JP2797328B2 - Line shape judgment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for determining a line shape, and in particular, obtains coordinates of a target line in a three-dimensional space, and makes a quality judgment based on the three-dimensional shape. The present invention relates to an apparatus for determining a line shape.

[Conventional technology]

Conventional techniques include, for example, Guo, Yauchida, Tsuji, "A Method for Measuring Three-Dimensional Position of a Linear Object Using Shadow Information", IEICE Pattern Recognition and Learning Workshop PRL83-27 pp33-4
As shown in 0,1983, a method is proposed in which a linear object is illuminated with a point light source, the end point of the linear object and the position of the corresponding shadow are obtained, and three-dimensional coordinates for only the end point are obtained. Have been.

[Problems to be solved by the invention]

In the above-described conventional method, since the three-dimensional coordinates are obtained only for the end points, there is a disadvantage that the line shape cannot be obtained. Furthermore, when the positions of a plurality of shadows corresponding to the end point of the linear object are detected due to the influence of noise or the like, it has been impossible to obtain an accurate correspondence and three-dimensional coordinates.

[Means for solving the problem]

The apparatus for determining a linear shape according to the present invention includes a photoelectric conversion scanner for reading a linear object as an image signal, and two photoelectric conversion scanners arranged in a predetermined position symmetrical with respect to the photoelectric conversion scanner in an elongated line. A light source, a light source switching circuit for controlling whether one of the linear light sources is turned on, and an A / D converter for converting an image signal read by the photoelectric conversion scanner into a digital image. A circuit, and an image memory circuit for separately storing a digital image in a state where only one of the linear light sources is turned on and a digital image in a state where only the other is turned on,
A difference image calculation circuit for obtaining a difference image between the two stored images, an addition circuit for obtaining an addition image between the two stored images, and detecting a position of a shadow generated by each linear light source from the difference image Further, a labeling circuit for detecting the position of the target linear shape from the addition signal output from the addition circuit and performing separate label numbering on the detected shadow and the target position based on the connection relation, and a label numbering circuit. A corresponding point detection circuit that scans the label signal in the horizontal direction and obtains a corresponding point based on the corresponding positional relationship determined by the positions of the pre-arranged photoelectric conversion scanner and the linear light source of the shadow and the object, and the detected correspondence A three-dimensional shape calculation circuit for calculating a three-dimensional shape by calculating a three-dimensional coordinate position from a positional relationship, and a determination reference value set in advance from the calculated three-dimensional shape Configured to include a shape determination circuit for performing quality determination of the shape.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

An input image signal 5 read by scanning the photoelectric conversion scanner 1 is converted into a multilevel digital image 7 by an A / D conversion circuit 6.

Further, with respect to the photoelectric conversion scanner 1, two linear light sources 2 arranged in an elongated line at predetermined positions symmetrical with respect to the left and right are controlled by a light source switching power signal 4 output from a light source switching circuit 3. Only one of them is lit.

In the image memory circuit 9, the digital image 7 in a state where only one of the linear light sources 2 is turned on and the digital image in a state where only the other is turned on, based on a light source switching signal 8 output from the light source switching circuit 3. Image 7 is recorded separately.

Using an image memory signal 10 output from the image memory circuit 9, a difference image calculation circuit 11 calculates a difference between the two images and outputs a difference image 12, and an addition circuit 13 performs addition between the two images to perform addition. Outputs 14.

The labeling circuit 15 detects the position of the shadow generated by each linear light source from the difference image 12,
Thus, the label is detected at the position of the target line shape, and the detected shadow and the target position are assigned different label numbers based on the connection relationship, and the label image 16 is output.

The corresponding point detection circuit 17 scans in the water direction the label image 16 with the label number, and the corresponding positional relationship between the shadow and the target, which is determined by the positions of the photoelectric conversion scanner 1 and the linear light source 2 which are arranged in advance. And outputs a corresponding positional relation signal 18.

The three-dimensional shape calculation circuit 19 calculates a three-dimensional coordinate position of the target line shape from the corresponding positional relationship signal 18 and outputs a three-dimensional shape signal 20.

The shape determination circuit 21 determines the quality of the shape by performing a predetermined determination reference value from the three-dimensional shape signal 20 and outputs a determination signal 22.

 Next, details of each unit will be described.

FIG. 2 is an arrangement diagram of a photoelectric conversion scanner and a linear light source.

The world coordinate system 31 is set at a preset reference position, and the photoelectric conversion scanner 1 is arranged in the Z-axis direction of the world coordinate system. Further, the linear light source 2 is disposed at a position symmetrical with respect to the photoelectric conversion scanner 1 in the Y-axis direction.

FIG. 3 is an explanatory diagram of a method of calculating three-dimensional coordinates from the position of a shadow and an object.

Let the position M of the target line shape 30 in the world coordinate system be (a _x , a _y ,
a _z ), and the position on the camera imaging surface 41 is (I _m , J _m )
And The position of the shadow P generated by turning on the linear light source 2 (L _p ) on the camera imaging surface 41 is (I _p , J _m ), and the light source 2 (L _θ ) is turned on. If the position of the shadow θ on the camera imaging plane 41 is (I _q , J _m ), and Is geometrically determined from the arrangement of the photoelectric conversion scanner and the linear light source described above.

Here, L: distance between camera focal point and point 0 f: distance between camera focal point and camera imaging plane L ₁ ... distance between point 0 and point L _p β: angle L between X axis and straight line 0L _{p 2,} the angle of the distance gamma ...... X axis and the straight line 0L _theta between ...... point 0 and point L _theta.

Therefore, the corresponding position between the object and the shadow, that is,
If (I _m , J _m ), (I _p , J _m ) and (I _q , J _m ) are obtained, the position M (ax _x ) of the target line shape 30 in the world coordinate system can be obtained by the equations (1) to (5). , a _y , a _z ) are obtained.

Further, by comparing the calculation results of the expressions (1) and (4), the expressions (3) and (5), it is possible to determine whether the corresponding positional relationship is correct.

4 (a) to 4 (c) are explanatory diagrams of a method of obtaining a difference image and an addition image from the images stored in the image memory and performing label numbering.

FIGS. 4 (a) and 4 (b) show image signals 53 when only one of the above-mentioned linear light sources is turned on. Find the difference image between the two images, and the value is “negative”
Alternatively, it is possible to determine which of the linear light sources is the shadow by determining whether it is “positive” and exceeds a preset slice level.
Based on the connection relationship, separate label numbers p and q are assigned as shadow label numbers 56 as shown in FIG. 4 (c). On the other hand, an added image between the two images is obtained, and a position whose value exceeds a preset slice level is set as the target line shape, and the label number m shown in FIG. Attach as

FIG. 5 is an explanatory diagram of a method for obtaining a positional relationship between a shadow and an object.

By arranging the photoelectric conversion scanner and the linear light source as described above, the correspondence is horizontal scan lines.
You only need to look at 56. Further, the positions (I _m , J _m ), (I _p , J _m ) where the label number 55 of the target line shape and the label number 56 of the shadow are provided for each horizontal scan line 56.
And (I _q , J _m ) are obtained, and using equations (1) to (5),
It is possible to calculate the three-dimensional coordinates and determine whether the corresponding positional relationship is correct.

〔The invention's effect〕

According to the linear shape determination device of the present invention, two-dimensional light sources are alternately switched to obtain a correspondence between an object and a shadow based on an input image signal to calculate three-dimensional coordinates. It is possible to calculate the three-dimensional shape for all points of the object, and it is possible to judge whether the correspondence is correct, so that high-precision shape judgment can be made, and two linear light sources are alternately switched. Since the object and the shadow are detected by the difference image and the added image between the images, there is an effect that the image is not affected by noise or the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a layout diagram of a photoelectric conversion scanner and a linear light source shown in FIG. 1, and FIG. 3 calculates three-dimensional coordinates from the position of a shadow and an object. FIGS. 4 (a) to 4 (c) are explanatory diagrams of a method of obtaining a difference image and an addition image from images stored in an image memory and labeling the images, and FIG. It is explanatory drawing of the method of calculating | requiring the corresponding positional relationship of a shadow and an object. DESCRIPTION OF SYMBOLS 1 ... Photoelectric conversion scanner, 2 ... Linear light source, 3 ... Light source switching circuit, 4 ... Light source switching power supply signal, 5 ... Input image signal, 6 ... A / D conversion circuit, 7 ... Digital image , 8 ... light source switching signal, 9 ... image memory circuit,
10 ... Image memory signal, 11 ... Difference image calculation circuit, 12 ...
Difference image, 13 Addition circuit, 14 Addition image, 15 Labeling circuit, 16 Label image, 17 Corresponding point detection circuit, 18 Corresponding positional relationship signal, 19 Three-dimensional shape calculation Circuit, 20 three-dimensional shape signal, 21 shape determining circuit, 22
… Judgment signal, 30… Object line shape, 31… World coordinate system, 40… Camera focus, 41… Camera imaging plane, 42…
Shadow, 51 …… Target line shape data, 52 …… Shadow data, 53 ……
Image signal, 54: Label image, 55: Label number of target line shape, 56: Label number of shadow.

Claims (1)

(57) [Claims] 1. A photoelectric conversion scanner for reading out a linear object as an image signal, and two linear light sources arranged in an elongated line at predetermined positions symmetrical with respect to the photoelectric conversion scanner. A light source switching circuit for controlling whether one of the linear light sources is turned on, an A / D conversion circuit for converting an image signal read by the photoelectric conversion scanner into a digital image, An image memory circuit for separately storing a digital image in a state in which only one of the shape light sources is turned on and a digital image in a state in which only the other is turned on, and a difference image between the stored two images. A difference image calculation circuit to be obtained, an addition circuit to obtain an added image between the two stored images,
The position of the shadow generated by each linear light source is detected, and the position of the target linear shape is detected from the addition signal output from the addition circuit. The detected shadow and the target position are separately labeled according to the connection relation. Labeling circuit that performs numbering, and corresponding points based on the corresponding positional relationship determined by the position of the pre-arranged photoelectric conversion scanner and linear light source of the shadow and target by scanning the label signal with the label number in the horizontal direction A three-dimensional shape calculating circuit that calculates a three-dimensional shape by calculating a three-dimensional coordinate position from the detected corresponding positional relationship;
An apparatus for determining a line shape, comprising: a shape determination circuit that determines the acceptability of a shape using a determination reference value preset from a dimensional shape.