Information measuring method and information measuring system
An information measuring method is used for measuring installation information of a camera disposed over a plane with an installation height and oriented towards the plane with a shooting angle. The information measuring method includes steps of disposing a first reference point and a second reference point on the plane; measuring a first distance and a second distance between the first reference point, the second reference point and a third reference point; capturing an image including the first reference point, the second reference point and the third reference point; analyzing the image to define a first reference line and a second reference line; determining a first angle and a second angle according to the first reference line, the second reference line and a first normal line; and determining the installation height and/or the shooting angle according to the first distance, the second distance, the first angle and the second angle.
1. An information measuring method for measuring installation information of a camera, the camera being disposed over a plane with an installation height and oriented towards the plane with a shooting angle, the camera comprising a lens, the lens having an optical center, the information measuring method comprising:
disposing a first reference point and a second reference point on the plane, wherein a first normal line of the lens passes through the optical center and intersects with the plane at a third reference point;
measuring a first distance and a second distance between the first reference point, the second reference point and the third reference point;
capturing an image including the first reference point, the second reference point and the third reference point;
analyzing the image to define a first reference line and a second reference line, wherein the first reference line passes through the first reference point and the optical center, and the second reference line passes through the second reference point and the optical center;
determining a first angle and a second angle according to the first reference line, the second reference line and the first normal line; and
determining the installation height and/or the shooting angle according to the first distance, the second distance, the first angle and the second angle;
wherein the third reference point is located between the first reference point and the second reference point, the first reference point and the third reference point are spaced by the first distance, the second reference point and the third reference point are spaced by the second distance, the first angle is included between the first reference line and the first normal line, and the second angle is included between the second reference line and the first normal line;
wherein a second normal line of the plane passes through the optical center, the second normal line intersects with the plane at a fourth reference point, the first reference point is located between the third reference point and the fourth reference point, a third angle is included between the first reference line and the second normal line, the third angle, the shooting angle and the installation height are obtained by equations of:
tan
(
θ
3
)
=
{
1
-
D
1
D
2
[
tan
(
θ
1
+
θ
2
)
-
tan
(
θ
1
)
]
tan
(
θ
1
)
}
tan
(
θ
1
+
θ
2
)
;
θ
c
=
θ
1
+
θ
3
;
and
h
=
D
2
[
tan
(
θ
1
+
θ
2
+
θ
3
)
-
tan
(
θ
1
+
θ
3
)
]
;
Wherein θ1 represents the first angle, θ2 represents the second angle, θ3 represents the third angle, D1 represents the first distance, D2 represents the second distance, θc represents the shooting angle, and h represents the installation height.
2. The information measuring method of claim 1 , further comprising:
moving a position generator between the first reference point, the second reference point and the third reference point, so as to measure the first distance and the second distance by the position generator.
3. An information measuring method for measuring installation information of a camera, the camera being disposed over a plane with an installation height and oriented towards the plane with a shooting angle, the camera comprising a lens, the lens having an optical center, the information measuring method comprising:
disposing a first reference point and a second reference point on the plane, wherein a first normal line of the lens passes through the optical center and intersects with the plane at a third reference point;
measuring a first distance and a second distance between the first reference point, the second reference point and the third reference point;
capturing an image including the first reference point, the second reference point and the third reference point;
analyzing the image to define a first reference line and a second reference line, wherein the first reference line passes through the first reference point and the optical center, and the second reference line passes through the second reference point and the optical center;
determining a first angle and a second angle according to the first reference line, the second reference line and the first normal line; and
determining the installation height and/or the shooting angle according to the first distance, the second distance, the first angle and the second angle;
wherein the second reference point is located between the first reference point and the third reference point, the first reference point and the second reference point are spaced by the first distance, the second reference point and the third reference point are spaced by the second distance, the first angle is included between the first reference line and the second reference line, and the second angle is included between the second reference line and the first normal line;
wherein a second normal line of the plane passes through the optical center, the second normal line intersects with the plane at a fourth reference point, the first reference point is located between the second reference point and the fourth reference point, a third angle is included between the first reference line and the second normal line, the third angle, the shooting angle and the installation height are obtained by equations of:
tan
(
θ
3
)
=
{
1
-
D
1
D
2
[
tan
(
θ
1
+
θ
2
)
-
tan
(
θ
1
)
]
tan
(
θ
1
)
}
tan
(
θ
1
+
θ
2
)
;
θ
c
=
θ
1
+
θ
2
+
θ
3
;
and
h
=
D
2
[
tan
(
θ
1
+
θ
2
+
θ
3
)
-
tan
(
θ
1
+
θ
3
)
]
;
Wherein θ1 represents the first angle, θ2 represents the second angle, θ3 represents the third angle, D1 represents the first distance, D2 represents the second distance, θc represents the shooting angle, and h represents the installation height.
4. The information measuring method of claim 3 , further comprising:
moving a position generator between the first reference point, the second reference point and the third reference point, so as to measure the first distance and the second distance by the position generator.
5. An information measuring method for measuring installation information of a camera, the camera being disposed over a plane with an installation height and oriented towards the plane with a shooting angle, the camera comprising a lens, the lens having an optical center, the information measuring method comprising:
disposing a first reference point and a second reference point on the plane, wherein a first normal line of the lens passes through the optical center and intersects with the plane at a third reference point;
measuring a first distance and a second distance between the first reference point, the second reference point and the third reference point;
capturing an image including the first reference point, the second reference point and the third reference point;
analyzing the image to define a first reference line and a second reference line, wherein the first reference line passes through the first reference point and the optical center, and the second reference line passes through the second reference point and the optical center;
determining a first angle and a second angle according to the first reference line, the second reference line and the first normal line; and
determining the installation height and/or the shooting angle according to the first distance, the second distance, the first angle and the second angle;
wherein the first reference point is located between the second reference point and the third reference point, the first reference point and the third reference point are spaced by the first distance, the second reference point and the first reference point are spaced by the second distance, the first angle is included between the first reference line and the first normal line, and the second angle is included between the second reference line and the first reference line;
wherein a second normal line of the plane passes through the optical center, the second normal line intersects with the plane at a fourth reference point, the third reference point is located between the first reference point and the fourth reference point, a third angle is included between the first normal line and the second normal line, the third angle, the shooting angle and the installation height are obtained by equations of:
tan
(
θ
3
)
=
{
1
-
D
1
D
2
[
tan
(
θ
1
+
θ
2
)
-
tan
(
θ
1
)
]
tan
(
θ
1
)
}
tan
(
θ
1
+
θ
2
)
;
θ
c
=
θ
3
;
and
h
=
D
2
[
tan
(
θ
1
+
θ
2
+
θ
3
)
-
tan
(
θ
1
+
θ
3
)
]
;
Wherein θ1 represents the first angle, θ2 represents the second angle, θ3 represents the third angle, D1 represents the first distance, D2 represents the second distance, θc represents the shooting angle, and h represents the installation height.
6. The information measuring method of claim 5 , further comprising:
moving a position generator between the first reference point, the second reference point and the third reference point, so as to measure the first distance and the second distance by the position generator.