data read by the data reading means, straight line pattern information storage section for holding pattern information such as position and width of straight line data, and the image drawing data storage section before straight line correction Correction data writing means for writing the corrected data to the above, and a linear approximation correction control portion for controlling the drawing data reading means, the linear data retrieval means and the correction data writing means to perform linear approximation correction processing from linear pattern information. A straight line detection / correction device characterized by the above. 2. The straight line data searching means includes an nth line reading means for reading the nth line by the drawing data reading means and an nth line read by the nth line reading means.
Black information recognition means for recognizing black information in a line, bit address addition / subtraction means for outputting the address of the (n + 1) th line following the nth line, and black information in the address coordinate portion calculated by the bit address addition / subtraction means. The (n + 1) th discriminating whether or not it exists and discriminating the continuous straight line of the data
The line detection / correction apparatus according to claim 1, further comprising line line correlation identification means. 3. The linear approximation correction control unit, a drawing data read-out unit control unit for controlling reading of data to be corrected in the image drawing data storage unit, an output of the drawing data read-out unit control unit, and the straight line pattern information. A logical product means for taking a logical product with the output of the storage unit, a linear length counter for counting the length of black data in dot units as continuous information of black data, a count value of the linear length counter and a correction range instruction input unit Correction execution possibility determining means for comparing the minimum value of the length of the black data for performing the correction and determining whether the correction is performed based on the comparison result, and the logical product based on the determination result of the correction execution possibility determining means. The newly generated data holding means for storing the newly generated data obtained by operating the means, and the new data output from the new data holding means It is further characterized by having a correction data writing means control section for controlling replacement of the original data in the image drawing data storage section, and a straight line inclination calculation means for calculating the inclination of a straight line based on the information of the straight line pattern information storage section. The straight line detection / correction device according to claim 1. 4. The straight line detection / correction apparatus according to claim 1, further comprising a correction range instruction input unit that defines a correction execution range such as a length of a straight line that makes correction effective. . 5. The straight line approximation correction control unit further infers a function formula of a straight line from the straight line pattern information obtained by the straight line data searching means, and searches for data in the image drawing data storage unit. The straight line detection / correction device according to claim 1.