JPH02176410A - Distance-image obtaining apparatus - Google Patents

Abstract

PURPOSE:To decrease areas, which cannot be measured, even in only one measurement by simultaneously projecting a plurality of spectral patterns having specified wavelengths on a body, and picking up the actual image with a plurality of sensors having sensitivities only for the specified wavelengths. CONSTITUTION:The wavelength regions of the spectral patterns of spectral pattern projecting devices 32 and 33 are lambda1-lambda2 and lambda3-lambda4, respectively. The projecting devices 32 and 33 are used, and the spectral patterns are projected on a body 2 at the same time. The actual image is picked up by a camera 31. Sensors 24 and 25 housed in the camera 31 have sensitivity only for the wavelength region of the spectral pattern projecting device 32. Sensors 26 and 27 have sensitivity only for the wavelength region of the projecting device 33. The outputs of the sensors 24-27 are independently processed in distance image computing parts 34 and 35. The distance images are stored in a memory 39. Therefore, areas which cannot be measured can be decreased even in only one measurement. The apparatus can be effectively used for picking up the image of a part of a human body where pain is felt.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distance image acquisition device used in a stereoscopic measurement device.

[Conventional technology]

A distance image acquisition device has been proposed as a device for determining the three-dimensional position of an object, etc. from an image input from a television camera (Japanese Patent Application Laid-open No. 195379/1983). An example of a method for determining the distance will be briefly explained with reference to FIG.

The image data acquired by the two sensors 5 and 6 having different spectral sensitivities σ and σ2 of the camera 3 are transferred to the A/D converter 7,
8, the ratio R is calculated for each pixel of the two image memories 9 and 10 according to the following equation, and the ratio image is stored in the ratio image memory 12.

However, when the first calibration image is obtained by placing a white board on the output plane 19 of the pixel of the sensor 6 where the point P is imaged, Function operation section 1
4 is a function X of the ratio R in the plane 19 from the ratio image stored in the ratio image memo 1j12 via the switch 13;
Find and hold (R). The function X, (R) has a value in the observed range of Rat≦R≦R1. Similarly, plane 2
When a second comparison image is obtained by placing a white board at
The function xi(R) of the ratio R in the plane 20 is obtained from the ratio image stored in 2 and held. Function X, (R)
has a value in the range of Rbl≦R≦Rb2.

The diffraction position calibration unit 16 uses functions X, (R) and X5
For (R), for the overlapping part of the domain of both R, using an appropriate constant C according to equation (2), (X,
, Z, ) and (X, , Z,) are determined, and the diffraction positions (Xo, Zo) are determined using equations (3) and (4). The calibrated diffraction positions (Xo, Zo) are transferred to the diffraction position calibration unit 1.
It is held at 6.

Z = a RX + b n (R = R1r R21・
・・・）・・・・・・(3) ・・・・・・(4) When measuring the distance to the actual object 2, the actual scene is obtained in exactly the same way in the image memories 9 and 10, and the ratio image is The ratio image is obtained in the image memory 12. The distance calculation unit 17 outputs the ratio R for each pixel from the ratio image memory 12 to the switch 13 along with the X coordinate value.
The diffraction positions (xo, ze) read out through the diffraction position calibration unit 16 and the function calculation unit 14.15E
Using the retained functions X, (R), and Xb(R), the distance 2 is determined by equation (5) or equation (6) and written into the distance image memory 18.

As a result of the above series of operations, the distance 2 from the camera 3 to the object 2 is obtained in each pixel of the distance image memory 18.

[Problem to be solved by the invention]

According to the conventional technology described above, two or more measurements are required to reduce the area where distance measurement is impossible due to blind spots in the spectrum pattern. For example, in FIG. 9, region A is visible from the camera and a spectral pattern is projected thereon, so it can be measured. However, although region B is visible from the camera, it cannot be measured because no spectral pattern is projected. In order to measure both areas A and B, it is necessary to rotate the object or rotate the camera and the projection device and perform measurements two or more times, which takes time.

This becomes a problem especially when measuring objects such as human bodies that are difficult to maintain a constant posture for long periods of time.

An object of the present invention is to provide a distance image acquisition device that can reduce unmeasurable areas caused by blind spots in a projected spectral pattern by measuring only once without performing mechanical scanning.

[Means to solve the problem]

The distance image acquisition device of the present invention includes: a plurality of spectral pattern projection means for projecting spectral patterns in wavelength ranges specific to each direction from multiple directions onto an object; a camera for photographing the object; A plurality of sensor sets having sensitivity only in the same wavelength range as the unique wavelength range of each of the plurality of spectral pattern projection means, and a plurality of distance image calculation means for calculating a distance image using image data obtained from each of the sensor sets. a plurality of distance image memories for storing distance image data obtained from each of the distance image calculation means; a distance image data integration means for integrating the contents of each of the plurality of distance image memories into one screen; and a distance image data integration means. It has a distance image memory for storing data output from the means.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

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

In the figure, the spectral pattern projection devices 32 and 33 are
Spectral patterns of wavelengths λ1 to λ2, λ, and ˜λ are simultaneously projected onto the object 2, respectively. However, λ2 times λ. The object 2 is photographed by the camera 31, and the light branching element 2
Sensors 24, 25, 26, 27 via 8, 29, 30
Tie a statue on top. Sensors 24, 25 and sensors 26, 27
The image data obtained from the is input to the distance image calculation units 34 and 35, respectively, to calculate a distance image, and the results are recorded as a distance image memo! Store in J36 and J37, respectively. Distance image memo! The data of J36 and J37 are integrated into one screen by the integration processing unit 38, and the result is stored in the distance image memory 39.

Next, the operation of the distance image acquisition device shown in FIG. 1 will be explained with reference to FIGS. 2 to 7. The wavelength ranges of the spectral patterns projected from the spectral pattern projection devices 32 and 33 are λ1 to λ2, λ, to λ4, respectively (λ2<λ
,). The object 2 is simultaneously irradiated using the spectral pattern projection devices 32 and 33, and the actual scene is photographed by the camera 31. Sensors 24, 25, 2 built into the camera 31
6.27 is the spectral sensitivity σ3.h as shown in FIGS. 2, 3, 4, and 5, respectively. σ4. σ5. It has σ6.

As is clear from the figure, the sensors 24 and 25 are sensitive only to the wavelength range of the spectral pattern projection device 32,
Sensors 26, 27 are sensitive only to the spectral pattern projection device 330 wavelength range. Therefore, the sensors 24 and 25 detect only the spectrum pattern projected from the spectrum pattern projection device 32, and the sensor 26 detects only the spectrum pattern projected from the spectrum pattern projection device 32.
, 27, only the spectral pattern projected from the spectral pattern projection device 33 is detected, so that the spectral patterns from the other projection devices are not detected. Therefore, the outputs of the sensors 24 and 25 and the outputs of the sensors 26 and 27 are independent of each other, based on the known fact (Japanese Unexamined Patent Publication No. 62-19537
90) in the distance image calculation units 34 and 35, and each distance image can be obtained as follows.

First, prior to actual measurement, the diffraction position of the spectral pattern is determined. In FIG. 6, the camera 31 has different spectral sensitivities σ1. The image data acquired by the sensor of σ4 is A
/D converters 7, 8 to two image memories 9 and 1o
The ratio R is calculated for each pixel according to equation (1), and the ratio image is stored in the ratio image memory 12.

When a white board is placed on the plane 19 and the first calibration image is acquired, the function calculation unit 14 calculates the function x of the ratio R on the plane 19 from the ratio image stored in the ratio image memory 12 via the switch 13. Find and hold t(R). Function X-
+(R) has a value in the range of observed R, □1≦R≦R11□. Similarly, when a white board is placed on the plane 2o and a second calibration image is acquired, the function calculation section 15 uses the ratio image stored in the ratio image memory 12 via the switch 13 to calculate the ratio R on the plane 2o. Find the function Xb+(R),
Hold. The function x b+ (R) is R61, ≦R≦R
It has a value in the range of bl□.

The diffraction position calibration unit 16 calculates the functions X, l (R) and Xb
For l(R), for R in the overlapped domain of both R, using an appropriate constant C according to equation (2), (X
,,Z,), (X,,Z,), and calculate the diffraction position (X o+ , Z o+) using equations (3) and (4).
seek.

The calibrated diffraction positions (Xo+, Zo+) are held in the diffraction position calibration section 16.

Next, the diffraction position (X,
,,Z,2) is found. In this case as well, the above-mentioned diffraction position (X
o+, Zo+), σ8.
σ4. X, +(R), Xbl(R), R,ll,
R, 12°Rb + + + Rb + t r X
a + r Z o 1, respectively, σ5+ σ8+
X, 2(R), Xbz(R), R-21, R-2
□r Rb2z Rb22°XO2, z02 can be obtained in exactly the same way.

After determining each diffraction position in this manner, distance image measurement of the actual object 2 is performed.

When measuring the distance to the actual object 2, the camera 31 has different spectral sensitivities σ1. The image data of the actual scene acquired by the sensor σ is obtained from the A/D converters 7 and 8 to the image memories 9 and 10, and the ratio image is obtained to the ratio image memory 12. The distance calculation unit 17 reads out the ratio R for each pixel together with the X coordinate value from the ratio image memory 12 via the switch 13,
The diffraction position (Xo+
, Zoo) and the functions X, 1(R), 36
write to.

As a result of the above series of operations, the distance 2 from the camera 31 to the object 2 is obtained in each pixel of the distance image memory 36.

Next, the different spectral sensitivities σ1 of the camera 31. The image data acquired by the sensor σ6 is σ, as described above.

In the explanation of the image data acquired by the σ4 sensor, (Iss (141XIIIJ Zoo, x, +
(tt).

x b 1(R), distance image memory 36 respectively σ6
．． σ6゜X@2. Z6! , X-z(R), Xb2
(R), just read it as distance image memory 37, and it is processed in parallel in exactly the same way.

Now, the distance images obtained in the distance image memories 36 and 37 measure the distance to the area A21 and area B22, respectively. In the integrated processing unit 38, the distance image memory 3
The pixel value, that is, the measured distance, is read out for each pixel of 6 and 37, and the presence or absence of the measurement value is determined by the measurement value presence/absence determining unit 40. If there is a measurement value, the value is stored in the distance image memory 39. Forward. At this time, the area C that was measured redundantly
As for the distance 42, an average value is calculated by an average value calculation unit 41, and the result is transferred.

As a result of the series of operations described above, a distance image in which unmeasurable areas caused by blind spots in the spectral pattern are reduced is obtained in the distance image memory 39 with only one measurement.

Note that in the above example, the case where there are two sets of spectral pattern projection devices and corresponding sensor sets has been explained.
It is clear that the same procedure can be easily carried out in the case of three or more groups, and the same effect can be obtained.

〔Effect of the invention〕

As explained above, the present invention simultaneously projects spectral patterns specific to each device onto an object from different directions using a plurality of spectral pattern projection devices, and displays the actual scene with sensitivity only to the wavelength range specific to each spectral pattern. By simultaneously capturing images with multiple sensor sets and calculating a distance image using the image data, the occurrence of blind spots in the spectral pattern is reduced even when measuring only - times, and as a result, it is possible to eliminate areas that cannot be measured. It has a mitigating effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG.
Figures 3, 4, and 5 are examples of the spectral sensitivity of the sensor shown in Figure 1, Figure 6 is an example of the block diagram of the distance image calculation section shown in Figure 1, and Figure 7 is the An example of a block diagram of the integrated processing unit shown in FIG. 1, FIG. 8 is an explanatory diagram of the conventional technology, and FIG. 9 is an explanatory diagram of the problem to be solved by the invention. 1.32.33...spectral pattern projection device, 2...object, 3,31...camera,
5,6,24゜25.26.27...Sensor,
7. Death------A/D converter, 9, 10...
・Image memory, 11... Ratio image calculation section, 12.
... Ratio image memory, 13 ... Switch,
14.15...Function operation section, 16...
Diffraction position calibration unit, 17...Distance calculation unit, 18,
36°37.39・・・Distance image Gumori, 19.
20... Plane, 21... Area A122
......Area B, 23...Camera field of view, 4
．． 28, 29.30... Optical branching element, 34.3
5...Distance image calculation unit, 38...Integration processing unit, 40...Measurement value presence/absence determination unit, 41...
...Average value calculation department, 42...Area C0 agent Patent attorney Shinka Uchihara ■ Broom drawing Seri-kuho! Sheep tea ceremony 9 times

Claims (1)

[Claims] A distance image acquisition device that projects a separated spectral pattern onto an object, captures this image with a camera having sensors with different spectral sensitivities, and calculates the distance to the object for each pixel, comprising: The spectral pattern of the wavelength range specific to each direction is
a camera comprising: a plurality of spectral pattern projection means that simultaneously project images onto an object; a plurality of sensor sets that are sensitive only to specific wavelength ranges of each of the plurality of spectral pattern projection means; A plurality of processing means corresponding to each sensor set that calculates the distance to an object from the output of the plurality of sensor sets, and an integrated processing means that integrates a plurality of distance images obtained from the plurality of processing means into one distance image. A distance image acquisition device characterized by: