WO2004094944A1

WO2004094944A1 - Method and apparatus for measuring distance

Info

Publication number: WO2004094944A1
Application number: PCT/JP2003/005211
Authority: WO
Inventors: Seijiro Tomita
Original assignee: Seijiro Tomita
Priority date: 2003-04-23
Filing date: 2003-04-23
Publication date: 2004-11-04
Also published as: AU2003231457A1; JPWO2004094944A1

Abstract

A method and an apparatus for measuring the distance capable of determining the correct position of an object only from information attained by means of two imaging units, characterized in that the object is photographed by two imaging means each comprising an imaging element and having an optical axis crossed at a specified cross point (convergence point: CP), coordinates of the identical object photographed by the imaging elements of two imaging means are determined on the imaging element, and the distance from the imaging position to the object is operated from information acquired by a coordinate acquiring means.

Description

Specification '

Distance measuring method and device

Technical field

The present invention relates to a method and an apparatus for measuring a distance, and in particular to an image pickup device provided with an image pickup device, and an image obtained by photographing an object by two image pickup means having optical axes crossed at a predetermined cross point (compare ence point: CP). The present invention relates to a distance measuring method and apparatus capable of accurately measuring the distance from a camera to a subject by processing.

BACKGROUND ART Conventionally, three-dimensional image information is obtained by imaging an object (subject) using a plurality of imaging means, for example, a camera, and is displayed as a real image according to human visual characteristics. That is being done.

One of them is the binocular parallax method. In the binocular parallax method, imaging is performed by setting the base line length of the naked eye (for example, 72 mm) and setting each value in consideration of the visual field convergence angle range of the naked eye.

Then, when displaying these images, an appropriate parallax (lateral displacement of the image) is given according to the distance and the shape to the object recognized by the observer.

For this reason, it is necessary to change the displayed image according to changes in the camera shooting position and the observer's viewpoint position during shooting.

Furthermore, when the same content is played back on display devices having different screen sizes, if the parallax between the left and right images is different, the amount of projection from the screen changes depending on the screen size, and a natural stereoscopic image cannot be obtained.

In other words, stereoscopic video content intended for large-scale entertainment facilities is produced with the assumption of a large screen size on which the content will be screened. When the screen size was too large, the stereoscopic effect was too strong to give an uncomfortable feeling. In addition, when the screen size was small, the stereoscopic effect was small and unsatisfactory.

Also, since such content is a splice of various scenes, Since the shooting conditions of the scene, the focal length of the lens of the shooting unit, and the distance between the two shooting units are not always the same, simply joining such scenes will give different stereoscopic effects in one content. Was displayed, giving the viewer a sense of incongruity and physical discomfort.

Furthermore, the positional relationship between the stereoscopic video imaging and display system and the observer is not always constant, and the observer is not always located at the position intended by the content creator, and the observer is displaced from the predetermined observation position of the stereoscopic video device. In this case, the creator cannot observe the intended image.

For this reason, when producing stereoscopic video content, the screen size (display or screen size) to be finally displayed is assumed, and the cross-points of the shooting stereo camera (compare en- gage points: CP) and computer graphs are produced by adjusting the amount of parallax, but once the content is produced, the stereoscopic effect will differ if the screen size of the stereoscopic video shooting and display system changes. Accordingly, it was necessary to produce a stereoscopic image again. In addition, when creating a stereoscopic image using CG (Computer Graph ics), rendering and the like had to be performed again.

Further, in the above-described conventional example, since the image is simply displayed with the camera arrangement at the time of imaging, when an observer changes the viewpoint position with respect to the same object, a newly generated shielding unit or an original shielding unit is formed. It was not possible to generate an image that correctly reflected the part that was not visible and that was visible for the first time, and was unable to convey the image intended by the creator to the viewer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional technology, and measures a distance at which a correct position of an object can be reliably obtained with only information obtained by two imaging devices. It is an object to provide a method and an apparatus.

Disclosure of the invention

The present invention according to claim 1 includes two image pickup means each having an image sensor and crossing the optical axis at a predetermined cross point (comparence point: CP). An object is photographed, coordinates of the same object photographed by the image pickup devices of the two image pickup devices are obtained on the image pickup device, and a distance from the image pickup position to the object is calculated from the information acquired by the coordinate acquisition device. This is a method for measuring the distance. ADVANTAGE OF THE INVENTION According to this invention, the position to an object can be calculated | required accurately and easily from only the image information based on two imaging means.

According to a second aspect of the present invention, there is provided the distance measuring method and the distance measuring device distance according to the first aspect, wherein the calculation of the distance includes a table means provided with an output value for an input value in advance. This is characterized by performing the above. According to the present invention, an output value can be obtained immediately with respect to an input value, so that the calculation speed can be increased quickly, and it is not necessary to use a high-speed calculation means.

According to a third aspect of the present invention, in the method for measuring a distance according to the first aspect, an aberration inherent in the optical element of the imaging unit is corrected. According to the present invention, a proper position can be measured by knowing in advance the inherent aberrations of a lens or the like and correcting them.

According to a fourth aspect of the present invention, there is provided the distance measuring method according to the first aspect, wherein the correction of the aberration of the optical element includes a table having an output value with respect to an input position of the optical element in advance. It is characterized by using means. According to the present invention, a correction value for an input value is immediately output without requiring any arithmetic processing. According to a fifth aspect of the present invention, in the distance measuring method according to any one of the first to fourth aspects, the calculation of the distance and the correction of aberration of the optical element are the same table. It is characterized by using means. According to the present invention, the calculation of the distance for one value and the correction of the aberration of the optical element can be performed in one table, and each calculation can be corrected quickly, and the calculation and correction are required. The number of devices can be minimized.

According to a sixth aspect of the present invention, there are provided two image pickup units each including an image pickup element, wherein the optical axes are crossed at a predetermined cross point (compare entrance point: CP); Coordinate acquisition means for obtaining coordinates on the image sensor of the same object photographed by both image sensors; and arithmetic means for calculating the distance from the imaging position to the object from the information acquired by the coordinate acquisition means. A characteristic distance measuring device You. ADVANTAGE OF THE INVENTION According to this invention, the position to an object can be calculated | required accurately and easily from only the image information based on two imaging means.

According to a seventh aspect of the present invention, in the distance measuring device according to the sixth aspect, the distance calculation includes a table unit having an output value for an input value in advance. Is what you do. According to the present invention, an output value can be obtained immediately with respect to an input value, so that the calculation speed can be increased quickly, and it is not necessary to use a high-speed calculation means.

The present invention described in claim 8 is characterized in that it comprises an aberration correcting means for correcting an inherent aberration of the optical element of the distance measuring method imaging means according to claim 7. According to the present invention, a proper position can be measured by knowing in advance the inherent aberrations of a lens or the like and correcting them.

The present invention described in claim 9 is the distance measuring device according to claim 5, wherein the aberration correcting means is a table means provided in advance with an output value corresponding to the position of the input optical element. It is characterized by having. According to the present invention, a correction value for an input value is immediately output without requiring any arithmetic processing.

According to a tenth aspect of the present invention, in the distance measuring device according to any one of the sixth to ninth aspects, in the distance, the arithmetic unit and the aberration correction unit of the optical element are the same table unit. It is characterized by the following. ADVANTAGE OF THE INVENTION According to this invention, calculation of the distance with respect to one value and correction | amendment of the aberration of an optical element can be performed with one table, and each calculation correction | amendment can be performed quickly, and calculation and The number of devices required for collection can be minimized.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing an embodiment of a distance measuring device according to the present invention. FIG. 2 is a flowchart showing a processing flow in the distance measuring device shown in FIG.

FIG. 3 is a block diagram showing a distance measuring device according to the present invention.

FIG. 4 is a diagram showing a state of distance measurement according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a system configuration diagram showing an embodiment of the present invention. In Figure 1, 1 τ., 1 p is Left camera and the right camera is an imaging means, 2 have 2 _R image pickup device of the right and left mounted on the camera 1 _L, 1 _R, for example, C CD is an element, in 1 5 1 each lateral direction (y-direction) Two light receiving elements (756 each from the center lines C _R and C _L ) are provided.

In this example, each camera is arranged at a distance of S / 2 (for example, 36 mm, or 10 cm) from the center O (0, 0) of the reference axis (xy axis), and their optical axes ( CL, CR) intersect at the cross point CP (C, 0) 1 m away. In this example, the target object P is located at the position (L, Δγ).

Reference numeral 3 coordinate acquisition means for acquiring a coordinate position which receives the object point Ρ-receiving element 2 have 2 _R, reference numeral 4 is aberration for correcting the aberration of the optical element such as a lens which comprises said image pickup means 1 1 _R 2 shows a capturing means. This aberration includes so-called Seidel's five aberrations.

Reference numeral 5 denotes a calculating unit that receives outputs of the coordinate obtaining unit 3 and the aberration correcting unit 4 and finally calculates a distance L to the object point P and a distance Δy to the optical axis O. . Next, processing of the distance measuring device according to the present example will be described. In this example, photographing by photographing means (Sl), acquisition of coordinates by both image sensors (S2), correction of optical element aberration (S3), and calculation and output of L and Ay by this (S1) S 4).

Figure 3 shows a more specific configuration. In this example, the coordinate acquisition means 3, the aberration correction means 4, and the calculation means 5 have a calculation processing unit 11 and a table 12 storing lens aberration correction data and Ay calculation data.

Then, the L and Ay calculated by the arithmetic processing unit 11 and the image data captured by the CCD image sensors 2 L and 2 R are transmitted to the stereoscopic display device 22 via the stereoscopic image display processing device 21. Is displayed three-dimensionally.

Next, the calculation of the distance L and Δy in the present invention will be described with reference to FIGS. Here, f in the figure represents the focal length of the lens of the imaging means.

For the left camera, the following equation holds.

y _L p / {(A y / cos 0 _L ) + [(m z—m ytan 0 _L ) si η Θ J} = f / {(zc / cos Θ-[(A z—A ytan 0 _L ) sin {J} (Equation 1) The same equation holds for the expression of the right camera. And

If the camera is fixed with 0 _L = 0 _R = e, Equation 1 becomes simple as follows.

y _LP / {(A y / cos 0) + [(m z m ytan 0) si η Θ]} = f / {(zc / cos 0)-[(m z -m ytan 0) sin Θ]}} equation 2) 4 than the triangle f, y, _p, since it is O _y and triangle f PQ similar ,,

y _LP / 'A' = f / 'B'.

Where Ά '= Ό' + 'd'

'Β' = 'e'-Divide as 'f' and derive 'c' 'd' 'e' 'f, c' = (m y / cos Θ)

d '= (Δ ζ -Δ y t a n Θ) / s i n Θ

e = (z c / c o s Θ)

f '= (Δζ-Δγΐ Β ηθ) · cos Θ.

Substituting c 'to' f 'into y _L /' A '= f /' B 'gives

y _LP / {(m y / cos 0) + [(m z—A ytan 0) sin θ]} = f / {(zc / cos Θ)-[(m z m ytan 0) cos 0]} (expression 3) It is only necessary to calculate Δz and Δy from these two equations (Equation 2 and Equation 3).

Here, t an A is a constant that is the angle of view of the camera, and can be obtained in advance by calculation and measurement. In addition, the following numerical value 756 is the number of elements from the center of the CCD image sensor to the left and right edges, and this value changes the number of elements of the image sensor and the starting point of calculation (for example, changing the starting point to the left end Can be changed as appropriate.

Also,

'R' is

[(M z + A ytan 0) sin 0— (m V / cos Θ)] I then {z / co S Θ— [, m Z + A ytan 0) / cos 9]} tan A3 = + x _R / 756

'

[(Δ ζ m ytan 0) sin 0 + (m y / cos 0)] / C {z / cos Θ-[(m z—

y.)} A0 // tapo9cstx756anA. + = 'P' = -756-tan 9-sin 0+ C (756- x _L · ί α η θ · ί η Α) / ο ο 3 θ]

{[One 'Q'-m z + 'R' x _R (z _ m z)] I '0'} = {[-'Q'-m z + 'R' x _L (z-m z)] I 'Ρ'}

-'Q,' Ρ 'Δ ζ +' R, 'Ρ' x R · z-'R''P' x _R · Δ z =-'Q''0'. Mm z + <0 'R' x _Lz -'0''R' x _L

(- ^£ Q '' P, — 'R,' P '. X _R +' 0 '' R 'x _L +' Q '' 0 ') Δ z = + <0,' R '-' R '' P 'x _R .z = (' 0 '' R, x _L- 'R''P' x _R ) z

'S, =-' Q '' P '' R '' P,. X R + '0''R' x _L + 'Q'<0,

'0' = '0''R' x _L- 'R''P, x R

here,

X _R and _XL are the amount of image shift

z is the cross point

What we want is Δ z.

'R' is calculated by the following equation.

756 (A z + A ytan 0) sin 0 _ [(756 · Αγ) /. ο 3 θ] = [(ζ · χn A) / cos Θ]-{[x _R (A z + A ytan 0) tan A] / cos Θ}

756 · m z + [(x _R · tan A) / cos] · m z = [(z · x _R -tan A) / co — [(x _R -A ytan 0 · tan A) / cos Θ] — 756 · m y · tan Θ · s ten [(756 · Δ y) / cos 0]

{(756 · cos Θ + x R · tan A) / cos θ} Δ z = (z · x R · tan A- x R · tan Θ · tan A-756 ·厶y · sin ² 0 +756 · Δ y) / cos Θ

Is calculated by the following equation. 756 (Λ z -Δ ytan θ) sin Θ + C (756-A y) / cos 9] = [(z-x _L -tan A) / cos Θ]-{(x _L (A z m ytan Θ) tan A] / cos Θ}

756 -厶_{z + C (x L · tan} A) / cos θ ] · delta z = _{[(z · x L - tan A} ) / cos Θ] + [(x L - A ytan 0 · tan A) / cos Θ] —756 'A y' tan Θ · sin Θ-[(756 · Δ y) / cos Θ]

{(756 · cos Θ + x L · tan A) / cos Θ} A z = (z · x L · tan A + x L · Δ y · tan Θ · tan A-756 · Δ y · sin 2 Θ +756 · Mm y) / cos 0 Calculate Δ y from the basic formula. Note that Δy is the amount of deviation from the center in this example.

_{(Z · X R · tan Ax} "· A y - tan θ · tan A-756 · Δ y · sin 2 Θ +756 · Δ y) / C (756 · cos Θ) + (x R · tan A)] _{= (z · x L · tan} A + x L · Δ y · tan Θ · tan A + 756 · A y · sin 2 Θ -756 · A y) / [(756 · cos Θ) + ( x L · tan A)]

_{[Z · x R · tan A +} (-x R · tan Θ · tan A-756 sin 2 Θ +756) Δ y ] I 'V = _{[z · x L · tan A +} (x L - tan Θ · tan A + 756 sin ² Θ -756) Δ y) / 'M'

_{L '= (z · x R} · tan A- x R · A y · tan Θ · tan A-756 · A y · sin 2 Θ +756' A y) / [(756 · cos Θ) + ( x R · Tan A))

'M, = (z · x L · tan A + x L' A y 'tan Θ · tan A + 756 ·厶^{y · sin 2 Θ - 756 ·} A y) / C (756 - cos 0) + (x _L -tan A)]

_{'N' = -x R · tan} Θ · tan A-756 sin 2 Θ +756

_{'0' = x L · tan} Θ · tan A + 756 · sin 2 Θ - 756

'Q = z-χ „t a n A

'R' = zx _L -tan A M, 'Q' + 'M,' N, m y = 'L''R' + 'L' Ό 'Δ y

{'M' 'N'-'J' Ο '} A y = (' 'R'-'Μ' 'Q')

Δ y = <S, I 'Τ'

As a result, the distance L to the object point and the shift Δy in the left-right direction are obtained from the images of the left and right imaging elements.

In this example, by storing this result in a table in advance, the values of L and Δy can be output instantaneously from the time of image acquisition.

In addition, the table can store in advance the correction amount of the aberration for the optical element, and this value can be appropriately changed according to the correction amount of the lens used.

Industrial applicability

The present invention described in claim 1 provides an image pickup device, each of which includes an image pickup device, and images an object by two image pickup units whose optical axes are crossed at a predetermined cross point (compare ence point: CP). Determining a coordinate on the image sensor of the same object photographed by the image sensor of the imaging means, and calculating a distance from the imaging position to the object from the information acquired by the coordinate acquisition means. It is. ADVANTAGE OF THE INVENTION According to this invention, the position to an object can be calculated | required accurately and easily from only the image information based on two imaging means.

According to a second aspect of the present invention, in the distance measuring method and the distance measuring device distance according to the first aspect, the distance calculation includes a table in which output values for input values are provided in advance. It is characterized by using means. According to the present invention, an output value can be obtained immediately with respect to an input value, so that the calculation speed can be increased quickly, and it is not necessary to use a high-speed calculation means.

According to a third aspect of the present invention, in the distance measuring method according to the first aspect, an inherent aberration of the optical element of the imaging unit is corrected. According to the present invention, a proper position can be measured by knowing in advance the inherent aberrations of a lens or the like and correcting them. According to a fourth aspect of the present invention, there is provided the distance measuring method according to the first aspect, wherein the correction of the aberration of the optical element includes a table means which is provided in advance with an output value corresponding to a position of the input optical element. This is characterized by performing the above. According to the present invention, a correction value for an input value is immediately output without requiring any arithmetic processing. According to a fifth aspect of the present invention, in the distance measuring method according to any one of the first to fourth aspects, the calculation of the distance and the correction of aberration of the optical element are the same table. It is characterized by using means. ADVANTAGE OF THE INVENTION According to this invention, calculation of the distance with respect to one value and correction | amendment of the aberration of an optical element can be performed in one table, and each calculation correction | amendment can be performed quickly, and calculation and capture are possible. The number of devices required can be minimized.

According to a sixth aspect of the present invention, there are provided two image pickup means each including an image pickup element, wherein the optical axes are crossed at a predetermined cross point (compare-enforcement point: CP); and Coordinate acquisition means for obtaining coordinates on the image sensor of the same object photographed by both image sensors; and arithmetic means for calculating the distance from the imaging position to the object from the information acquired by the coordinate acquisition means. This is a characteristic distance measuring device. ADVANTAGE OF THE INVENTION According to this invention, the position to an object can be calculated | required accurately and easily from only the image information based on two imaging means.

According to a seventh aspect of the present invention, in the distance measuring device according to the sixth aspect, the distance calculation includes a staple unit having an output value corresponding to an input value in advance. It is. According to the present invention, an output value is immediately obtained for an input value, so that the operation speed can be increased quickly, and it is not necessary to use a high-speed operation means.

The present invention described in claim 8 is the distance measuring method described in claim 7, further comprising an aberration correcting unit that corrects an inherent aberration of the optical element of the imaging unit. . According to the present invention, a proper position can be measured by knowing in advance the inherent aberrations of a lens or the like and correcting them.

The present invention described in claim 9 is the distance measuring device according to claim 5, wherein the aberration correcting means is a table means provided in advance with an output value corresponding to the position of the input optical element. It is characterized by having. According to the present invention, arithmetic processing is required. The correction value for the input value is output immediately without any need.

According to a tenth aspect of the present invention, in the distance measuring device according to any one of the sixth to ninth aspects, the arithmetic unit and the aberration correction unit of the optical element are provided in the same table. It is characterized in that it is a flexible means. ADVANTAGE OF THE INVENTION According to this invention, calculation of the distance with respect to one value and correction | amendment of the aberration of an optical element can be performed by one table, and each calculation correction | amendment can be performed quickly, and calculation and correction Can minimize the number of devices required.

Claims

The scope of the claims

1. Each object is equipped with an image sensor, and an object is photographed by two image pickup means whose optical axes are crossed at a predetermined cross point (compare point: C P).

The coordinates of the same object photographed by the imaging devices of the two imaging units are obtained on the imaging device,

A distance measuring method comprising calculating a distance from an imaging position to an object from information acquired by the coordinate acquiring means.

2. The method for measuring a distance according to claim 1, wherein the calculation of the distance is performed using table means provided in advance with an output value corresponding to an input value.

3. The distance measuring method according to claim 1, wherein an inherent aberration of an optical element of the imaging means is captured.

4. The distance measuring method according to claim 1, wherein the correction of the aberration of the optical element is performed using a table means provided in advance with an output value corresponding to the position of the input optical element.

5. The distance measuring method according to any one of claims 1 to 4, wherein the calculation of the distance and the correction of the aberration of the optical element are performed using the same table.

6. Two imaging means, each equipped with an image sensor, with the optical axis crossing at a predetermined cross point (compare point: CP);

Coordinate acquisition means for obtaining coordinates on the image sensor of the same object photographed by both image sensors of the two image means;

Calculating means for calculating the distance from the imaging position to the object from the information obtained by the coordinate obtaining means.

7. The distance measuring method according to claim 5, wherein the distance calculation includes a table unit having an output value corresponding to an input value in advance.

8. The distance measuring method according to claim 7, further comprising an aberration correcting unit that corrects an inherent aberration of the optical element of the imaging unit.

9. The distance measuring method according to claim 5, wherein the aberration correction unit is a table unit that is provided with an output value with respect to a position of an optical element to be input.

10. The distance measuring device according to any one of claims 6 to 9, wherein the distance calculating means and the aberration correcting means of the optical element are the same table means. '