JPS6170667A - Line image forming device - Google Patents

Abstract

PURPOSE:To speed up operation by providing the 1st frame memory where a line image is written and the 2nd frame memory where branch information on the number of branches at each point on said line image and their directions is written, and performing tracking operation with the 2nd frame memory. CONSTITUTION:An original image 1 is converted into a line and dot image by a line and dot image forming part 3 and it is stored in the 1st frame memory. The, a branch information conversion part 5' obtains information consisting of at least eight bits for every image, element as the branch information on the number of branches on each image element in said line and dot image and their directions and writes it in the 2nd frame memory. Then, a line tracking part 7' performs the tracking operation on the basis of the branch information to form a line image, data of the formed line image is returned to a control part 2'. Therefore, when a line is tracked in the 2nd frame memory, it is not necessary to recalculate which direction a branched line image point is in, so the line image is formed at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an apparatus for tracing lines on an image constituting a line figure and creating a line drawing in the field of image processing and graphic processing using visual information. It is.

Conventional configuration and its problems Generally, when performing image processing and graphic processing, frame and
In many cases, an image is formed on a memory and the information on the memory is processed by a computer. Furthermore, the technology of processing the image information on the frame memory to construct a line figure and create a line drawing is called image processing 1 figure processing. This is one of the most important.

Here, pixels representing a line figure on the frame memory are called line drawing points, and conventionally, the number of branches has been used to track these line drawing points. Conventional line tracing using this number of branches will be explained using FIGS. 1 to 6.

Reference numeral 1 denotes an original image, and in response to a command from the control unit 2, a line drawing point image creating unit 3 converts the original image 1 into a line drawing point image 4 indicating whether each pixel is a line drawing point or not. Further, in response to a command from the control section 2, the branch number generation section 5 converts the line drawing point image 4 into a branch number image 6 in which each pixel indicates the number of branches at that point. The number of branches is processed as follows.

FIG. 2 shows a pixel X focused on the line drawing point image 4 and eight adjacent pixels X around it. -x7. The number of branches in each pixel is 8 adjacent pixels X, as shown in the flowchart shown in FIG. - Count the number of line drawing points among x7. However, when counting, priority is given to the horizontal and vertical directions, and when there are line drawing points in the horizontal and vertical directions, pixels diagonally adjacent to the pixel of interest on both sides are not counted in the number of branches even if they are line drawing points. shall be.

When the branch number image 6 is obtained as described above, the control unit 2
issues a command to the line tracing unit 7, and the line tracing unit 7 outputs the branch number image 6.
Trace the line by accessing .

A means for tracing a line using this number of branches will be explained with reference to FIG. The Mononoke line drawing points are indicated by circles in the figure. The number shown inside the O mark is the number of branches. Fourth
Figure a shows an example of a pattern realized in a branch number image. When focusing on point A, since the number of branches at point A is 1, it can be seen that there is only one adjacent line drawing point. When searching for adjacent line drawing points in the surrounding 8 neighboring points, point B is found, so the point of interest is shifted to point B. At this point point A
By decreasing the number of branches of and point B by 1, point A
The adjacency relationship between and point B is eliminated (see Figure 4). Thereafter, the point of interest is moved to E using the same means to complete the line tracing (see C1d in FIG. 4).

Next, FIG. 5 shows an example of a frame memory representing a branch number image 6.

Assume that we are currently tracing a line and are focusing on pixel F. The number of branches of pixel F is 2, and the line tracing unit 7
The value 1 obtained by subtracting 1 from 2, which is the number of branches, must be written in pixel F, and the pixel of interest must be moved to pixel G or pixel H. However, in order to know that the pixels branching from pixel F are pixel G and pixel H, and not pixel work or pixel ■, it is necessary to investigate again using the same method as the flowchart shown in Figure 3. ineffective.

Purpose of the Invention The present invention eliminates the above-mentioned drawbacks of the conventional art, and by predetermining the direction of the connection relationship between adjacent line drawing points, there is no need to recalculate the direction of branching when tracing a line, and the method is simple. The purpose is to create line drawings.

Structure of the Invention The present invention provides means for writing a line figure on a first frame memory in which each pixel is composed of binary values, and a means for writing a line figure on a first frame memory in which each pixel has a binary value, and a means for writing a line figure on a first frame memory in which values of eight pixels adjacent to each point on the line figure of the first frame memory are written. Refer to the branch information indicating the number and direction of branches at each point on the line shape.
A line drawing creation device comprising means for writing into a second frame memory having at least 8 bits for each pixel, and means for creating a line drawing by tracing a line while referring to branch information in the second frame memory. Yes, you can easily create line drawings.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 6 to 13. Reference numeral 1 denotes an original image, and in response to a command from a control unit 2', a line drawing creation unit 3 converts the original image 1 into a line drawing point image 4 indicating whether each pixel is a line drawing point or not.

Further, in response to a command from the control section 2', the branch information conversion section 5' converts the line drawing point image 4 into a branch information image 6' in which each pixel indicates branch information and each pixel has 8 bits.

Next, the control section 2' issues a command to the line tracing section γ', and the tracing section 7
' creates a line drawing by tracing the line by accessing the branch information image 6', and returns data of the created line drawing to the control unit 2'. 10us-7rem・
It is a memory, and each pixel is composed of binary values indicating whether it is a line drawing point or not.If a point P1 is shown in the frame memory 0 with coordinate values X, YK, l: do.

The value of point P on the frame memory 10 moves to point B3, and after a certain time interval T has elapsed, the first scanning device 11 moves the point of interest from Pl to the adjacent point P2.

14 to 19 are delay circuits, and the points of interest are from Pl to P2.
When moving to point B3, the value of point B3 changes to point B2, and the value of point B2 changes to point B.
1, the value of point B4 moves to point B', the value of point B moves to point B0, the value of point B6 moves to point B6, and the value of point B6 moves to point B7. 12 is a line buffer, in which the delay circuit is arranged in horizontal pixel values, and the first point of interest is from Pl to -
When you finish scanning the row and move to P3, the value of B3 becomes B4.
, the value of B4 moves to B6, respectively.

The branch information conversion table 20 shown in FIG.
7 is input, and the value of the branch information represented by the 8-bit value is written to the point Q1 indicated by the coordinate values X and Y on the second frame memory 21.

A second scanning device 22 moves the point of interest in synchronization with the first scanning device 11. Here, branch information conversion table 2
The contents of 0 will be explained below. FIG. 9 illustrates the value of point B, Bo-B7 in FIG. 7 or FIG. 8, and the meaning of bo-b7.
The value corresponding to is b, which is the value of point B0. is frame/
memory.

Above, it is the value of the pixel on the right side of point B, and the value b6 of point B1 is the value of the pixel on the upper right side of point B on frame memory 0. The same holds true up to point B7. These values. -b7 are sequentially arranged on an 8-bit memory as shown in FIG. 10 and converted according to the flowchart shown in FIG. 11, which is represented as branch information.

Using this branch information, by referring to the value of each pixel, it is possible to immediately know in which direction adjacent line drawing points exist from that pixel.

FIG. 12 shows a pattern similar to that showing the number of branches in FIG. 6 using branch information. However, the branch information shown inside the circle is a hexadecimal value.

For example, F has a hexadecimal value of 45, but if you look at this in Figure 9, you will see bo, b2. It can be seen that b6 is set to 1. This shows that there are line drawing points in three directions: adjacent to the right, adjacent to the top, and adjacent to the bottom when viewed in FIG.

In this embodiment, conversion is performed using a branch information conversion table shown in a table calculated in advance according to the flowchart shown in FIG. The input to this table is the 8-bit value shown in FIG. 10, with the upper 4 bits and lower 4 bits each expressed in hexadecimal. The output value retrieved by the table is written at point Q1 in FIG.

Table 6 shows an example of a pattern realized based on the line tracing means based on FIG.
Since the value of the dot is 02 in hexadecimal, it can be seen that the adjacent pixels are in the upper right direction. Point M, which is moved one pixel to the upper right from the point, contains the value 2o indicating the opposite direction to the value 02 of the branch information of the point, so change 02 from the value at the point,
By subtracting 20 from the value of point M, the adjacency relationship between the point and point M can be eliminated. At this time, the point of interest is moved from L to M (see Figure 13). Thereafter, the point of interest is moved to O by the same means, and the tracing of the line is completed (see FIGS. 13c and d).

In addition, in the above embodiment, the branch information image 6' is composed of 8 bits, but even if a parity bit is added and the branch information image 6' is composed of 9 bits, it can be expanded such that the inversion of each bit is placed next to each other to create a 16-bit composition. Needless to say, the same effect can be obtained.

Effects of the Invention When using the video recording creating device of the present invention in a double manner, there is no need to recalculate in which direction branching line drawing points exist. Therefore, it has the effect that line drawings can be created more easily and faster than conventional methods.

[Brief explanation of drawings]

FIGS. 1 to 6 relate to conventional examples, and FIG. 1 is a block diagram of a line drawing creation device, and FIG. 2 is a pixel X focused on a line drawing point image and eight surrounding pixels x0 to I7. FIG. 3 is a flowchart showing the processing of branch information of the pixel of interest, FIG. 4 is an explanatory diagram of the tracking process of branch information after processing in FIG. 3, and FIG. 5 is a flow chart showing the processing of branch information of the pixel of interest The diagrams showing the later branching information, M6 to FIG. 13, are related to the embodiment of the present invention, and the IS diagram is a block diagram of the line drawing creation device according to the embodiment of the present invention, FIGS. 7 and 81.
The figure is a block diagram of the branch information conversion device in the same device, FIGS. 9 and 10 are explanatory diagrams of the meanings of the points in FIG. 7 or 8, and FIG. FIG. 12 is a diagram showing the branch information after processing in FIG. 10, and FIG. 13 is a process diagram of the line tracing method in an embodiment of the present invention. . 1...Original image, 2...Control unit, 3...
...Line drawing point image creation section, 4... Line drawing point image, 5... Branch number creation section, 6... Branch number image, 7...・Line tracing section, 2'...control section,
6'...branch information converter, 6'...branch information image, 7'...line tracing unit, 10...
. . . first frame memory, 11 . . . first scanning device, 12. 13 . . . line buffer, 14
~19... Delay circuit, 2Q... Branch information conversion table, 21... Second frame memory, 22S... First scanning device, A-1.・・・・・・
Points in the branch number image, B, B0 to B7... Points on the branch information conversion device, P,, P2. P3... Point on the first frame memory, Ql... Point on the second frame memory, b, b - b...
Values of point B, Bo-B7, K-P...points in the branch information image. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3171 Figure 5 Figure 4 Figure 6 Figure 71, Figure 8 Figure 2θ Figure 9 Figure 10 MSB LSβ Figure 11 Figure 12 Figure 13 (a)

Claims (1)

[Claims] means for writing a line figure on a first frame memory in which each pixel is composed of binary values; means for obtaining branch information indicating the number and direction of branches at each point in at least 8 bits for each pixel; means for writing the branch information into a second frame memory; A line drawing creation device comprising means for creating a line drawing by tracing a line while referring to branch information.