JPH02176973A - Drawing read processing method - Google Patents

Abstract

PURPOSE:To improve the disconnection processing of graphic symbols and contact characters by dividing a connection figure into plural blocks according to the size of its circumscribed rectangle, drawing inside ruled lines sectioning the blocks, and extracting characters and symbols included in the connection figure. CONSTITUTION:A fixed format drawing D is scanned by an image scanner 1 and the read drawing information is stored in an image memory 2 as a binary- coded image signal. A control part 3 checks the size of the circumscribed rectangle of the connection figure on an image memory, detects blocks wherein the vertexes are on the drawing when the size is larger then a prescribed value to detect the blocks that the circumscribed rectangle touches, and draws the inside ruled lines with the picture element value '0' so as to section the blocks, thereby performing the disconnection processing of the blocks of the connection figure. Consequently, the graphic symbols and contact characters drawn on the fixed format drawing where the ruled lines, etc., are printed in dropout color are disconnected efficiently by the blocks.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a drawing reading processing method set in a device that reads handwritten drawings and performs image processing and drawing recognition processing.
In particular, it improves the separation processing of graphic symbols and contact characters that span multiple blocks written on a fixed format drawing in which ruled lines are printed in dropout color and divided into blocks by the ruled lines.

<Prior Art> A drawing reading device that reads a standard format drawing in which ruled lines are printed in dropout color and characters and symbols are written in blocks separated by the ruled lines is used to read the read characters and symbols. It is necessary to determine which row and column of block corresponds to in the drawing.

An example of the standard format drawing to be read as described above is shown in FIG.

This standard format drawing has ruled lines F, printed characters "symbols" and "rules" printed in dropout colors (colors ignored by the image scanner in the drawing reading device), and is divided into blocks B by ruled lines 1fflF. has been done.

For example, assume that the characters 'YJ+rNJ are written by hand on such a drawing in the blocks of the rule fence.

In order to save the time and effort of filling in the drawings, when the letter "Y" continues for five characters horizontally, a horizontal line "" is used as a repetition symbol.
= (L) or the letters rpJJ are 4 vertically
When characters continue, use a vertical line ``1 (
) may be used. In addition, symbols on the top, bottom, left, and right may touch each other (contact character C).

In either case, these graphic symbols and contact characters C span multiple blocks in the upper, lower, left, and right directions, so in order to position the characters and symbols written within one block, these connected figures must be separated for each block. There must be.

The conventional method for separating connected figures is to input the relevant drawing as an image, store the binary image data in an image memory, and then set virtual ruled lines on the image memory with pixel values corresponding to the ruled lines on the drawing. 0'', the image memory is divided into blocks in a grid pattern, and connected figures are separated. Here, on the image memory, a pixel value of "1" indicates a graphic part, and a pixel value of "0" indicates a background part.

<Problems to be Solved by the Invention> However, the conventional separation method described above 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 is drawn. (or symbol)'
If you slightly overflow the block when writing "YJ, rN", the characters will be unnecessarily separated as two characters, causing unrecognizability or erroneous recognition during the recognition process.■ This process of drawing the virtual ruled line G is repeated. If there is no graphic symbol (such as L), it will be a wasteful processing step.

The present invention aims to solve the above two problems,
To provide a method for efficiently separating graphic symbols and contact characters written on a fixed format drawing in which ruled lines are printed in dropout color and divided into a plurality of blocks by the ruled lines into blocks.

Means for Solving the Problems> The present invention stops drawing virtual ruled lines over the entire image memory, extracts connected figures on the image memory,
Look at the size of the circumscribed rectangle and divide it into multiple blocks,
Characters and symbols included in the connected figures are extracted by drawing inner ruled lines that separate the plurality of blocks.The specific processing procedure is as follows.

The present invention consists of an image scanner that scans a fixed format drawing divided into blocks by ruled lines and characters and symbols written in each block, an image memory that stores the obtained 2r1 image data, and a control unit that controls the whole. The drawing reading processing method set in this control unit includes: (a) raster scanning the image memory to extract a connected figure; and (b) setting a circumscribing rectangle to the extracted connected figure. (c) find the position and size of the circumscribed rectangle, and compare the size of this circumscribed rectangle with a preset value; (d) a step of determining which block in the drawing the obtained coordinate value is included in and determining a plurality of blocks spanned by the circumscribed rectangle; E) A step of finding an inner ruled line that mutually divides the plurality of blocks determined in step (d) on the drawing, and drawing a line segment of the image chain "0" on the image memory corresponding to this inner ruled line. This drawing reading processing method is characterized in that the connected figures are separated into blocks by executing the following steps.

Function> The drawing reading processing method of the present invention checks the size of the circumscribed rectangle of connected figures on the image memory, and if it is larger than a predetermined value, detects the block containing the vertex on the drawing. A plurality of blocks spanned by this circumscribed rectangle are detected, and an inner ruled line is drawn with a pixel value of "0" so as to separate the plurality of blocks, thereby performing a process of separating blocks of connected figures.

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

A standard format drawing is scanned by an image scanner, and the read drawing information is stored in the image memory 2 as a 2m-converted image signal.In the image memory 2, the graphic part has pixel values corresponding to the drawing. This is a portion that temporarily stores binary image data in which the pixel value is “1” and the background portion is “0”.

The control unit 3 is composed of a microprocessor, etc., and performs overall control, and also performs raster scanning of the image memory 2, extracts connected figures, and coordinates points on the image memory 2 and coordinate points on the drawing. This is the part that executes the method of the present invention, such as coordinate transformation processing for one-to-one correspondence and line segment generation processing for the image memory 2.

Although such a configuration is similar to that of a conventional drawing reading device, the present invention is characterized by the processing operations set in the control section 3.

Further, the fixed format drawing to be read is a drawing in which repeated graphic symbols such as those shown in FIG. 5 are written by hand, and connected figures such as contact characters C can be seen in various places.

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

The principle of the drawing reading processing method of the present invention will be briefly explained according to this flowchart.

When the 11 section 3 is activated, the image scanner 1 reads a handwritten standard format drawing 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 connected figures such as characters, symbols, repeated graphic symbols (vertical lines, horizontal lines, etc.), touching characters, and the like.

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 this circumscribed rectangle is larger than a preset value.

The preset value here is a value corresponding to the size of one block on the drawing. That is, the vertical size of one block is V, the horizontal size is H, and the set value is (1).
+α)■, set a rectangle with the side (1+β)H,
The values of α and β are arbitrary.

If the circumscribed rectangle is smaller than this setting rectangle (vertical length of circumscribed rectangle ≦ (1 + α) V, horizontal length ≦ (1 + β) H
) performs a process of cutting out connected figures within this circumscribed rectangle, and this cut-out figure is regarded as a character or symbol within one block.

If the circumscribed rectangle is larger than the set rectangle (vertical length of circumscribed rectangle > (1 + α) ■ or horizontal length > (1 + β) H
) performs coordinate conversion processing to determine which position on the drawing the vertices of the circumscribed rectangle on the image memory 2 correspond to, using separately detected amounts of parallel movement, inclination, and scale change of the drawing.

Next, it is determined which block on the drawing contains the position of each vertex whose coordinates have been transformed. As a result, a plurality of blocks on the drawing that this circumscribed rectangle spans are determined.

Inner ruled lines that mutually separate these multiple blocks are determined on the drawing. Number of ruled lines multiplied by number of blocks - 1
).

Corresponding to these inner ruled lines, similar ruled lines are written on the image memory 2 as line segments with pixel values of "0".

Moreover, these inner ruled lines correspond to the ruled lines for dividing blocks on the drawing, excluding the outline of the circumscribed rectangle on the image memory 2.

As described above, the corresponding connected figures such as repeated figures and touching characters are divided into a plurality of blocks on the image memory 2, and the figures written in each block can be separated.

In this way, the image memory 2 is raster-scanned to extract all connected figures, and a separation process is executed depending on their size.

Now, the concept of actually reading and processing drawings according to the above flowchart is explained in Figures 3 (a) to (d) and 4.
This will be explained using Figures (A) to (D).

FIG. 3(a) is an example in which five letters "Y" continue horizontally on the drawing, and a repeat symbol horizontal line "L" is written except for the blocks at both ends.

The image scanner 1 scans this drawing and stores binary image data in the image memory 2 as shown in FIG. 3 (b).

The control unit 3 raster-scans the image memory 2 to detect connected figures and detect horizontal lines. As shown in FIG. 3(c), the control unit 3 determines a circumscribed rectangle M1 with horizontal lines, and determines its position and size. Here, since one side of the circumscribed rectangle M1 is 1 (10 β) H, the following processing is performed.

Each vertex Ql, Q2 of the circumscribed rectangle M1. Q3. Regarding Q4, when finding the corresponding coordinate position in the drawing, the vertex Ql
, Q2 is block Bl, vertex Q3°G4 is block B3
It turns out that the circumscribed rectangle M1 is included in the block B
l, B2. It can be seen that it spans B3.

Next, block Bl, B2 . Inner ruled lines Pi (=P3P4), F2 (=P5
P6) is found. Correspondingly, line segments Gl and G2 of pixel value "0" are drawn on the image memory 2.

As a result, as shown in FIG. 3(d), block Bl
, B2. The connected figure (horizontal line L) spanning B3 is line segment Ll
, L2. Each block is separated like L3.

On the other hand, the character "Y" at both ends is treated as one connected figure, and is not separated into multiple blocks, but the block to which it belongs is determined based on its center of gravity.

In this way, 5 characters are separated for each block, -
It becomes possible to process each character.

Figure 4 (a) shows four letters "Y" on the drawing.

This is a case where "N" is written and they touch each other (contacting letters C).

The image scanner 1 scans this drawing and stores binary image data in the image memory 2 as shown in FIG. 4(b).

The control unit 3 raster-scans the image memory 2, and
As shown in FIG. 3, the four touching characters C are determined to be one connected figure, and its circumscribed rectangle M2 is determined.

Here, each side of the circumscribed rectangle M2 is 8〉(1
+β)F5 or Q5Q6> (1+a)■, so the following process is performed.

Each vertex Q5 of the circumscribed rectangle M2. Q6. Q7. Regarding Q8, when finding the corresponding coordinate position in the drawing, the vertex Q5
is block B4. Q6 is block B5. G7 is block B6. It turns out that Q8 is included in block B7, and the circumscribed rectangle M2 is included in block B4. B5. It can be seen that it spans B6 and 87.

Next, block B4. B5. B6゜Inner ruled line F3 (=P11P12) F4 that separates B7 from each other
(=P10P12), F5 (=P12P16)
, F6 (=P12P14) is calculated. Correspondingly, a line segment G3. with a pixel value of "0" is displayed on the image memory 2. G4. G
5. Pull G6.

As a result, as shown in FIG. 4(d), block B4
．． B5. B6. The touching character C that spans B7 is the line segment G3.
G4. G5. Letters C1 (Y), C2 (N) by G6
, C3(Y), and C4(Y).

In the above manner, repeating figures, touching characters, etc. can be separated into blocks.

<Effects of the Invention> The drawing reading processing method of the present invention extracts connected figures from the fixed format drawing information stored in the image memory, and extracts connected figures from the fixed format drawing information stored in the image memory, and extracts the connected figures only when the size of the circumscribed rectangle is larger than a predetermined value. By determining multiple blocks on the drawing that the circumscribed rectangle spans, and drawing virtual ruled lines on the image memory corresponding to the inner ruled lines that divide the multiple blocks,
Since the corresponding connected figures are separated into blocks, the following effects are obtained.

■ Even if repeating graphic symbols and touching characters are separated, character symbols that do not touch the adjacent block's character symbol and extend a little beyond the block will not be separated, so this character symbol cannot be separated into one character symbol. Can be extracted as a character symbol.

Therefore, unrecognizability and erroneous recognition will not occur unnecessarily.

■ If there are no repeating graphic symbols or touching characters, no separation is performed, eliminating unnecessary processing steps.

[Brief explanation of the drawing]

Figure 1 is a block diagram of the configuration of a device that implements the drawing reading processing method of the present invention, Figure 2 is a flowchart showing the drawing reading processing method of the present invention, and Figures 3 (a) to (d) are repetitions on the drawing. A conceptual diagram when the method of the present invention is applied to graphic symbols, Figures 4 (a) to (d) are conceptual diagrams when the method of the present invention is applied to contact characters on drawings, and Figure 5 is a conceptual diagram of the method according to the present invention An example of a standard format drawing covered by the method,
FIG. 6 is a diagram for explaining the problems of the conventional drawing reading processing method. 1... Image scanner, 2... Image memory, 3
...Control unit, D...Standard format drawing. Diagram

Claims (1)

[Claims] (1) An image scanner that scans a standard format drawing divided into blocks by ruled lines and characters and symbols written in each block, an image memory that stores the obtained binary image data, and a control unit that controls the entire thing. The drawing reading processing method set in this control unit includes (a) a step of raster scanning the image memory to extract connected figures; and (b) setting a circumscribing rectangle to the extracted connected figures. (c) If the circumscribed rectangle is large in step (b), calculate the coordinates of each vertex of this circumscribed rectangle. (d) a step of determining which block in the drawing the obtained coordinate value is included in and determining a plurality of blocks spanned by the circumscribed rectangle; E) A step of determining an inner ruled line that mutually divides the plurality of blocks determined in step (d) on the drawing, and drawing a line segment with a pixel value of "0" on the image memory corresponding to this inner ruled line. A drawing reading processing method characterized in that the connected figures are separated into blocks by executing the drawing processing method.