JPH04310816A - Optical apparatus for measuring distance - Google Patents

Abstract

PURPOSE:To obtain an optical apparatus for measuring distance which makes it possible to measure many points simultaneously and with a high resolution maintained. CONSTITUTION:This apparatus comprises a fixed camera 2 disposed oppositely to an object 1 of measurement and a beam projecting system 3 projecting a diffused beam to the object of measurement, and the fixed camera 2 has an arithmetic means which calculates a distance to each area by catching the size of the beam 71 projected to a prescribed area on the object 1 of measurement and by subjecting it to an image processing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical distance measuring device for calculating the orientation of an object to be measured from an image of the object captured by a camera or the like.

0002

2. Description of the Related Art When considering a system in which an object to be measured, such as a human image, is captured by a TV camera and the posture of the person is recognized using means such as image processing, this is because the captured image information is two-dimensional information. It is difficult to recognize the posture by looking at the image alone. Therefore, distance information for each part of the person to be measured is required.

By the way, various methods have been proposed for measuring the distance of an object to be measured, including methods using an ultrasonic distance meter or a laser length measuring device, for example.

However, the former method lacks spatial resolution, and the latter method has problems in simultaneous multi-point measurement and the apparatus itself becomes complicated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the conventional methods described above, and an object of the present invention is to provide an optical distance measuring device that can measure multiple points simultaneously while maintaining high resolution. The purpose is to

[0006]

[Means for Solving the Problems] The present invention comprises a fixed camera disposed facing an object to be measured, and a beam projection system that projects a diffused beam onto the object to be measured, The fixed camera is characterized in that it has a calculation means that calculates the distance to each region by capturing the size of the beam projected onto a predetermined region on the object to be measured and performing image processing on this. It is an optical distance measuring device.

[0007]

[Operation] The beam emitted from the beam projection system is projected onto the object to be measured, and the object to be measured is taken into the fixed camera together with the projected beam. The distance from the beam captured in this way to the area onto which the beam is projected is calculated via the calculation means, and information on the image and orientation of the object to be measured is obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical distance measuring device of the present invention will be described in detail below with reference to one embodiment of the drawings.

FIG. 1 is a schematic diagram showing the system configuration of an optical distance measuring device, in which 1 is an object to be measured, and 2 is a device which has a built-in calculation means 21 for image processing and is arranged opposite to the object to be measured. A fixed camera 3 projects a beam of a size corresponding to the separation distance onto the object 1 to be measured.
4 is a condenser lens disposed between the object to be measured 1 and the fixed camera 2; 5 is a half mirror disposed between the condenser lens 4 and the fixed camera 2; be.

In FIG. 1, the angle of view of the fixed camera 2 is within the range indicated by the largest outer triangle 6, and the beam projection system 3 is located outside of this triangle 6. 2 so that the beam projection system 3 does not enter there. For this reason, the beam 7 emitted from the beam projection system 3 is reflected on the surface of the half mirror 5, its optical path is bent, and the beam is focused by the condenser lens 4 about 2 m in front of the object to be measured 1. A beam that spreads according to the distance to each part of the object to be measured and whose size changes in each part of the object to be measured is formed by connecting the
The settings are made so that the image 71 can be obtained.

It is possible to use visible light or infrared light as the beam 7, but if the object to be measured is a person, it is preferable to use infrared light, which has less influence on the human body. Furthermore, since it is difficult to measure if the angle of view 6 of the fixed camera 2 is the same as the angle of diffusion of the beam 7, it is desirable that the angle of view 6 be as different as possible.

When using the optical distance measuring device having the above configuration to capture information on the image and orientation of the object to be measured, first the fixed camera 2 and the beam projection system 3 are activated, and the beam projection system 3 is activated. 71 and information on the image of the object 6 are simultaneously captured into the fixed camera 2.

FIG. 2 shows an image of a person as the object to be measured 1 captured by the fixed camera 2. As shown in FIG. In this portrait,
Determine the distance of the object as follows.

[0014] First, it is assumed that the contour of the person has been extracted in advance.

(2) When a spot light is irradiated onto a person, it is easy to extract only the spot from the image because the laser irradiated area has extremely high brightness compared to the surrounding area.

[0016] Here, brightness threshold processing is performed to extract parts having a brightness above a predetermined value.

■ Spots that come into contact with the outline of a person are excluded because they have a large error.

■ Measure how many pixels the area of each spot is on the screen. At this time, since the surface of the person is not completely flat, the circular spot will be distorted, but this is not a problem since high precision is not required.

[0019] ■ Compare the number of pixels obtained in the above (■) with the corresponding data of the number of pixels and distance created in advance,
Estimate the distance to each spot.

In this way, the area around the right hand 11 is the left hand 12.
Spot 72 on the person's surface, which is closer than the surrounding area
It can be seen that the spot 73 is projected smaller than the spot 73. Also, if you look at the left foot, you can see that the spot size gradually decreases from spot 74 to spot 76.
You can see that it is closest near the knee and gradually gets farther away towards the ankle. Furthermore, the head, chest, and right foot are spot 77 on the surface.
79 are approximately the same size, it can be seen that each part exists approximately at the same distance from each other. Therefore, by measuring the spot size of each part using image processing, relative distance information of each part of the person can be obtained at the same time. By combining this distance information with the information of the two-dimensional image captured by the fixed camera 2, information for recognizing the posture of the person can be obtained.

The circular spot beams 72 and 73 as shown in FIG. 2 may be obtained by using, for example, a plurality of semiconductor lasers L1 arranged in a matrix as shown in FIG. As shown in the figure, the beam of one semiconductor laser L2 is
This can be easily obtained by splitting the beam into a large number of beams using an optical fiber F and removing the diffused light through a slit S.

FIG. 5 shows a case where a linear beam is used instead of the circular spot. In this case, beam 8
It is possible to recognize a person along with their posture in the same manner as in the example of FIG. 2, except that distance is expressed by differences in the widths of the images.

The linear beam 8 as shown in FIG. 3 can be easily formed by scanning with a polygon mirror of semiconductor lasers arranged in a line, or by using a means such as a cylindrical lens C as shown in FIG. can be created. That is, as shown in FIG. 7, of the laser beams passing through each cylindrical lens C, only the beams passing in the direction of curvature are refracted in the optical path to form a line-shaped beam B.

[0024]

Effects of the Invention As described above, the present invention consists of a fixed camera placed facing the object to be measured, and a beam projection system that projects a diffused beam onto the object to be measured. ,
The fixed camera has a calculation means that calculates the distance to each area by capturing the size of the beam projected onto a predetermined area on the object to be measured and performing image processing on it. An optical distance measuring device capable of measuring distances at multiple points simultaneously without reducing resolution can be obtained using an extremely simple method.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of an optical distance measuring device according to the present invention.

FIG. 2 is a plan view showing an example of an image using circular spots.

FIG. 3 is a diagram showing an example of an apparatus for creating a circular spot.

FIG. 4 is a diagram showing another device for creating a circular spot.

FIG. 5 is a plan view showing an example of an image using a line-shaped beam.

FIG. 6 is a diagram showing an apparatus for creating a line-shaped beam.

FIG. 7 is an enlarged view of FIG. 6.

[Explanation of symbols]

1 Measurement object 2 Fixed camera 3 Beam projection system 7 Beams 71 to 79 Spot beam 8
line beam

Claims (1)

[Claims] 1. The fixed camera includes a fixed camera disposed facing the measurement object, and a beam projection system that projects a diffused beam onto the measurement object. An optical distance measuring device characterized by comprising a calculation means for calculating the distance to each of the above predetermined areas by capturing the size of the beam projected onto the above predetermined areas and performing image processing on the size of the beam.