JPH0475537B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field of the Invention> The present invention relates to a line figure coordinate reading device for inputting numerical values of line figures for computer processing. <Conventional technology> In recent years, the development of technologies such as CAD/CAM has been remarkable.
These techniques are a method of recording conventional design data in a computer's memory in order to improve design efficiency, and when creating a new design, the database is utilized. As is well known, computers store data as numerical data, and cannot store drawings in their original form. Therefore, it is necessary to read the coordinates of line figures drawn on the drawing. As a device for that purpose,
Conventionally, digitizers and the like have been widely used as devices of this type, and these devices consist of a flat substrate on which a drawing or the like is placed, and a reading section that specifies coordinate points and reads the coordinates. A stylus and a cassole are provided as the reading section. There are also mechanical and electromagnetic methods, but since these are known methods, their details will be omitted. <Problems with conventional technology> However, these drawbacks are that each coordinate point is a point,
It is necessary to specify and read the points. For example, when inputting a line segment with many bend points or curved parts of a hand-drawn figure, it is necessary to input each bend point, and for curved parts, it is necessary to input each line segment that can be regarded as a straight line. There is,
This requires a great deal of effort. <Objective and Structure of the Invention> In view of the above-mentioned drawbacks, the present invention aims to provide a coordinate reading device that can more easily digitize and read handwritten figures, etc. In other words, the device that the present invention aims to provide is:
Line figures are photoelectrically converted using a camera head made up of a CCD (charge-coupled device), the figure within the camera field of view is digitized using image processing technology, and the data created for each camera field of view is synthesized. This completes the graphic data. Furthermore, when quantifying figures within the camera's field of view, conventionally the camera's field of view was always only moved parallel to the XY axis directions, but in the present invention, it is configured so that it can be rotated, and at least The reading section is equipped with a device capable of detecting coordinate positions on the flat substrate at two or more locations.
Hereinafter, the coordinate reading device of the present invention will be explained based on the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention. That is, in the coordinate reading device shown in FIG. 1, a drawing 2 is placed on a flat substrate 1, and a reading section 3 is provided on a line figure 2a drawn in drawing 2. The planar substrate 1 is covered with a grid pattern.
It is equipped with wires that can be energized in the XY axis directions. Since this device has the same configuration as generally well-known digitizers and tablets, its explanation will be omitted here. The reading unit 3 is provided with a substantially square transparent window 3a in the center thereof as a camera field of view. Coils 4 and 5 are embedded on both sides of the transparent window 3a to detect the amount of translation and rotation angle of the current position of the reading section 3 with respect to the coordinate system on the flat substrate 1.
The center positions of the coils 4 and 5 have a known geometric distance from the center position of the transparent window 3a, that is, the cursor portion. The coils 4 and 5 correspond to a cursor section when configuring a conventional digitizer, tablet, etc. Furthermore, a camera 6 is provided above the transparent window 3a of the reading section 3 , and this camera 6
A photoelectric conversion element 8 provided in the photoelectric conversion element 8 photoelectrically converts the line figure 2a drawn in FIG. 2 through the lens 7. Furthermore, the reading section 3 is provided with a support rod 9 for raising and lowering the camera 6 in order to focus the line figure 2a. In addition, 10 is an arm supporting the lamp 11 that illuminates the transparent window 3a portion, 12 is a group of operation switches, and 13
is an electric wire for transmitting signals to an arithmetic circuit and an image processing section, which will be explained later in FIG. 2. Next, the operation of the reading coordinate system having these configurations will be explained with reference to FIGS. 2 to 4. FIG. 2 is a block diagram, FIG. 3 shows the position of a cursor moving along a line figure, and FIG. 4 is a processing flowchart. 1 to 4, first, the reading section 3 is manually set at the starting point of the line figure 2a drawn on FIG. 2. As shown in FIGS. Next, input with CCD camera 6, for example 256×
Camera field data A having a 256-bit pixel configuration is provided to the image processing section 20. This image processing unit 20 performs known numerical conversion such as thinning of raster data, connection after thinning, etc. of binary data of 0 and 1 for discrimination between white and black in the coordinate system of the camera field of view. . Here, the advantages of converting raster information into numerical values include the following. (1) For example, by setting the center of the camera field of view as the origin, each bit of the photoelectric conversion element 8 can be easily arranged in geometric correspondence. (2) When performing affin transformation of information within the camera's field of view to coordinates on a flat board 1 system, digitized data, that is, vector data, is more compressed than raster information, and the conversion time is reduced accordingly, so it is easier to read. Processing speed can be increased. Further, position information E indicating the position of the camera 6 with respect to the flat substrate 1 is provided to the arithmetic circuit 21 . This position information E indicates the amount of parallel movement and rotation angle of the camera 6 obtained by the coils at least two or more locations according to the present invention, coils 4 and 5 in the figure. In the arithmetic circuit 21, affine transformation coefficients are calculated from the coordinate information of the two locations of the coils 4 and 5. This makes it possible to detect the rotation angle of the camera field of view, which was previously impossible. That is,
Let the two points of the camera 6 position in the coordinate system on the planar substrate 1 be coordinates (x _a , y _a ) and (x _b , y _b ). This detection is performed at symmetrical positions with respect to the center of the camera's field of view, and the distance L between them is constant. Also, if the coordinates (c _x , C _y ) in the camera seat are the coordinates (T x , C _y ) in the plane substrate 1,
T _y ) is expressed as follows. That is, T _x T _y = P ₁₁ P ₁₂ P ₂₁ P ₂₂ C _x C _y + P ₁₃ P ₂₃ Here, P ₁₁ to _{P 13} and P ₂₁ to _{P 23} represent arbitrary affine constants, and P ₁₁ = P ₂₃ = (x _b −x _a )/L, −P ₁₂ =
P ₂₁ = (y _b − y _a )/L, P ₁₃ = (x _a + x _b )/2, P ₂₃
It is expressed as = (y _a +y _b )/2. Here, six values are obtained for the affine transformation coefficient, and it can be easily calculated by selecting L as a constant that is easy to calculate. Next, the output signal F corresponding to the affine transform coefficient calculated by the arithmetic circuit 21 is given to the arithmetic circuit 22. In the arithmetic circuit 22, the output signal B of the coordinate system of the numerical ratio data in the camera field of view given from the image processing unit 20 and the above-mentioned output signal F are operated, and the line figure 2a in the camera field of view is Visual field data value conversion is performed to determine which coordinate position is represented in the above coordinate system. Then, the output signal C of the converted visual field data value is given to the arithmetic circuit 23. Here, as shown in Figure 3, it is determined whether the outermost frame within the camera field of view, that is, the field of view boundary data, is part of the data within the field of view that has already been obtained, and these lines are drawn. . This situation can be seen in the third
This will be explained in detail based on FIGS. In Figures 3 and 4, 3 _a-1 , 3 _a-2 , 3 _a-3
indicates the camera field of view (hereinafter simply referred to as field of view), and P ₁ to P ₁₁ indicate points at both ends of the line segment obtained with respect to the camera position. Here, when reading the line figure 2a as shown in Figure 1, the boundary data _P2 is first registered for the point _P1 in the field of view 3a _-1 , and _{the line segment l1 of 12 is obtained} . It will be done. Next, the camera field of view is sequentially translated and rotated to sequentially move to fields of view 3 _a-2 and 3 _a-3 . At this time, in the field of view 3 _a-2 , the boundary data points P ₃ and P ₅ are registered with respect to the point P ₄ in the field of view, and the line segment l ₂ of _{3 4} and the line segment l ₃ of _{4 5} are obtained. , point P ₇ of boundary data is registered with respect to point P ₆ in the field of view, and line segment l ₄ of _{4 6} and line segment l ₅ of _{6 7} are obtained. Furthermore, in field of view 3 _a-3 , point P ₁₀ in the coordinates for point P ₉ in the field of view
and boundary data points P ₈ and P ₁₁ are registered,
Line segment l ₆ of P ₈ P ₉ , line segment l ₇ of _{9 10} , and line segment l ₈ of _{9 11} are obtained. Next, these line segments _l1 to _l8 will be explained with reference to FIG. When moving the camera head from field of view 3 _a-1 to field of view 3 _a-2 , in step 3, field of view 3 _{a-1
The area} of _the triangle with respect to _{the point P 2 of} the boundary data in
Generate P ₄ P ₆ , △P ₂・P ₆ P ₇ . In step, it is determined whether the area is zero or not. If it is zero in the step, it is considered that the lines overlap, so two straight lines are generated for the field of view 3a _-2 . That is, if the area of the triangle generated by point P ₂ and line segment l ₂ is zero, point P ₂ is on line segment l ₂ . Therefore, two line segments _{1 3} and P ₁ P ₄ are generated. In the step, the longest straight line P _{1 P 4 among the straight lines P 1} P ₂ , P ₁ P ₃ , _and P ₁ P ₄ becomes _a new line segment. In addition,
The boundary data of visual field 3 _a-1 is within visual field 3 _a-2 and does not overlap with the boundary data of visual field 3 _a-2 .
If they overlap, move the camera and view 3 _a-
Set the boundary data of ₁ within field of view 3 _a-2 . Next, in the step, if the area is not zero, the line segments l ₃ and l ₅ are in the field of view 3 _a in the step.
It is determined whether or not the boundary data is within _-2 , and a new line segment is obtained in step. In other words, the point
Since the areas of the triangles between P ₂ and line segment l ₃ , point P ₂ and line segment l ₄ , and point P ₂ and line segment l ₅ are not zero, the lines l ₃ to l ₅ described above as new line segments are It will remain as it is. Further, in a step for reading data within the visual field 3 _a-3 , a point P ₇ of boundary data of the visual field 3 _a-2 is registered. Next, move the camera head from field of view 3 _a-2 to field of view 3 _a-3.
When moved to , the calculation is performed sequentially from step to step as described above, and the calculation is performed in a straight line.
P ₆ P ₉ and line segments l ₇ and l ₈ are obtained, and point P ₁₁ is registered. Note that this device can also be used to read conventional line figures. For example, if the arrangement is such that the coordinates of the midpoint of the two coils 4 and 5 indicate the center position of the cursor section, it is possible to read the points of the line figure without using the camera 6. Further, although the reading section 3 is provided with coils 4 and 5 as means for detecting the current position of the reading section 3 , any means may be used as long as the current position of the reading section 3 is known. Further, the relationship between the dimensions of the line figure 2a and one dot of the photoelectric conversion element 8 is determined by changing the magnification of the lens 7 or the like. Further, even if a microprocessor or the like is used in the arithmetic circuit described in FIG. 2, the above-mentioned functions can be fulfilled. In this way, a signal D is outputted from the arithmetic circuit 23, which converts data such as a straight line into data based on the coordinate system on the flat substrate 1 each time the reading section 3 moves.
For example, it is stored in an electronic computer. <Effects of the Invention> As explained above, according to the present invention, a camera head made up of a CCD is incorporated into a coordinate reading device, and means for detecting the coordinates of the current position at at least two locations are provided to detect the parallelism of the cursor portion. By calculating the movement and rotation angles and converting them into numerical values, it has been possible to reduce the amount of labor required to read curved sections in the past. Also, the cursor area
By making it possible to rotate instead of just moving in parallel to the The line figure reading time has been shortened. Therefore, since the coordinate reading device according to the present invention is easy to operate, it is highly useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the coordinate reading device according to the present invention, FIG. 2 is a block diagram, FIG. 3 is a diagram showing the position of a cursor section moving along a line figure, and FIG. 4 is a processing diagram. Showing a flowchart. DESCRIPTION OF SYMBOLS 1...Flat substrate, 2a...Line figure, 3 ...Reading part, 3a...Transparent window, 6...Camera, 8...Photoelectric conversion element.

Claims (1)

[Claims] 1. Equipped with a planar substrate for reading coordinates, a reading unit movable on the planar substrate, the reading unit includes a camera provided above a transparent window for reading line figures, and a photoelectric conversion device provided in the camera. The coordinates of the current position of the element and the reading section on the planar substrate are at least 2
The device is equipped with a means for detecting a point or more in the reading section, and digitizes the figure within the field of view of the transparent window of the reading section in the field of view coordinate system to obtain a straight line etc. at each movement of the reading section. Calculate the amount of translation and rotation angle of the position with respect to the coordinate system on the flat substrate for each movement, convert data such as the straight line into data according to the coordinate system on the flat substrate for each movement of the reading unit, and A coordinate reading device characterized by composing figures within a field of view of a transparent window.