JP2626011B2 - Drawing reading processing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing reading processing method set in an apparatus that reads a handwritten drawing and performs image processing and drawing recognition processing. A graphic symbol that spans multiple blocks written on a fixed format drawing printed in color and divided into blocks by these ruled lines,
This is to improve the contact character separation processing.

<Conventional technology> A drawing reader for reading a fixed format drawing in which ruled lines and the like are printed in a dropout color and characters and symbols are written in blocks delimited by the ruled lines is read characters and symbols. It is necessary to determine how many rows and columns in the drawing correspond to the block.

FIG. 5 shows an example of a fixed format drawing to be read.

In the fixed format drawing D, the ruled line F and print characters "symbol" and "rule" are printed in a dropout color (a color ignored by an image scanner in the drawing reading apparatus), and divided into blocks B by the ruled line F Have been.

For example, it is assumed that the characters “Y” and “N” are written in blocks in the rule column by handwriting on such a drawing D.

The drawing entrant uses a horizontal line "-" (L) as a repetition symbol when the character "Y" continues five characters in the horizontal direction or saves the character "N" in the vertical direction by four characters in order to save the labor of entry.
When characters continue, a vertical bar "|" (L) is used as a repeat symbol.
May be used. In addition, there is a case where symbols at the top, bottom, left and right touch each other (contact character C).

In any case, these graphic symbols L and contact characters C extend over a plurality of blocks in the upper, lower, left, and right directions. Therefore, in order to position the characters and symbols written in one block, these connected graphics must be separated for each block. There must be.

In the conventional method of separating connected figures, a corresponding drawing is input as an image, its binary image data is stored in an image memory, and a virtual ruled line corresponding to a ruled line on the drawing is stored in this image memory with a pixel value " In this method, the image memory is divided into grids for each block to separate connected graphics. Here, on the image memory, the pixel value “1” is a figure portion, and the pixel value “0” is a background portion.

<Problem to be solved by the invention> However, the above-mentioned conventional disconnection method has the following problems.

That is, as shown in FIGS. 6 (a) and 6 (b), in order to draw a virtual ruled line G (dotted line) on the image memory corresponding to the ruled line F (solid line) on the drawing, one character ( (Or symbol) If the block slightly protrudes when writing “Y” or “N”, it is unnecessarily cut off as two characters, and it becomes impossible to recognize or cause erroneous recognition in the recognition process. The drawing process is a useless process if there is no repetitive graphic symbol (L or the like).

An object of the present invention is to solve the above two problems, and to draw graphic symbols and contact characters written on a fixed format drawing in which ruled lines and the like are printed in dropout color and divided into a plurality of blocks by the ruled lines. An object of the present invention is to realize a method of efficiently separating each block.

<Means for Solving the Problems> The present invention stops drawing virtual rules over the entire image memory, extracts a connected drawing on the image memory, and divides the drawing into a plurality of blocks based on the size of the circumscribed rectangle. Then, characters and symbols included in the connected figure are extracted by drawing an inner ruled line for dividing the plurality of blocks, and the specific processing procedure is as follows.

The present invention provides an image scanner that scans a fixed-format drawing in which each block is divided into blocks and characters and symbols are written in each block, an image memory that stores the obtained binary image data, and a control that controls the whole. And (b) setting a circumscribed rectangle in the extracted connected graphic by performing a raster scan of the image memory and extracting a connected graphic. (C) determining the position and size of the circumscribed rectangle and comparing the size of the circumscribed rectangle with a preset value; and (c) if the circumscribed rectangle is large in step (b), the coordinates of each vertex of the circumscribed rectangle. And (d) determining which block in the drawing contains the obtained coordinate value and determining a plurality of blocks over which the circumscribed rectangle extends. (E) determining an inner ruled line for mutually dividing the plurality of blocks determined in step (d) on the drawing, and a line having a pixel value “0” corresponding to the inner ruled line on the image memory. The drawing reading processing method is characterized in that the connected graphics are separated into blocks by executing the following steps:

<Operation> The drawing reading processing method of the present invention checks the size of a circumscribed rectangle of a connected figure in an image memory, and if the size is larger than a predetermined value, detects a block including the vertex on the drawing. A plurality of blocks spanning the circumscribed rectangle are detected, an inner ruled line is drawn with a pixel value “0” so as to divide the plurality of blocks, and a process of separating blocks of a connected figure is performed.

<Embodiment> FIG. 1 shows an apparatus for realizing the drawing reading processing method of the present invention.

The fixed format drawing D is scanned by the image scanner 1, and the read drawing information is stored in the image memory 2 as a binary converted image signal. Image memory 2
Is a portion for temporarily storing binary image data in which the figure portion has a pixel value of “1” and the background portion has a pixel value of “0” corresponding to FIG.

The control unit 3 is composed of a microprocessor or the like and controls the whole, and also performs a raster scan of the image memory 2,
A process of extracting a connected figure, a coordinate conversion process of making a coordinate point on the image memory 2 correspond to a coordinate point on the drawing D on a one-to-one basis,
This is a portion for executing the method of the present invention such as a line segment generation process for the image memory 2.

Such a configuration is the same as the configuration of the conventional drawing reading apparatus, but the present invention is characterized by the processing operation set in the control unit 3.

Also, the fixed format drawing to be read is
Drawing D in which connected figures such as repetitive figure symbols L and contact characters C as shown in FIG.
It is.

FIG. 2 is a flowchart showing a drawing reading method of the present invention set in the control section 3 of the apparatus shown in FIG.

According to this flowchart, the principle of the drawing reading processing method of the present invention will be schematically described.

Upon activation of the control unit 3, the image scanner 1 reads the standard format drawing D written by hand, and stores binary image data in the image memory 2 as drawing information.

The control unit 3 raster scans the image memory 2 and detects characters, symbols, repetitive graphic symbols (vertical lines, horizontal lines, etc.), and connected graphics such as contact characters.

When a connected figure is extracted, a circumscribed rectangle is set for the connected figure, and its position and size are calculated.

Next, it is determined whether or not the circumscribed rectangle is larger than a preset value.

Here, the value set in advance is a value corresponding to the size of one block on the drawing D. That is, the vertical size of one block is V, the horizontal size is H, and a rectangle of (1 + α) V in the vertical direction and (1 + β) H in the horizontal direction is set as a setting value. The values of α and β are arbitrary.

If the circumscribed rectangle is smaller than this set rectangle (vertical length of circumscribed rectangle ≦ (1 + α) V, horizontal length ≦ (1 + β)
H) performs a disconnection process of the connected figure in the circumscribed rectangle. Note that this cutout figure is regarded as a character or a symbol in one block.

When the circumscribed rectangle is larger than the set rectangle (the vertical length of the circumscribed rectangle> (1 + α) V or the horizontal length> (1 + β)
In H), coordinate conversion processing is performed using the translation amount, inclination, and scale change amount of the drawing separately detected as to which position on the drawing D each vertex of the circumscribed rectangle on the image memory 2 corresponds.

Subsequently, it is determined which block on the drawing D contains the position of each vertex subjected to coordinate conversion. As a result, a plurality of blocks on the drawing D that span the circumscribed rectangle are determined.

An inner ruled line for dividing the plurality of blocks from each other on the drawing D is obtained. The number of ruled lines is (number of multiple blocks-
1).

Corresponding to these inner ruled lines, a similar ruled line is written on the image memory 2 as a line segment having a pixel value “0”.

The inner ruled line corresponds to the ruled line for dividing the block on the drawing D except for the outline of the circumscribed rectangle on the image memory 2.

As described above, the connected graphic such as the repeated graphic and the contact character is divided into a plurality of blocks on the image memory 2, and the graphic written for each block can be separated.

As described above, the image memory 2 is raster-scanned to extract all the connected figures, and the separation processing is executed according to the size.

Now, the concept of actually performing drawing processing according to the above flowchart will be described with reference to FIGS. 3 (a) to (d) and FIGS. 4 (a) to (d).

FIG. 3 (a) shows that the letter “Y” on the drawing D
This is an example in which characters are repeated and a horizontal symbol "L" is repeatedly written except for both end blocks.

The image scanner 1 scans this drawing and stores binary image data in the image memory 2 as shown in FIG.

The control unit 3 performs raster scanning on the image memory 2 to detect a connected figure, and detects a horizontal line L. As shown in FIG. 3 (c), the control unit 3 obtains a circumscribed rectangle M1 of the horizontal line L, and obtains its position and size. Here, since one side of the circumscribed rectangle M1 is ▼> (1 + β) H, the following processing is performed.

Drawing D for each vertex Q1, Q2, Q3, Q4 of the circumscribed rectangle M1
, The vertices Q1 and Q2 are included in the block B1, and the vertices Q3 and Q4 are included in the block B3. It can be seen that the circumscribed rectangle M1 extends over the blocks B1, B2, and B3.

Next, on the drawing D, the inner ruled lines F1 (= ▲ ▼), F2 = (▲ ▼) for separating the blocks B1, B2, B3 from each other.
Ask for. In response to this, the pixel value "0" is stored in the image memory 2.
Draw line segments G1 and G2.

As a result, as shown in FIG.
The connected figure (horizontal line L) spanning 1, B2, B3 is line segment L1, L2, L3
Is separated for each block as in.

On the other hand, the characters "Y" at both ends are not separated into a plurality of blocks as one connected figure, and the block to which the character "Y" belongs is determined from the position of the center of gravity.

In this way, 5 characters are separated for each block,
Processing for each character can be performed.

FIG. 4 (a) shows four characters “Y” and “N” on drawing D.
Are written and touch each other (contact character C).

The image scanner 1 scans this drawing and stores binary image data in the image memory 2 as shown in FIG.

The control unit 3 raster scans the image memory 2, determines the four contact characters C as one connected figure, and obtains a circumscribed rectangle M2 as shown in FIG.

Here, regarding the sides of the circumscribed rectangle M1, ▲ ▼>
Since (1 + β) H or ▼ >> (1 + α) V, the following processing is performed.

Drawing D for each vertex Q5, Q6, Q7, Q8 of the circumscribed rectangle M2
When the corresponding coordinate position in is obtained, vertex Q5 is in block B
4, Q6 is found to be included in block B5, Q7 is included in block B6, Q8 is included in block B7, and circumscribed rectangle M2 is included in blocks B4, B5, B
You can see that it spans 6, B7.

Next, on the drawing D, the inner ruled lines F3 = (▲), F4 (= ▲) for dividing the blocks B4, B5, B6, B7 from each other.
▼), F5 (= ▲ ▼), F6 (= ▲
▼). Correspondingly, the line segments G3, G4, G5, G6 of the pixel value "0" are drawn on the image memory 2.

As a result, as shown in FIG.
4, the contact character C spanning B5, B6, and B7 is represented by line segments G3, G4, G5, and G6 for each block as characters C1 (Y), C2 (N), C3 (Y), and C4 (Y). Be separated.

As described above, a repeated figure, a contact character, and the like can be separated into each block.

<Effect of the Invention> The drawing reading processing method of the present invention extracts a connected graphic from the fixed format drawing information stored in the image memory, and only extracts the connected graphic if its circumscribed rectangle is larger than a predetermined value. By determining a plurality of blocks on the drawing over which the circumscribed rectangle straddles and drawing virtual rule lines on the image memory corresponding to the inner rule lines dividing the plurality of blocks, the corresponding connected figure is separated for each block. To get the effect.

Even if repeated graphic symbols and contact characters are separated, character symbols that slightly protrude from the block without touching the character symbol of the next block are not separated. Can be extracted as a symbol. Therefore, unnecessary recognition and erroneous recognition do not occur.

If there are no repetitive graphic symbols or contact characters, no separation is performed, and thus unnecessary processing steps are omitted.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an apparatus for realizing a drawing reading processing method of the present invention, FIG. 2 is a flowchart showing the drawing reading processing method of the present invention, and FIGS. FIGS. 4 (a) to 4 (d) are conceptual diagrams when the method of the present invention is applied to contact characters on the drawings, and FIG. 5 is a conceptual diagram when the method of the present invention is applied to graphic symbols. An example of a fixed format drawing targeted by the method,
FIG. 6 is a diagram for explaining a problem of the conventional drawing reading processing method. 1 ... Image scanner, 2 ... Image memory, 3 ...
Control unit, D ... fixed format drawing.

Claims (1)

(57) [Claims] An image scanner for scanning a fixed-format drawing in which characters and symbols are written in blocks divided by ruled lines, an image memory for storing obtained binary image data, and an overall control. A drawing reading processing method set in the control unit, wherein: (a) a procedure for raster-scanning the image memory to extract a connected figure; and (b) a circumscribed rectangle for the extracted connected figure. (C) determining the position and size of the circumscribed rectangle and comparing the size of the circumscribed rectangle with a preset value; A coordinate conversion procedure for converting coordinates into coordinate values on the drawing; and (d) determining which block in the drawing contains the obtained coordinate values to determine a plurality of blocks over which the circumscribed rectangle extends. (E) determining, on the drawing, an inner ruled line that divides the plurality of blocks determined in step (d) from each other, and a line having a pixel value “0” in the image memory corresponding to the inner ruled line; A drawing reading method, comprising: executing the steps of: (a) and (b) to separate the connected figure into blocks.