JPS62200472A - Line detector - Google Patents

Abstract

PURPOSE:To easily execute a detection of a line and an identification of a kind by dividing a stored image into a prescribed number of small areas, compressing them to one picture element, scanning it in the prescribed direction, changing in reverse a white picture element or a black picture element being below a prescribed length, respectively, and detecting a position of a linear shape from an area of a derived black picture element. CONSTITUTION:A compressed image in which a flat rectangle of (n) picture elements X(m) picture elements of an input image 9 which has been stored in an image storage means 1 is one picture element is generated by a compressing means 5 and stored. By a connected area detecting means 6, said image is scanned in the horizontal direction, a black picture element of a short part of the black picture element is changed to a white picture element, the white picture element of short length is changed to the black picture element and a compressed image 11 is obtained, and subsequently, an area to which the black picture element has been connected is detected. In a linear shape detecting means 7, a shape of the connected area is checked, a linear shape 12 is detected, and in a line kind discriminating means 8, a partial image on the input image 9 being in an area corresponding to the linear shape 12 is segmented and decided by deriving a photographic shadow 13 to an X axis and deriving a matching with information of a line which has been registered in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a line detection device that detects discontinuous lines such as broken lines and chain lines from images such as drawings and slips.

[Conventional technology]

FIG. 3 is a diagram showing the configuration of a conventional line detection device, which can be inferred from the broken line detection method found in, for example, the 1985 IEICE General National Conference, Ruled Line Recognition Software in rIWP, N11341.

In the figure, 1 is an image storage means for storing images of drawings, slips, etc., 2 is a broken line detection method for detecting broken line elements from the images stored in the image storage means 1, and 3 is based on the detected broken line elements. This is a continuity check means for checking the continuity of lines. FIG. 4 is a diagram for explaining the broken line detection method, and in the figure, 4 is a broken line element.

Next, the operation will be explained.

Out of the image containing the broken line stored in the image storage means 1, the component of a broken line or broken line is detected by the broken line front detection means 2 based on the shape thereof. The area before the broken line is classified into horizontal wavy line elements and vertical broken line elements (.

Next, the continuity check means focuses on two adjacent pieces of the four horizontal dashed lines, and checks the white ratio 1g/l a in the X direction based on the distance in the Y direction. It is determined whether the broken line is before the broken line within, and the broken line is sequentially grown.

[Problem that the invention seeks to solve]

Since the conventional line detection device was configured as described above,
It requires a lot of operations when joining the parts before the broken line, and
There were problems such as difficulty in distinguishing between the types of broken lines and chain lines.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a device that can easily detect broken lines and chain lines and also identify their types.

[Means for solving problems]

For this reason, the present invention includes a compression means 5 that divides a stored image into a predetermined number of small regions, compresses the divided small regions into one pixel, and scans the image compressed by the compression means 5 in a predetermined direction. a connected area detecting means 6 which changes white pixels or black pixels having a predetermined length or less into black pixels or white pixels, respectively, and calculates an area of connected black pixels; and a black pixel found by the connected area detecting means 6. linear shape detection means 7 for detecting the position of a straight line shape from the area of the compressed image, and line type discrimination means 8 for determining the type of line based on the shape on the area of the image corresponding to the area on the compressed image. It is characterized by the fact that it is equipped with

[Effect]

The compression means 5 according to the present invention divides the image stored in the image storage means 1 into a predetermined number of small areas, compresses the divided small areas into one pixel, and stores the compressed image. The connected area detecting means 6 scans the image compressed by the compressing means 5 in a predetermined direction, changes white pixels of a predetermined number or less between black pixels to black pixels, and finds an area of black pixels to be connected.

The linear shape detection means 7 detects the position of the linear shape from the black pixel area determined by the connected region detection means.

Further, the line type determining means 8 determines the type of line based on the shape on the area of the image corresponding to the area on the compressed image.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment, and the same reference numerals as in FIG. 3 indicate the same or corresponding parts, and the explanation thereof will be omitted.

In the figure, 5 is a compression means for creating and storing a compressed image of the image by making one pixel a small area of n pixels x m pixels of the image stored in the image storage means 1, and 6 is a compressed image. is scanned in the horizontal direction, and if there is a black pixel part shorter than a predetermined length, that black pixel is changed to a white pixel, and the white pixel whose length is shorter than the predetermined length is changed to a black pixel. 7 is a linear shape detecting means for detecting a linear shape among the connected regions detected by the connected region detecting means 6;
By cutting out a partial image corresponding to the connected area of the linear shape from the above image, mapping it to the X axis, and matching that information with the information registered in advance according to the type of each line. , is a line type discrimination means for discriminating the line type.

2a) to (C1) are diagrams showing the output of each processing unit of the above configuration, in which 9 is the input image, 10 is a dashed line, and 11 is the output after processing by the connected area detection means 6. This is a compressed image, and 12 is a linear shape, and 13 is an X-axis projection created by the line type discrimination means 8.

Next, the operation will be explained. A flat rectangle of n pixels x m pixels of the input image 9 stored in the image storage means 1 is
A compressed image made up of pixels is created by the compression means 5 and stored.

The connected area detection means 6 scans the compressed image in the horizontal direction and changes the black pixels in the short part of the black pixels to white pixels,
A compressed image 11 is obtained by changing short white pixels to black pixels and leaving only the long black pixel portions. Next, a region where black pixels are connected is detected.

Next, the linear shape detection means 7 examines the shape of the connected region and detects the linear shape 12.

Next, the line type determining means 8 cuts out a partial image on the input image 9 in a region corresponding to the linear shape 12 and obtains a projection 13 onto the X axis. Next, the information on the length of consecutive 1's of projection 13 (A, -j2f) and the length of O (g+ to g6), and the length of the line element 2 constituting the pre-registered line type. By determining the match with the interval information, it is determined which type of pre-registered line the detected line is.

Note that although only horizontal lines have been described above, the same effect can be obtained for vertical lines as well.

Further, the method used by the linear shape detection means is not limited to this, and any other method can be used as long as a broken line or a chain line can be detected as a single straight line, and the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As explained above, the present invention includes a compression means for dividing a stored image into a predetermined number of small regions and compressing the divided small regions into one pixel, and an image compressed by this compression means in a predetermined direction. a connected area detecting means for scanning a white pixel or a black pixel having a predetermined length or less and converting it into a black pixel or a white pixel, respectively, to find an area of connected black pixels; and a black pixel found by the connected area detecting means. linear shape detection means for detecting the position of the straight line shape from the region of the compressed image, and line type discrimination means for determining the type of the line based on the shape on the region of the image corresponding to the region on the compressed image. Therefore, it is possible to easily detect the line and also to identify the type of the line.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a line detection device according to an embodiment of the present invention, FIG. 2 is a diagram showing the output of each processing section of the embodiment, and FIG. 3 is a diagram showing the configuration of a conventional line detection device of this type. Diagram showing the configuration, No. 4
The figure is a diagram for explaining a method of detecting broken lines. In the figure, 1 is an image storage means, 2 is a broken line element detection means, 3 is a continuity check means, 5 is a compression means, 6 is a connected area detection means, 7 is a linear shape detection means, 8 is a line type discrimination means, 9 10 is an input image, 10 is a dashed line, 11 is a compressed image, and 12 is a linear shape 13 is a projection onto the X axis. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] Line detection that stores an image of a document, drawing, etc. in an image storage means, detects a line from the stored image, and determines the position of the line and its type, such as a broken line or a chain line. The apparatus includes a compression means for dividing the stored image into a predetermined number of small regions and compressing the divided small regions into one pixel; a connected area detecting means for determining a connected black pixel area by changing white pixels or black pixels having a length less than or equal to a black pixel or white pixel, respectively; and a line type determining means that determines the type of line based on the shape on the area of the image corresponding to the area on the compressed image. Line detection device.