JPH0488580A - Line segment integrating system - Google Patents

Abstract

PURPOSE:To obtain the line segment integration system, which can exactly integrate line segments at the place of wide or narrow line width and improve the compressibility of information as well, by integrating line segments by using line width information. CONSTITUTION:In order to integrate core information, a picture information processor 1 moves a program stored in an integrating method program area 142 through an external storage device control part to a main storage circuit 12 and according to the program on the main storage circuit 12, a central processing unit 11 is operated to integrate cores. By integrating information stored in a core information area 143 by using line width information, information having the small number of constitutive line segments and the compressed amount of data is stored in an integrated core area 144. Thus, the line segments can be exactly integrated by extracting a vector picture exactly expressing a raster picture even in the place of wide or narrow line width.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a line segment integration system used for compressing image data.

2. Description of the Related Art Conventionally, image raster-vector conversion of data has been performed, which involves inputting a raster image, such as a map, and compressing the data by expressing the raster image with line segments.

In this image raster-vector conversion, a method has been used in which a raster image is thinned, and then continuous line segments extracted by thinning are integrated using a certain threshold.

Problems to be Solved by the Invention However, in this conventional method, line segments are integrated using the same threshold regardless of whether the line width is large or small. There was a problem that I couldn't express it accurately.

An object of the present invention is to integrate line segments using line width information, so that line segments can be integrated accurately even in areas where the line width is large or small, and the information compression rate can be improved. The purpose of this invention is to provide a line segment integration system.

Means for Solving the Problems In order to achieve the above object, the line segment integration method of the present invention includes an image input device that inputs a raster image, and compresses data by expressing the raster image as line segments. The image information processing device has an image information processing device, and the image information processing device performs processing when line segments having line width information extracted from a raster image are continuous.
It is configured to integrate line segments using line width information.

Effects According to the present invention, with the above configuration, a vector image that accurately represents a raster image can be extracted by integrating line segments using line width information.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a line segment integration system according to an embodiment of the present invention.

Moreover, FIG. 2 is a front view showing the external appearance of the line segment integration system.

In FIG. 1, reference numeral 1 denotes an image information processing device, which is composed of a workstation. 2 is an image input device;
Consists of a scanner.

The image information processing device 1 has a keyboard 16 and 0RT1.
It is constructed by adding 7. Inside the image information processing device 1, there are a central processing unit 11, a main memory circuit 12, an external storage device control section 13, an external storage device 14, and an interface section 15.
is provided. The central processing unit 11 is a CPU.

The interface section 16 is a section that receives commands from the central processing unit 11 and sends and receives data and commands to and from the image input device 2 . Interface part 1
5 also transmits and receives data to and from the keyboard 16 and CRT 17 based on instructions from the central processing unit 11. The external storage device control unit 13 is a part that transmits and receives data to and from the external storage device 14 according to instructions from the central processing unit 11.

The external storage device 14 is a hard disk. The external storage device 14 is provided with an image data area 141, an integration method program area 142, a skeleton information area 143, and an integrated skeleton area 144. The main memory circuit 12 is a main memory circuit in the image information processing device 1.

Next, the operation will be explained.

FIG. 3 is an overall flowchart of this embodiment. FIG. 4 is an example of a line segment to be integrated.

The line segment shown in Fig. 4 is composed of 0 line segments connecting the points Px (x=o...n), and the line width of the line segment connecting the points Px and Px+1 is expressed as Wx. .

FIG. 6 shows a flowchart for performing line segment integration on line segments having line width information.

First, the entire processing procedure in this embodiment will be explained with reference to FIG.

In order to import image data into the image information processing device 1, the image information processing device 1 sends a command to the image input device 2, starts the image input device 2, and transfers the data to the image information processing device 1.
(Step 8301)
). Next, the image captured in the image data area 141 is converted into skeleton lines, and line segments having line width information are extracted. The core line processing is described in "Drawing processing using multidimensional data structure" (Transactions of the Institute of Electronics, Information and Communication Engineers (D) 1.tea-D No. 4
It is performed using the method described in Osawa and Sakauchi (1985) (
Step 8302).

The data resulting from performing this skeletonization process on the data in the image data area 141 is stored in the skeleton information area 143. Although the skeleton information area 143 stores data on many line segments, the following explanation will focus on one continuous line segment as shown in FIG. 4. Since it is sufficient to perform the following processing on all line segments extracted by core line processing, generality is not lost even if the single continuous line segment shown in Fig. 4 is used as an example.・.

In order to integrate core line information, the image information processing device 1 moves the program stored in the integration method program area 142 to the main memory circuit 12 through the external storage device control unit 13, and transfers the program stored in the integration method program area 142 to the main memory circuit 12. The central processing unit 11 operates according to a program in the program and integrates the core wires.

By integrating the information stored in the skeleton information area 143 using the line width information, information with a reduced number of constituent line segments and a compressed amount of data is stored in the integrated skeleton area 144 (step 5303 ).

Next, a line segment integration method using line width information will be explained with reference to FIGS. 4 and 6.

It is assumed that line segments consisting of points Px (x=o...n) shown in FIG. 4 are integrated. First, in Fig. 6 (step 56
01), initialize i = O, j = 1. I represents the starting point of the line segment to be integrated, and J represents the end point of the line segment integration.

Next, it is checked whether Pj is the end point of a continuous line segment (step 8502). P'' is the end point of the continuous line segment, then from Pi to P as shown in step 5610.
'' is represented by a line segment PiPj and the process is completed. Currently i =
Since O,j = 1, the process advances to step S503. In step S603, Px(x=i...
'') to calculate the least squares straight line equation E. A least squares straight line is a straight line that minimizes the sum of distances from each given point, and in this case, Px (x-1...j)
A straight line that minimizes the sum of the distances between As a method for calculating this least squares straight line, for example, the method described in "Fundamentals of Character/Graphic Recognition Technology" (Shunji Mori, Ohmsha, 1984) may be used.

Next, calculate the distance Dx between each point Px (x=i...J) and the least squares straight line (step S504). At all points Px (x=i..."), Dx< Wx
If /T (condition α) is satisfied, the process proceeds to step 5609; if not, the process proceeds to step S506 (step 8505). At this time, Wx is the line width at point Px, and T represents a certain constant.

Currently, i=o and j=1, so the least squares straight line between the points P1 and P'' is the same as the line segment PiPj. Therefore, since the distance Dx at each point Px (x-0, 1) is 0, each point Px (x=0, 1) all satisfies the condition α. Therefore, the process advances to step 5609. Step S
In step 509, j=2, and then in the same manner, step S
Proceed to 604, point Px (x=:O...2) and minimum 2
It is checked whether the distance between the vehicle and the vehicle line satisfies the condition indicated by the condition α.

Assume that the processing has progressed to 1-0, J=3. At this time, it is assumed that the condition α shown in step 5506 is not satisfied. At this time, the process advances to step 5506, where H=2.

In step 5607, the line segment between point PO and point P2 is approximated by line segment POP2.

Next, the process is set as 1-j-2 (step 8508) and the process proceeds to step 5502.

This is repeated until j = n, and if j = = n is satisfied in step 5502, step 8510
Then, approximation is performed using a line segment P1Pn between point P1 and point Pn, and the process ends.

Although the explanation was given using the example of continuous line segments shown in Fig. 4,
It is clear that the present invention is equally applicable to any continuous line segment having line width information.

Effects of the Invention As described above, according to the present invention, by integrating line segments using line width information, a vector image that accurately represents a raster image can be extracted regardless of whether the line width is large or small. Accurate line segment integration can be performed. Furthermore, it is possible to further compress data obtained by vectorizing image data using skeletonization. Therefore, it is possible not only to improve the information compression rate and express image information with a smaller capacity, and to reduce the information storage area, but also to increase the data display speed.

[Brief explanation of the drawing]

Fig. 1 is a block wiring diagram of a line segment integration system according to an embodiment of the present invention, Fig. 2 is a front view showing the appearance of the embodiment, and Fig. 3 is an operation of the line segment integration system according to the embodiment. FIG. 4 is a conceptual diagram of continuous line segments to explain the operation of the line segment integration system in the same embodiment, and FIG. 6 is a flow chart to explain the operation of the line segment integration system in the same embodiment. It is. 1... Image information processing device, 2... Image input device, 1
1... Central processing unit, 12... Main memory circuit, 13.
...External storage device control unit, 14...External storage device, 1
6...Interface part, 16...Keyboard,
17...RT0 Name of agent Patent attorney Shigetaka Awano and 1 other person 2nd
Figure 1゜Figure 6

Claims (1)

[Claims] The image information processing device includes an image input device that inputs a raster image, and an image information processing device that compresses data by expressing the raster image with line segments, and the image information processing device includes line width information extracted from the raster image. 1. A line segment integration system characterized in that when line segments having a continuous line width are continuous, the line segments are integrated using the line width information.