JP2002081908A - Method for acquiring information, image pickup device, and image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information acquiring means, etc., which can acquire the distance information, etc., to an object with higher accuracy by eliminating an error factor caused by the inclination, etc., of the surface of the object. SOLUTION: Two images of the object are picked up from the reflected light rays of light rays respectively projected upon the object from two optically different emitting positions at a position which is optically same to either one of the two emitting positions. The distance information, etc., to the object can be acquired with higher accuracy by eliminating the error factor caused by the inclination, etc., of the surface of the object by calculating the distance information to the portion to be measured of the object based on reflected light rays from the portion to be measured and its vicinity. In addition, when the wavelengths of the light rays projected upon the object from the two emitting positions are made different from each other, the images of the object can be picked up simultaneously with the emission of the light rays, and the distance information, etc., can be acquired with higher accuracy even when the object moves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information acquisition method, an image pickup device, and an image processing device for acquiring information on the depth distance of an object, the inclination of the object surface, and the reflectance of the object surface. More particularly, the present invention relates to an information acquisition method, an image capturing apparatus, and an image processing apparatus for capturing reflected light obtained from an object irradiated with light and acquiring information on the object.

[0002]

2. Description of the Related Art In order to obtain distance information to an object and position information of the object, a three-dimensional image in which a pattern light such as a slit or a striped pattern is projected on the object, and the pattern projected on the object is photographed and analyzed. Measurement techniques are known. Typical measurement methods include the slit light projection method (also called the light shredding method),
There are coded pattern light projection methods and others, and he is familiar with "3D image measurement" by Shoji Iguchi and Kosuke Sato (Shokodo).

[0003] JP-A-61-155909 (publication date: July 15, 1986) and JP-A-63-233312
Japanese Patent Application Laid-Open Publication No. (published on Sep. 29, 1988) discloses a distance measuring device that irradiates an object from different light source positions and measures a distance to the object based on an intensity ratio of reflected light from the object. A distance measuring method is disclosed.

Japanese Patent Laid-Open Publication No. Sho 62-46207 (published on Feb. 28, 1987) discloses that an object is irradiated with two lights having different phases, and based on the phase difference of the reflected light from the object. A distance detecting device for measuring a distance to a vehicle is disclosed.

[0005] Also, Kahoku et al., "AXi-Vision 3D Imaging Device"
Camera Development ”(3D Image Conference 99, 19
In 1999), ultra-high-speed intensity modulation was applied to the projection light, and an object illuminated with the intensity-modulated light was photographed with a camera equipped with a high-speed shutter function. Is disclosed.

Japanese Patent Application Laid-Open Nos. 10-48336 and 11-94520 disclose that different light patterns having different wavelength characteristics are projected on an object to extract a wavelength component of incident light from the object. A real-time range finder for calculating a distance to an object is disclosed.

[0007]

In the conventional distance measuring device and the conventional distance measuring method, the distance information is measured by irradiating the object with light and measuring the reflected light. Did not consider the inclination of the surface. Therefore, even if the objects are at the same distance, the measurement intensity of the reflected light varies depending on the inclination of the surface, and an error occurs in the distance measurement.

In the distance detecting device disclosed in Japanese Patent Application Laid-Open No. 62-46207, a highly accurate phase detector for detecting a phase difference is required, and the device becomes expensive.
Lack of convenience. Further, since the phase of light emitted from a point of the subject is measured, the depth distribution of the entire subject cannot be measured.

Also, Kahoku et al., "Axi-Vision three-dimensional imaging device"
Camera Development ”(3D Image Conference 99, 19
1999), the distance measurement method using intensity modulation,
Since the same light source is used to increase and decrease the intensity, light modulation must be performed at a very high speed, and measurement cannot be performed easily.

[0010]

According to a first aspect of the present invention, there is provided an information acquiring method for acquiring distance information to an object, the method comprising:
An irradiation step of irradiating an object with light from a point irradiation position;
An imaging step of imaging reflected light from an object due to light emitted from a point irradiation position, and an angle calculation for calculating one of angles at which light is emitted to the object from two optically different irradiation positions. And a calculating step of calculating distance information to the measured portion based on the reflected light of the measured portion of the object and the reflected light from the vicinity of the measured portion captured at the imaging position. An information acquisition method is provided.

In the imaging step, at an imaging position that is optically the same as one of the two irradiation positions, the reflected light from the object by the light emitted from the two irradiation positions is imaged, and the angle measurement step is performed. May calculate the angle at which the light is emitted based on the reflected light from the object to be imaged in the imaging step.
The calculating step is based on the intensity of the reflected light from the measured portion and the intensity of the reflected light from the vicinity of the measured portion, which are imaged in the imaging stage, and based on the distance information of the measured portion and the surface of the measured portion. The inclination information may be calculated. In the calculating step, based on the intensity of the reflected light from the measured part and the incident angle of the reflected light, assuming temporary distance information to the measured part, the surface inclination information of the measured part is calculated. A first calculating step of:
A second calculating step of calculating temporary distance information near the measured portion based on the temporary distance information to the measured portion and the surface inclination information of the measured portion; and a temporary distance near the measured portion. Information and
A third calculating step of calculating surface tilt information near the measured portion based on the intensity of reflected light from the vicinity of the measured portion and the incident angle of the reflected light; A fourth calculating step of calculating an error with the surface inclination information near the measuring unit, and when the error is within a predetermined range, the temporary distance information of the measured unit is converted to the true distance information of the measured unit. It may be output as distance information.

In a fourth calculating step, an error is calculated for each of a plurality of provisional distance information of the measured part.
The provisional distance information of the measured part when the error is minimized may be used as the true distance information of the measured part. In the second calculation step, temporary distance information near the measured portion may be calculated in the vicinity where the surface of the measured portion is extended, based on the surface inclination information of the measured portion. In the imaging step, reflected light from the measured section and
The reflected light from a plurality of places near the measured part is imaged, and the fourth calculating step includes, at a plurality of places near the measured part,
An error between the temporary surface inclination information of the measured part and the temporary surface inclination information in the vicinity of the measured part is calculated, respectively, and the calculating step is a step of calculating the temporary surface inclination of the measured part when the sum of squares of the error is minimized. The distance information may be true distance information of the measured part.

The irradiating step includes irradiating the object to be measured and the vicinity of the object to be measured of the object at each irradiation position, and irradiating the light to the object substantially simultaneously at each irradiation position. The imaging step may include wavelength selection means for selectively transmitting each of light of different wavelengths, and each of the light reflected at each irradiation position from the object may be imaged.

According to a second aspect of the present invention, there is provided an image pickup apparatus for acquiring distance information to an object, comprising: an irradiating section for irradiating the object with light from two optically different irradiation positions; An imaging unit which optically reflects at one of the irradiation positions of the points, and which captures reflected light of the light from the object by light emitted from the two irradiation positions, and a measured object measured by the imaging unit; An image processing apparatus comprising: an image processing device that calculates distance information to a measured portion based on reflected light from the portion and reflected light from the vicinity of the measured portion.

At each irradiation position, a control unit may be further provided for synchronizing a light emission timing at which the irradiation unit emits light and an imaging timing at which the imaging unit captures reflected light. The irradiation unit irradiates light of different wavelengths at each irradiation position, irradiates the object with light at substantially the same time at each irradiation position, and reflects the light of the different wavelength light reflected by the object at each of the different wavelengths. The image processing apparatus may further include a light splitting unit that splits the light into light having a main wavelength component, and the imaging unit may image each of the separated light. The spectroscopy unit may include a plurality of optical filters that mainly transmit each of light of different wavelengths.

According to a third aspect of the present invention, there is provided an image processing apparatus for processing an image obtained by capturing an image of an object, the image processing apparatus comprising: An input unit for inputting data, a storage unit for storing the input image data, and distance information to the measured unit and measured data based on the measured data of the object of the image data and data near the measured unit. An image processing apparatus comprising: a calculating unit that calculates surface inclination information of a unit; and an output unit that outputs distance information and surface inclination information calculated by the calculating unit.

The image data is data obtained by imaging means having a plurality of pixels that receive the reflected light, and the calculation unit calculates the intensity of the reflected light of each light emitted from two irradiation positions for each pixel. May be extracted, and the distribution of the distance information and the distribution of the plane inclination information of the object may be calculated based on the intensity of each pixel of the reflected light from the measured part and the vicinity of the measured part of each extracted light. The calculation unit may calculate the three-dimensional information of the object based on the distribution of the distance information and the distribution of the plane inclination information, and the output unit may output the three-dimensional information of the object calculated by the calculation unit.

The calculating section calculates the surface inclination information of the measured section based on the assumption of the temporary distance information to the measured section based on the intensity of the reflected light from the measured section and the incident angle of the reflected light. First calculating means, and temporary distance information to the measured part;
Second calculating means for calculating temporary distance information near the measured part based on the surface inclination information of the measured part; temporary distance information near the measured part; and reflection from the measured part. Third calculating means for calculating surface tilt information near the measured portion based on the light intensity and the incident angle of the reflected light; surface tilt information of the measured portion; and surface tilt information near the measured portion. And fourth calculating means for calculating an error from the measured value, and when the error is within a predetermined range, provisional distance information of the measured part may be output as true distance information of the measured part. .

The fourth calculating means calculates an error for each of the plurality of temporary distance information of the measured section, and the calculating section calculates the temporary distance information of the measured section when the error is minimized. May be the distance information of the part to be measured. The second calculating means may calculate, based on the surface inclination information of the measured portion, temporary distance information near the measured portion in the vicinity where the surface of the measured portion is extended. The input section receives image data based on the reflected light from the measured section and the reflected light from a plurality of places near the measured section, and the fourth calculating means calculates a plurality of places and a plurality of places near the measured section. Then, an error between the temporary surface inclination information of the measured portion and the temporary surface inclination information near the measured portion is calculated, and the calculating portion calculates the temporary surface inclination information when the sum of squares of the error is minimized. May be used as the true distance information of the measured part.

[0020] The calculation unit is configured to calculate, based on the image data of the object,
The calculating unit detects the edge of the object, and among the plurality of locations near the measured unit, there is data of the measured unit in a region obtained by dividing the image data of the object into a plurality of regions with the edge of the object as a boundary. The distance information of the measured portion may be calculated based on temporary surface tilt information at a location near the measured portion, which has data in the same region as the region. Further, the calculation unit, among a plurality of locations near the measured portion, the difference between the intensity of the reflected light from the measured portion and the intensity of the reflected light from the vicinity of the measured portion is within a predetermined range, The distance information of the measured part may be calculated based on temporary surface inclination information of a place near the measured part.

The above summary of the present invention does not list all of the necessary features of the present invention, and a sub-combination of these features can also be an invention.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the invention according to the claims, and are described in the embodiments. Not all combinations of features are essential to the solution of the invention.

FIG. 1 is a diagram illustrating the principle of the present invention. From the irradiation position 12 and the irradiation position 14, the intensity P1, P
The object 20 is irradiated with two lights, and the reflected light of each light by the object 20 is imaged by the camera 10. The camera 10 is, for example, a charge-coupled device (CCD), has a plurality of pixels, and captures reflected light from the measured portion 22 of the object 20 and the vicinity 24 of the arsenic domain portion for each pixel. Each intensity is detected every time. Based on the reflected light imaged by the camera 10, the distance L to the measured part 22 of the object 20 and the measured part 2
Inclination theta ₀ and 2 of the surface, to calculate the reflectivity _{R Obj} of the surface of the measuring unit 22. The irradiation positions (12, 14) may be arranged at any positions. One of the irradiation angles of the light radiated to the object 20 from the irradiation positions (12, 14) is calculated. In this example, the camera 10 is optically connected to one of the irradiation positions (12, 14). It is arranged at the same position, and calculates the irradiation angle of the light applied to the object 20 based on the incident angle of the reflected light captured by the camera 10. In this example, a case where the irradiation position 12 and the camera 10 are arranged at the same optical position will be described.

As shown in FIG. 1, the irradiation position 14 is located at a position L ₁₂ away from the irradiation position 12. Distance L
Reference numeral ₁₂ is a known value unique to the measurement system. Further, angles at which light is irradiated from the irradiation positions (12, 14) to the measured portion 22 of the object 20 are denoted by θ ₁ and θ ₂ , respectively, and the irradiation positions (12, 14)
Angles at which light is irradiated from the area 14) to the vicinity 24 of the measured portion of the object 20 are denoted by θ ₁ ′ and θ ₂ ′, respectively. Further, since the camera 10 is disposed at the same optical position as the irradiation position 12, the angle at which the reflected light from the measured part 22 is received is θ _C , and the reflected light from the vicinity 24 of the measured part is received. Assuming that the angle is θ _C ′, θ _C = θ ₁ and θ _C ′ = θ ₁ ′. Further, the distance from the irradiation position 12 to the measured portion 22 is L ₁ , and the distance from the measured portion to the vicinity 24 is L ₁ ′.
The distance from the irradiation position 14 to the measured portion is L ₂ , and the distance from the measured portion to the vicinity 24 is L ₂ ′.

The intensities of the light emitted from the irradiation positions (12, 14) and the reflected light from the measured portion 22 are D ₁ and D ₁ , respectively.
Assuming that D ₂ , D ₁ and D ₂ are given as follows.

(Equation 1) That is,

(Equation 2) Becomes

Also,

(Equation 3) So that

(Equation 4) Becomes Also,

(Equation 5) Since L ₁₂ and θ ₁ are known values, θ ₂ is L
Given by That is,

(Equation 6) Becomes Therefore,

(Equation 7) Becomes _{Here, D1, D 2, P 1} , P 2, θ 1 , so is the measurement value or known values, unknowns above formula are two of theta ₀ and L. Therefore, a combination of (θ ₀ , L) satisfying the above condition can be obtained. That is, when the distance L to the measured portion 22 is assumed, the surface inclination θ ₀ of the measured portion corresponding to the assumed distance L can be calculated. Also, for the vicinity 24 of the measured part,
Similarly, a combination of the distance L ′ to the neighborhood 24 of the measured part and the surface inclination θ ₀ ′ of the neighborhood 24 of the measured part can be obtained.

According to the present invention, a combination of the distance L of the object 20 to the measured portion 22 and the surface inclination θ ₀ of the measured portion 22 is represented by:
Based on a combination of the distance L ′ to the vicinity 24 of the measured portion of the object 20 and the surface inclination θ ₀ ′ of the vicinity 24 of the measured portion, the distance L to the measured portion 22 and the surface inclination θ ₀ are calculated. . Hereinafter, the calculation method will be described in detail.

FIG. 2 shows the distance L to the measured portion 22 and the measured
Surface inclination θ of the fixed part 22₀In the explanatory diagram of an example of a method for calculating
is there. First, it is assumed that the distance L to the measured part 22 is La.
You. Based on the equations described in connection with FIG.
Surface inclination θ of measured part 22 corresponding to distance La₀Calculate
You. Next, the calculated surface inclination θ₀Measured part determined by
22 is extended to reflect the reflected light from the vicinity 24 of the measured part.
It is assumed that there is a neighborhood 24 of the measured part at a point where the optical path intersects.
The temporary distance Lb to the neighborhood 24 of the measured part when
calculate. At this time, the temporary distance to the neighborhood 24 of the measured part
Lb is a temporary distance L between the camera 10 and the measured part 22.
a, the incident angle θ of the reflected light from the measured section 22 ₁, Measured part
Incident angle θ of the reflected light from the neighborhood 24₁’And the part to be measured
22 plane inclination θ₀Can be calculated geometrically based on
Wear.

Next, corresponding to the calculated temporary distance Lb,
The surface inclination θ ₀ ′ in the vicinity 24 of the measured part is calculated. The plane inclination θ ₀ ′ can be calculated by the mathematical expression described with reference to FIG. Since the distance between the measured portion 22 of the object 20 and the vicinity 24 of the measured portion is minute, the surface inclination of the measured portion 22 and the vicinity 24 of the measured portion are substantially the same. Therefore, by comparing the calculated plane inclination θ ₀ and θ ₀ ′, it can be determined whether the initially assumed distance La to the measured portion 22 is a correct value. That is, if the difference between the plane inclinations θ ₀ and θ ₀ ′ is within a predetermined range, the assumed distance La can be set as the distance L to the measured section 22.

If the difference between the plane inclinations θ ₀ and θ ₀ ′ is not within the predetermined range, it is determined that the initially assumed distance La is incorrect, and the distance L to the measured portion 22 is changed. Similar calculations may be performed by setting other values. The distance L to the measured part 22 that satisfies the mathematical expression described with reference to FIG.
Obviously, it has an upper limit value and the lower limit value is zero, so the provisional distance La may be checked in a finite range. For example, the true distance L to the measured portion 22 may be extracted by a binary search method for the distance La in a finite range. Further, for the temporary distance La, the difference between θ ₀ and θ ₀ ′ may be calculated at predetermined distance intervals within a finite range, and the true distance L may be extracted. In addition, for the temporary distance La, a difference between θ ₀ and θ ₀ ′ may be calculated for a plurality of values, and the temporary distance La with the minimum difference may be set as the true distance L. Further, the surface inclination information of the measured portion can be calculated based on the information on the distance to the measured portion by the mathematical formula described with reference to FIG. In addition, the surface reflectance information of the measured portion can be calculated by the mathematical formula described with reference to FIG.

FIG. 3 shows an example of the result of calculating the surface tilt θ ₀ and the surface tilt θ ₀ ′ at predetermined distance intervals within a predetermined range of the temporary distance La. In the graph of FIG. 3, the horizontal axis represents the temporary distance La to the measured section 22, and the vertical axis represents the surface inclination of the measured section 22 and the vicinity 24 of the measured section.
In this example, the distance L of the object 20 to the measured portion 22 was 200 mm, and the surface inclination of the measured portion 22 was 0 degree. Further, the distance between the irradiation position 12 and the irradiation position 14 is 10 mm,
theta ₁ 20 degrees, was calculated the distance of the temporary distance La as 10 mm.

Data 102 indicates the surface inclination of the measured part 22 corresponding to the provisional distance La shown on the horizontal axis.
Numeral 04 indicates the surface inclination of the vicinity 24 of the measured part. At a tentative distance of 200 mm, the surface inclinations of the measured portion 22 and the vicinity 24 of the measured portion match at 0 degree.

FIG. 4 shows an image pickup apparatus 100 according to the present invention.
An example of the configuration will be shown. The image capturing apparatus 100 includes the irradiation unit 4
0, a spectral unit 50, a control unit 60, an imaging unit 70, and an image processing device 300. The irradiation unit 40 irradiates the object 20 with light from two optically different irradiation positions. The irradiation unit 40 has a light source at each of two irradiation positions, and may irradiate the object 20 with light from each light source. The irradiation unit 40 has one light source and one light source. The object 20 may be irradiated with light by moving to each of the irradiation positions (12, 14). When the irradiation unit 40 has a light source at each of the two irradiation positions, the object 20 may be irradiated with light of a different wavelength substantially simultaneously at each of the irradiation positions. The spectroscopy unit 50 separates reflected light from the object 20 due to light of different wavelengths into light having different wavelengths as main wavelength components. The imaging unit 70 captures the reflected light of the object 20 due to the light emitted from the two irradiation positions at the same optical position as any one of the two irradiation positions. The imaging unit 70 may capture each of the lights separated by the spectroscopy unit 50. The control unit 60 synchronizes the emission timing at which the irradiation unit 40 emits light and the imaging timing at which the imaging unit 70 captures reflected light at each irradiation position.

The image processing apparatus 300 obtains distance information to the measured section 22 based on the reflected light from the measured section 22 and the reflected light from the vicinity 24 of the measured section of the object 20 imaged by the imaging section 70. Is calculated. Image processing device 300
Includes an input unit 80, a storage unit 90, a calculation unit 110, and an output unit 120. The input unit 80 inputs image data based on the respective reflected lights by the object 20 of the respective lights emitted from the two irradiation positions. The storage unit 90
The image data input to the input unit 80 is stored. The storage unit 90 may store image data for each wavelength characteristic of light emitted by the irradiation unit 40.

The calculating section 110 calculates distance information of the object 20 to the measured section 22 and information of surface inclination of the measured section 22 of the object 20 based on the image data stored in the storage section 90. The calculating unit 110 calculates the surface inclination information of the measured unit 22 when assuming temporary distance information to the measured unit based on the intensity of the reflected light from the measured unit 22 and the incident angle of the reflected light. A second calculating step of calculating temporary distance information in the vicinity 24 of the measured part based on temporary distance information to the measured part 22 and surface inclination information of the measured part 22; Based on the temporary distance information of the neighborhood 24 of the measured part, the intensity of the reflected light from the neighborhood 24 of the measured part, and the incident angle of the reflected light, the surface inclination information of the neighborhood 24 of the measured part is calculated. There is provided a third calculating means, and a fourth calculating means for calculating an error between the surface inclination information of the measured part and the surface inclination information in the vicinity 24 of the measured part. When the error calculated by the fourth calculating unit is within a predetermined range, the calculating unit 110
Is output to the output unit 120 and the storage unit 90 as the true distance information of the measured unit 22.

The fourth calculating means calculates an error for each of the plurality of provisional distance information of the measured section 22, and calculates the error.
10 may use the temporary distance information of the measured section 22 when the error is minimized as the true distance information of the measured section 22. Further, the second calculating means may calculate a temporary distance of the vicinity 24 of the measured portion in the vicinity where the surface of the measured portion 22 is extended, based on the surface inclination information of the measured portion 22.

The calculating section 110 detects the intensity of the reflected light on a pixel basis or on a pixel area basis of the image pickup section 70 based on the image data, and calculates the distance to the object 20 based on the detected intensity of the reflected light. Information distribution and plane inclination information may be calculated. The calculation unit 110 may calculate the three-dimensional information of the object 20 based on the distribution of the distance information and the distribution of the plane inclination information. The calculation unit 110 may calculate the distribution of each piece of information of the measurement target unit 22 and each piece of information of the object 20 by the same or the same method as described with reference to FIGS. 1 to 3. When the irradiating unit 40 irradiates light of different wavelengths, the calculating unit 110 uses the method described with reference to FIG. 6 to irradiate the light of the same wavelength from each irradiating position. It is preferable to calculate the intensity and calculate the distribution of each information of the measured section 22 and each information of the object 20 based on the calculated intensity. It is preferable that the storage unit 90 stores the distribution of each piece of information of the measured section 22 calculated by the calculation unit 110 and each piece of information of the object 20.

The output section 120 outputs information on the distance of the object 20 to the measured section 22, information on the surface inclination of the measured section 22, and the distribution of each piece of information on the object 20, calculated by the calculating section 110. The output unit 120 may display the distribution of each piece of information of the measured section 22 and each piece of information of the object 20 on a display device using numerical values and graphics. Further, the output unit 120 may output the distribution of each piece of information of the measured section 22 and each piece of information of the object 20 by sound. The output unit 120 may output each information based on the position information specified in advance. Further, the output unit 120 may output based on items and criteria specified in advance. For example, each piece of information may be output for an area where a predetermined item is equal to or more than a certain value. Also,
The output unit 120 may output each information based on whether the object 20 is stationary or moving.

The input section 80 receives image data based on the reflected light from the measured section 22 and the reflected lights from a plurality of places near the measured section, and the fourth calculating means of the calculating section 110 At a plurality of locations near the measured part, errors are calculated between the tentative plane inclination information of the measured part 22 and the tentative plane inclination information near the measured part, and the calculating unit 110 calculates the sum of squares of the error. May be used as the true distance information of the measured part 22 when the surface inclination information of the measured part 22 is minimum.

In this embodiment, the image pickup device 100
Is provided with a spectroscopic unit 50, but when the irradiation unit 40 irradiates light at different irradiation positions at different timings,
The image capturing apparatus 100 does not include the spectral unit 50, and
May image the reflected light of the light emitted from each irradiation position at a timing based on the timing at which the irradiation unit 40 irradiates the light.

FIG. 5 shows an example of image data 150 based on the reflected light from the object 20 captured by the image capturing section 70. The object 20 has an edge 1 where the surface inclination changes rapidly at a small distance.
56. The calculating unit 110 detects the edge of the object based on the image data 150 based on the reflected light from the object 20, and detects the image of the object 20 using the edge of the object 20 as a boundary among a plurality of locations near the measured part. Based on temporary surface tilt information at a location 24 near the part to be measured, where the data is located in the same area as the area where the data of the part to be measured 22 is located, the data is divided into a plurality of areas. Is calculated. For example, as shown in FIG. 5, when the image data 150 of the object 20 is in the region 1 with the edge 156 as the boundary.
52 and the region 154, the calculation unit 110 is located in the region 152 where the data of the measured unit 22 exists.
Based on the surface inclination information of the neighborhood 24 of the measured part, the measured part 2
2 is calculated.

The calculating unit 110 determines that the difference between the intensity of the reflected light from the measured part 22 and the intensity of the reflected light from the vicinity of the measured part among a plurality of locations near the measured part is a predetermined value. The distance information of the measured section 22 may be calculated based on temporary surface tilt information at a location near the measured section within the range.

FIG. 6 illustrates an example of the image pickup apparatus 100.
FIG. In FIG. 6, the same reference numerals as in FIG.
Is the same or similar function as described in connection with FIG.
And a configuration. The irradiation unit 40 is optically different
From the two irradiation positions (12, 14) to the object 20
Irradiate the object 20 with light of different wavelengths substantially simultaneously.
You. For example, the irradiation unit 40 emits light having different wavelengths.
It has an optical filter (not shown) that mainly transmits
Is also good. At this time, the irradiating unit 40 is set at each irradiation position.
Light emitted from (12, 14) is passed through an optical filter.
And the wavelength λ_a, Λ _bSubstantially the same as the object 20
Sometimes irradiated.

The light emitted from the irradiation unit 40 is
And is incident on the optical lens 52. Optical lens 52
The reflected light from the object 20 that has entered into the light splitter 50 is incident on the light splitting unit 50 via the optical lens 52.

The spectroscopy unit 50 includes an optical lens 52 as an example.
Has a deflector for deflecting the reflected light formed as an image, a retarder for rotating the deflecting direction of the deflected light according to the wavelength, and a prism for splitting light having different deflecting directions. The light split by the splitting unit 50 is captured by the imaging unit (70a, 70b).
Is received. The imaging units (70a, 70b) are, for example, two solid-state imaging devices. Imaging unit (70a, 70
The light received in b) is read out as electric charges by the photoelectric effect, converted into a digital electric signal by an A / D converter (not shown), and input to the image processing device 300. The image processing device 300 determines the object 2 based on the input signal.
0, distance information of the surface of the object 20, object 2
The reflectance information of the zero surface is calculated.

The image pickup section 70 picks up each of the lights separated by the spectroscopic section 50. The imaging unit 70 is, for example, a solid-state imaging device, and an image of the object 20 is formed on a light receiving surface of the solid-state imaging device. Charges are accumulated in each sensor element of the solid-state imaging device according to the amount of light of the image of the formed object 20, and the accumulated charges are scanned in a certain order.
Read as an electrical signal. The solid-state imaging device is the object 2
It is preferable to use a charge-coupled device (CCD) image sensor having a good signal / noise ratio and a large number of pixels so that the intensity of the reflected light from 0 can be detected with high accuracy in pixel units. In addition to the CCD, a MOS image sensor, a Cd-Se contact image sensor, an aSi contact image sensor, a bipolar contact image sensor, or the like may be used as the solid-state imaging device.

The control unit 60 controls the emission timing at which the irradiation unit 40 emits light and the imaging timing at which the imaging unit 70 captures reflected light. The control unit 40 receives the synchronization signal, and controls the light emission timing and the imaging timing based on the synchronization signal. Further, the control unit 60 may control the intensity of the light emitted from the irradiation unit 40, the focus of the imaging unit 70, the aperture, and the like based on the distance information to the object 20. The control unit 60 may control the exposure time of the imaging unit 70.

In this embodiment, the irradiation unit 40 irradiates light having one wavelength as a main wavelength component at each of two irradiation positions. In other examples, the irradiation unit 40 has two irradiation positions.
At each of the irradiation positions of the points, light having a plurality of wavelengths as main wavelength components may be irradiated. At this time, the spectroscopy unit 50
It is preferable that the reflected light from the object 20 be divided into a plurality of wavelength components of a plurality of wavelengths of the light irradiated by the irradiation unit 40. However, when splitting into all wavelength components,
0 may be too large. Therefore, in yet another example, the irradiation unit 40, in the irradiation position 12 is irradiated with light for a wavelength lambda _a and the main wavelength component, the irradiation position 1
In 4, the two wavelengths and a main wavelength component, the average value of the two wavelengths may be irradiated with light such that the wavelength lambda _a. At this time, the spectroscopy unit 50 divides the reflected light from the object 20 into wavelength components of the light emitted from the respective irradiation positions. That is, the light splitting unit 50 splits the reflected light into two types of light. The image processing apparatus 300 determines the object 20 based on the reflected light intensity of the light irradiated from the irradiation position 12 and the half of the reflected light intensity of the light irradiated from the irradiation position 14.
Is calculated.

In this embodiment, the spectroscopic section 50 has a prism. However, in another embodiment, the spectroscopic section 50 may have a plurality of optical filters that mainly transmit light of different wavelengths. The optical filter is arranged on the light receiving surface of the imaging unit 70. When the irradiation unit 40 does not simultaneously irradiate light at each irradiation position, the imaging unit 70 may image the reflected light without passing through the spectroscopy unit 50.

FIG. 7 shows an example of the wavelength of light irradiated from the irradiation positions (12, 14). In this example, light having a main wavelength component of λa is irradiated from the irradiation position 12, and light having two main wavelength components λb and λc is irradiated from the irradiation position 12. Further, the intensity of the reflected light from the object 20 due to the light irradiated from the irradiation position 12 is W, and the intensity of the reflected light from the object 20 due to the light having the wavelength λb as a component of the light irradiated from the irradiation position 14. Is Wb, and the intensity of light reflected from the object 20 by light having a wavelength λc as a component is Wc. In this case, the spectroscopy unit 50 splits the reflected light from the object 20 into light having a wavelength λa as a main wavelength component and light having wavelengths λa and λb as main wavelength components.
The spectroscopic unit 50 is configured to use, for example, an optical filter to
May be split.

As shown in FIG. 7A, when light is irradiated from the irradiation position 14 so that the average value of the wavelengths λb and λc is λa, the intensity Wb of the reflected light due to the light having the wavelength λb as a component is obtained. And the average value Wa of the reflected light intensity Wc due to the light having the wavelength λc as a component, thereby calculating the object 20 when the light of the wavelength λa is irradiated from the irradiation position 14.
Can be calculated. That is,
Regarding the reflected light intensity taking into account the attenuation of an optical filter or the like for dividing the reflected light, 強度 of the intensity of the reflected light due to light having wavelengths λb and λc irradiated from the irradiation position 14 as main wavelength components is used. Is calculated, the irradiation position 14
The intensity of the reflected light from the object 20 when the light of the wavelength λa is radiated can be calculated.

As shown in FIG. 7B, the wavelength λb
The intensity of the reflected light from the object 20 when the light of the wavelength λa is irradiated from the irradiation position 14 may be calculated by linearly approximating the intensity of the reflected light by the light having the component having the wavelength λc. As described in this example, the object 20 is irradiated with light of a different wavelength at each irradiation position,
The reflected light from the object 20 is wavelength-separated by the spectroscopic unit 50,
By imaging, each of the reflected lights by the light emitted from the two irradiation positions can be simultaneously imaged, so that even when the object 20 is moving, the object 2
It is possible to calculate distance information up to 0 and plane inclination information. In FIG. 7, light having two wavelength components as main wavelength components is irradiated from the irradiation position 14, but in another example, light having more wavelengths as main wavelength components is applied to the object 20. Irradiation may be performed.

FIG. 8 shows an example of the image processing apparatus 300. The image processing device 300 may have the same or similar function and configuration as the image processing device 300 described with reference to FIG. In this example, the input unit 80, the recording unit 90, and the output unit 120 have the same or similar functions and configurations as those described with reference to FIG.

The calculation unit 110 includes the CPU 82 and the input device 8
8, ROM 84, hard disk 92, RAM 86, C
It has a D-ROM drive 94. The CPU 82 outputs the RO
It operates based on the programs stored in M84 and RAM86. Data is input by the user through an input device 88 such as a keyboard and a mouse. The hard disk 92 stores data such as images and a program for operating the CPU 82. The CD-ROM drive 94 is C
Read data or program from D-ROM 96,
It is provided to at least one of the RAM 86, the hard disk 92, and the CPU 82.

The functional configuration of the program executed by the CPU 82 is the same as the functional configuration of the calculation unit 110 of the image processing apparatus 300 described with reference to FIG. 4, and irradiates the object 20 with light from two irradiation positions. In the case, an input module for inputting the intensity of reflected light from the object 20 due to light from each irradiation position, and a calculation module for calculating distance information to the object 20 based on each intensity of the reflected light. Having. The processing that the input module and the calculation module cause the CPU 82 to perform is the same as the function and operation of the calculation unit 110 described with reference to FIG. These programs are CD-R
It is provided to the user stored in a recording medium such as OM84. The CD-ROM 96 as an example of the recording medium can store some or all of the functions of the operation of the image processing device 300 described in the present application.

The above program is directly executed from a recording medium.
It may be read by the AM 86 and executed by the CPU 82. Alternatively, the above-mentioned program can use a magnetic recording medium such as a hard disk (MD), a magneto-optical recording medium such as an MO, a tape-shaped recording medium, a nonvolatile semiconductor memory card, or the like from the recording medium.

The above program may be stored on a single recording medium, or may be divided and stored on a plurality of recording media. Further, the program may be compressed and stored in a recording medium. The compressed program may be expanded, read to another recording medium such as the RAM 86, and executed. Further, the compressed program is a CP
After being expanded by the U82 and installed on the hard disk 92 or the like, it may be read out to another recording medium such as the RAM 86 and executed.

Further, a CD-R as an example of a recording medium
The OM 96 may store the program provided by the host computer via the communication network. The above program stored in the recording medium may be stored in the hard disk of the host computer, transmitted from the host computer to the computer via a communication network, read out to another recording medium such as the RAM 86, and executed. .

The recording medium storing the above program is
It is only used to manufacture the image processing apparatus 300 of the present application, and it is clear that manufacture and sale of such a recording medium as a line constitutes infringement of the patent insurance based on the present application. .

FIG. 9 shows an example of a flowchart of the information acquisition method according to the present invention. In the information acquisition method according to the present invention, an irradiation step of irradiating an object with light from two optically different irradiation positions and an image of reflected light from the object by light irradiated from the two irradiation positions are respectively taken. An imaging stage;
An angle calculating step of calculating any one of angles at which the object is irradiated with light from two optically different irradiation positions; reflected light of the measured portion of the object, which is imaged at the imaging position; Calculating the distance information to the measured portion based on the reflected light from the vicinity of the target. In the present example, in the imaging step, at an imaging position that is optically the same as one of the two irradiation positions, the reflected light from the object by the light emitted from the two irradiation positions is imaged, and the angle is calculated. In the measuring step, an angle at which light is emitted is calculated based on reflected light from an object to be imaged in the imaging step.

In the calculating step, based on the intensity of the reflected light from the part to be measured and the intensity of the reflected light from the vicinity of the part to be measured, the distance information of the part to be measured and the intensity of the part to be measured are taken. Surface inclination information may be calculated. Hereinafter, a method of calculating the distance information to the measured portion in the calculation stage using the flowchart will be described.

In the calculation step, first, in the first calculation step,
Based on the intensity of the reflected light from the measured part and the incident angle of the reflected light, temporary distance information to the measured part is assumed (S10).
0). Next, based on the assumed distance information, surface inclination information of the measured part is calculated (S102). The method of calculating the surface inclination information of the measured part based on the assumed distance information is as follows.
The calculation may be the same or similar to the method described with reference to FIGS. 1 to 3.

Next, in the second calculation step, temporary distance information near the measured portion is calculated based on the temporary distance information to the measured portion and the surface inclination information of the measured portion (S10).
4). The method of calculating the temporary distance information in the vicinity of the measured part may be calculated by the same or similar method as the method described with reference to FIGS.

Next, in the third calculation step, the vicinity of the measured part is determined based on the temporary distance information near the measured part, the intensity of the reflected light from the vicinity of the measured part, and the incident angle of the reflected light. Is calculated (S106). The method of calculating the surface tilt information near the measured portion may be calculated by the same or similar method as the method described with reference to FIGS.

Next, in the fourth calculation step, an error between the surface inclination information of the measured part and the surface inclination information near the measured part is calculated (S108). It is determined whether or not the calculated error is within a predetermined range (S110). If the calculated error is within the predetermined range, the temporary distance information of the measured part is replaced with the true distance information of the measured part. It is output as distance information (S112). If the calculated error is out of the predetermined range, the process returns to the first calculation step with the provisional distance information of the measured part as another value.
That is, for a plurality of temporary distance information of the measured part, S1
The calculation from 00 to S110 is performed.
For each of the plurality of temporary distance information of the measured part, an error is calculated, and in the calculation step, the temporary distance information of the measured part when the error is minimized is taken as the true distance information of the measured part. Is also good. Based on the calculated distance information, it is possible to calculate the surface inclination information of the measured section.

Similarly to the method described with reference to FIG. 2, the second calculation step is based on the surface inclination information of the measured part, in the vicinity where the surface of the measured part is extended, and in the vicinity of the measured part. Temporary distance information may be calculated. In the imaging step, reflected light from the measured section and reflected light from a plurality of locations near the measured section are imaged. In the fourth calculation step, the reflected light is measured at a plurality of locations near the measured section. An error between the temporary surface inclination information of the measuring unit and the temporary surface inclination information near the measured unit is calculated, and the calculating step includes provisional distance information of the measured unit when the sum of squares of the error is minimized. May be used as true distance information of the measured part. By performing the calculations described in the flowchart based on image data obtained from reflected light from a plurality of locations near the measured part, it is possible to obtain distance information to the measured part with reduced noise and calculation errors. it can.

The irradiating step includes irradiating the object to be measured and the vicinity of the object to be measured of the object at the respective irradiation positions, and irradiating the light to the object at the respective irradiation positions substantially simultaneously. The imaging step may include wavelength selection means for selectively transmitting each of light of different wavelengths, and each of the light reflected at each irradiation position from the object may be imaged.

In the information acquisition method described with reference to FIG. 8, the distance information to the measured part and the plane inclination information are calculated by the same or similar method as the method described with reference to FIGS. May do it.

Although the present invention has been described with reference to the embodiment, the technical scope of the present invention is not limited to the scope described in the above embodiment. It is apparent to those skilled in the art that various changes or improvements can be made to the above embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

[0070]

As is apparent from the above description, according to the present invention, by capturing an image of reflected light obtained from an object irradiated with light, an error due to the inclination of the surface of the object is eliminated, and Distance information can be obtained.
In addition, it is possible to acquire inclination information of the surface of the object 20 and reflectance information of the surface of the object 20.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram of an example of a method for calculating a distance L to a measured section 22 and a surface inclination θ ₀ of the measured section 22;

FIG. 3 shows an example of a result of calculating a plane inclination θ ₀ and a plane inclination θ ₀ ′ at predetermined distance intervals within a predetermined range of a temporary distance La.

FIG. 4 shows an example of a configuration of an image capturing apparatus 100 according to the present invention.

FIG. 5 illustrates an example of image data 150 based on reflected light from an object 20 captured by an imaging unit 70.

FIG. 6 is a diagram illustrating an example of the image capturing apparatus 100.

FIG. 7 shows an example of the wavelength of light emitted from the irradiation positions (12, 14).

FIG. 8 shows an example of an image processing apparatus 300.

FIG. 9 shows an example of a flowchart of an information acquisition method according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Camera, 12, 14 ... Irradiation position 20 ... Object, 22 ... Measured part 24 ... Near the measured part, 40 ... Irradiation part 50 ... Spectral part, Reference numeral 52: Optical lens 60: Control unit, 70: Imaging unit 80: Input unit, 82: CPU 84: ROM, 86: RAM 88: Input device, 92 ... Hard disk 94 ... CD-ROM drive, 96 ... CD-R
OM 90: storage unit, 100: image pickup device 110: calculation unit, 120: output unit 150: image data, 300: image processing device

Continued on the front page F-term (reference) 2F065 AA35 AA37 AA53 BB05 FF43 FF44 GG13 GG23 JJ03 JJ26 LL13 LL21 LL46 LL67 NN01 NN11 QQ03 QQ18 QQ23 QQ24 QQ25 QQ28 QQ42 2F112 AD05 BA06 CA12 FA02 FA03 FA03

Claims (21)

[Claims] 1. An information acquisition method for acquiring distance information to an object, comprising: irradiating the object with light from two optically different irradiation positions; and irradiating the object with light from the two irradiation positions. An imaging step of respectively imaging reflected light from the object by the light, and an angle calculation step of calculating any one of angles at which the object is irradiated with light from two optically different irradiation positions, A calculating step of calculating distance information to the measured portion based on reflected light from the measured portion of the object captured at the image capturing position and reflected light from the vicinity of the measured portion. An information acquisition method characterized in that: 2. The imaging step includes: at an imaging position that is optically the same as any one of the two irradiation positions, reflecting light reflected from the object by the light irradiated from the two irradiation positions. The method according to claim 1, wherein each of the images is captured, and the angle measuring step calculates an angle at which the light is emitted based on reflected light from the object captured by the imaging step. 3. The method according to claim 1, wherein the calculating step is performed based on an intensity of reflected light from the measured portion and an intensity of reflected light from the vicinity of the measured portion, which are imaged in the imaging step. 3. The information acquisition method according to claim 1, wherein the distance information and the surface inclination information of the measured portion are calculated. 4. The method according to claim 1, wherein the calculating step includes: assuming temporary distance information to the measured section based on an intensity of reflected light from the measured section and an incident angle of the reflected light. First to calculate the surface inclination information of the part
A second calculating step of calculating temporary distance information near the measured part based on the temporary distance information to the measured part and the surface inclination information of the measured part, Based on the provisional distance information in the vicinity of the measured portion, the intensity of reflected light from the vicinity of the measured portion, and the incident angle of the reflected light, surface inclination information in the vicinity of the measured portion is calculated. And a fourth calculating step of calculating an error between the surface tilt information of the measured part and the surface tilt information near the measured part, wherein the error is within a predetermined range. 4. The information acquisition method according to claim 3, wherein when the value is within, the provisional distance information of the measured part is output as true distance information of the measured part. 5. The fourth calculating step calculates the error for each of a plurality of provisional distance information of the measured part, and the calculating step calculates the measured value when the error is minimized. The information acquisition method according to claim 4, wherein the temporary distance information of the unit is set as true distance information of the measured unit. 6. The second calculating step includes calculating the temporary distance information in the vicinity of the measured portion in the vicinity of an extended surface of the measured portion based on the surface inclination information of the measured portion. The information acquisition method according to claim 4 or 5, wherein 7. The imaging step includes imaging the reflected light from the measured part and the reflected light from a plurality of locations near the measured part. The fourth calculating step includes calculating the reflected light from the measured part. In a plurality of locations near the target, the error between the temporary surface inclination information of the measured part and the temporary surface inclination information near the measured part is calculated, respectively, wherein the sum of squares of the error is calculated. 7. The information acquisition method according to claim 4, wherein the provisional distance information of the measured part in the case of the minimum is true distance information of the measured part. 8. The irradiating step includes irradiating the light having different wavelengths to the measured portion and the vicinity of the measured portion of the object at each of the irradiation positions, and substantially irradiating the light at each of the irradiation positions. Simultaneously irradiating the object with the light, the imaging step has a wavelength selecting means for selectively transmitting each of the different wavelength light, the light from the object at the respective irradiation position from the object 8. The information acquisition method according to claim 1, wherein each of the reflected light is imaged. 9. An image capturing apparatus for acquiring distance information to an object, comprising: an irradiation unit that irradiates the object with light from two optically different irradiation positions; and an irradiation unit that irradiates the object with light. An imaging unit that optically captures the reflected light of the light on the object by the light emitted from the two irradiation positions at the same optical position as the one; and a measurement of the object imaged by the imaging unit Based on the reflected light of the part and the reflected light from the vicinity of the part to be measured,
An image processing apparatus for calculating information on a distance to the measured section. 10. A control unit that synchronizes a light emission timing at which the irradiation unit irradiates the light and an imaging timing at which the imaging unit images the reflected light at each of the irradiation positions. The image pickup device according to claim 9. 11. The irradiating unit irradiates the light having a different wavelength at each of the irradiation positions, and irradiates the light to the object substantially simultaneously at each of the irradiation positions; Further comprising: a spectroscopic unit that separates the light reflected by the object into light having each of the different wavelengths as a main wavelength component, wherein the imaging unit captures each of the separated lights. The image capturing device according to claim 9. 12. The image pickup apparatus according to claim 11, wherein the light splitting unit has a plurality of optical filters mainly transmitting each of the lights having the different wavelengths. 13. An image processing apparatus for processing an image obtained by imaging an object, comprising: an input unit configured to input image data of respective lights emitted from two irradiation positions based on reflected light from the object. A storage unit that stores the input image data; and a distance information to the measured unit and the measured unit based on the measured data of the object and data near the measured unit in the image data. An image processing apparatus comprising: a calculating unit that calculates surface inclination information; and an output unit that outputs the distance information and the surface inclination information calculated by the calculating unit. 14. The image data is data captured by an imaging unit having a plurality of pixels that receive the reflected light, and wherein the calculating unit irradiates each of the pixels from the two irradiation positions. The intensity of the reflected light of the light is extracted, and the distance information of the object is based on the intensity of the reflected light from the vicinity of the measured portion and the measured portion of each of the extracted lights for each pixel. The image processing apparatus according to claim 13, wherein the distribution of the surface inclination information and the distribution of the surface inclination information are calculated. 15. The calculation unit calculates three-dimensional information of the object based on the distribution of the distance information and the distribution of the plane inclination information, and the output unit calculates the three-dimensional information of the object calculated by the calculation unit. The image processing device according to claim 14, wherein the image processing device outputs three-dimensional information. 16. The method according to claim 16, wherein the calculating unit assumes temporary distance information to the measured unit based on an intensity of reflected light from the measured unit and an incident angle of the reflected light. First to calculate the surface inclination information of the part
Calculating means, the temporary distance information to the measured part, and second calculating means for calculating temporary distance information near the measured part based on the surface inclination information of the measured part, Based on the provisional distance information in the vicinity of the measured portion, the intensity of reflected light from the vicinity of the measured portion, and the incident angle of the reflected light, surface inclination information in the vicinity of the measured portion is calculated. A third calculating means, and a fourth calculating means for calculating an error between the surface inclination information of the measured part and the surface inclination information near the measured part, wherein the error is within a predetermined range. The image processing apparatus according to claim 13, wherein when the value is within, the provisional distance information of the measured section is output as true distance information of the measured section. 17. The fourth calculating means calculates the error for each of a plurality of temporary distance information of the measured part, and the calculating part calculates the measured value when the error is minimized. 17. The image processing apparatus according to claim 16, wherein provisional distance information of the section is set as true distance information of the measured section. 18. The tentative distance information in the vicinity of the measured part in the vicinity where the surface of the measured part is extended, based on the surface inclination information of the measured part. The method for acquiring information according to claim 16, wherein the method is performed. 19. The input unit receives the reflected light from the measured unit and the image data based on the reflected lights from a plurality of locations near the measured unit. At a plurality of locations near the measured part, errors of the temporary surface inclination information of the measured part and the temporary surface inclination information near the measured part are calculated, respectively, 19. The image processing apparatus according to claim 16, wherein the temporary distance information of the measured part when the sum of squares of the error is minimized is the true distance information of the measured part. . 20. The calculation unit detects an edge of the object based on image data of the object, wherein the calculation unit includes: a plurality of locations near the measured unit;
In the region where the image data of the object is divided into a plurality of regions with the edge of the object as a boundary, the data is located in the same region as the region where the data of the measured portion is located, at a location near the measured portion. 20. The image processing apparatus according to claim 19, wherein distance information of the measured section is calculated based on the temporary plane inclination information. 21. The calculation unit, wherein a difference between the intensity of the reflected light from the measured part and the intensity of the reflected light from the vicinity of the measured part among a plurality of locations near the measured part is determined. 20. The image processing apparatus according to claim 19, wherein distance information of the measured section is calculated based on the provisional plane inclination information at a location near the measured section within a predetermined range.