DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-3 and 5-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Grundhofer et al. (US 2016/0134851 A1) in view of Garcia et al. (US 2011/0205340 A1).
Regarding claim 1, Grundhofer discloses a method of camera calibration using active laser projection, comprising:
providing a camera calibration system (10), which comprises a camera (120a, 120b) and a plurality of laser emitters (110) (Fig. 1; [0034]);
operating the camera calibration system to cause the laser emitters to project corresponding plurality of laser light spots (151) on two planes (161 and/or 162 – where “the projection surface 161 may include multiple surfaces at different depths or locations relative to one another”) (Fig. 1; [0027]; [0034]-[0035]; [0054], lines 1-2);
obtaining image coordinates of the laser light spots through image processing ([0028]; [0054], last 5 lines; [0065], last 8 lines); and
calculating three-dimensional coordinates of the laser light spots using a pinhole imaging principle according to known intrinsic parameters of the camera and the image coordinates of the laser light spots to obtain a perspective projection matrix ([0028]-[0029]; [0075]-[0076] – “the processor may triangulate the 3D projection position for each element based on the element position within the projected calibration image and the known camera locations and orientations”).
Grundhofer does not appear to explicitly disclose obtaining multiple degrees of freedom of the camera accordingly, however, it is noted that one of ordinary skill in the art would recognize that such external camera parameters may be obtained using the three-dimensional coordinates, image projections and the derived perspective projection matrix.
However, Garcia, in the same field of endeavor of camera calibration systems and methods, discloses calculating multiple degrees of freedom of a camera ({C} in Fig. 1) accordingly ([0008]-[0011]; [0014]).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Grundhofer with a calibration system that is able to determine multiple degrees of freedom of the camera, improving the accuracy of the imaging process while reducing the complexity of the calibration system.
Regarding claim 2, Grundhofer in view of Garcia discloses the method of camera calibration using the active laser projection of claim 1, as outlined above, and further discloses wherein when X and Y coordinates of any laser light spot in a camera coordinate system are known, a Z coordinate is calculated through following formula (1) of a pinhole imaging and similar triangle principle,
Z
=
X
f
(
u
-
c
x
)
d
=
Y
f
(
v
-
c
y
)
d
f
o
r
m
u
l
a
(
1
)
wherein
(
X
,
Y
,
Z
)
are coordinates of any laser light spot projected on the two planes, and
(
u
,
v
)
are coordinates of the laser light spot on an image plane, and
f
is a focal length, and
d
is a pixel size, and
c
x
,
c
y
are coordinates of an origin of the image plane in a pixel coordinate system, wherein the known intrinsic parameters of the camera are the focal length
f
and image center coordinates
c
x
,
c
y
(Grundhofer: [0028]-[0029]; [0075]-[0076] – “projection characteristics of the laser projector are represented by a pinhole approximation for a pinhole device” where one of ordinary skill in the art would recognize the “pinhole approximation” as implying formula 1 to obtain a Z coordinate of the light spot in the camera coordinate system).
Regarding claim 3, Grundhofer in view of Garcia discloses the method of camera calibration using the active laser projection of claim 2, as outlined above, and further discloses calculating an equation of the two planes using the three-dimensional coordinates of the laser light spots (Garcia: [0011] – where the 3D data points are interpreted as the laser light spots).
Regarding claim 5, Grundhofer in view of Garcia discloses the camera correction method using the active laser projection of claim 1, as outlined above, and further discloses calculating roll, yaw, pitch and a camera height from a ground using the three mutually perpendicular vectors (Garcia: [0010]; [0048]; see claim 17).
Regarding claim 6, Grundhofer in view of Garcia discloses the method of camera calibration using the active laser projection of claim 3, as outlined above, but does not explicitly disclose wherein it is assumed that a plane equation is following formula (2), and there are
n
points in total on the plane, and
n
laser light spots (Xi,Yi,Zi) are put into the following formula (2) and write it in matrix form to obtain following formula (3), wherein i=1, 2, 3, ... n, and then a least squares method of following formula (4) is used to solve the equation of the two planes (Garcia: [0037]-[0038]; [0044]),
a
x
+
b
y
+
c
z
=
1
f
o
r
m
u
l
a
(
2
)
X
1
Y
1
Z
1
X
2
Y
2
Z
2
⋮
X
n
⋮
Y
n
⋮
Z
n
a
b
c
=
1
1
⋮
1
,
n
≥
3
f
o
r
m
u
l
a
(
3
)
a
b
c
=
X
1
Y
1
Z
1
X
2
Y
2
Z
2
⋮
X
n
⋮
Y
n
⋮
Z
n
T
X
1
Y
1
Z
1
X
2
Y
2
Z
2
⋮
X
n
⋮
Y
n
⋮
Z
n
-
1
X
1
Y
1
Z
1
X
2
Y
2
Z
2
⋮
X
n
⋮
Y
n
⋮
Z
n
T
1
1
⋮
1
f
o
r
m
u
l
a
(
4
)
.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Grundhofer et al. (US 2016/0134851 A1) in view of Garcia et al. (US 2011/0205340 A1) further in view of Nakano et al. (US 2022/0180563 A1).
Regarding claim 4, Grundhofer in view of Garcia discloses the method of camera calibration using the active laser projection of claim 3, as outlined above, but does not explicitly disclose obtaining three mutually perpendicular vectors using normal vectors of the two planes.
However, Nakano, in the same field of endeavor of camera calibration systems and methods, discloses obtaining three mutually perpendicular vectors using normal vectors of two planes (Fig. 3; Abstract; [0033]-[0034]; [0044]-[0046]).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Grundhofer in view of Garcia with a calibration method which obtains three mutually perpendicular vectors using normal vectors of two planes, providing a simpler calibration system and method which can more accurately calculate internal and external parameters of a camera (Nakano: [0021]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MAHER YAZBACK whose telephone number is (703)756-1456. The examiner can normally be reached Monday - Friday 8:30 am - 5:30 pm.
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/MAHER YAZBACK/Examiner, Art Unit 2877
/MICHELLE M IACOLETTI/Supervisory Patent Examiner, Art Unit 2877
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