Device for determining disappearing direction and method thereof, apparatus for video camera calibration and method thereof

1. A device for determining a disappearing direction, comprising:

circuitry configured to:

detect a plurality of edges of one or more objects in a video image to obtain corresponding line segments on the one or more objects;

group the line segments into a plurality of line segment groups by a predetermined rule, initially estimate the disappearing direction according to the plurality of the line segment groups, and obtain an initial estimation of the disappearing direction;

select at least one line segment which is closest to the initial estimation from a predetermined number of the line segment groups among all the line segment groups; and

determine the disappearing direction using the selected at least one line segment, wherein the circuitry is configured to

initially estimate the disappearing direction by using a second disappearing direction perpendicular to the disappearing direction to be estimated, and

combine the line segment groups into one or more combinations, each combination including at least two groups.

2. The device for determining the disappearing direction according to claim 1 , wherein, the predetermined rule is: line segments of a same object in the video image are grouped into a same line segment group.

3. The device for determining the disappearing direction according to claim 1 ,

wherein, each combination includes a first group and a second group, and

wherein the circuitry is configured to

for each combination in a predetermined number of combinations in all combinations, calculate an outer product of edge plane normal vectors of every two line segments respectively of the first group and the second group, and seek an inner product of the calculated outer product and the second disappearing direction; and

compare all calculated inner products for the predetermined number of combinations with a first threshold, and determine a direction of an edge plane normal vector corresponding to any inner product smaller than the first threshold as an initial value of the initial estimation of the disappearing direction.

4. The device for determining the disappearing direction according to claim 3 ,

wherein, the circuitry is configured to select, from determined initial values, a final initial value with a maximum number of support groups as a final value of the initial estimation of the disappearing direction, and

wherein, for each support group, a minimum inner product in all the inner products calculated with the initial value and edge plane normal vectors of all line segments in the support group, is smaller than a second threshold.

5. The device for determining the disappearing direction according to claim 4 ,

wherein, when there are more than one initial value with a same maximum number of support groups, the circuitry is configured to select the final initial value which makes a target function smallest as the final value of the initial estimation, and

wherein, the target function includes a measurement of a perpendicular degree between the initial value and the second disappearing direction, and a measurement of a parallel degree between the initial value and line segments most parallel to the initial value in other support groups.

6. The device for determining the disappearing direction according to claim 5 ,

wherein, the target function is:

f

⁡

(

OX

)

=

OX

·

OZ

+

1

N

⁡

(

S

)

⁢

∑

i

∈

S

⁢

min

j

⁢

(

OX

·

L

j

)

,

⁢

and

wherein OX is representative of the initial value of the initial estimation of the disappearing direction, OZ is representative of the second disappearing direction, N(S) is the number of support groups,

∑

i

∈

S

is to sum all support groups,

min

j

⁢

(

OX

·

L

j

)

is to seek a minimum value of inner products of the initial value of OX and edge plane normal vectors of all segments Lj in support group i.

7. A method of determining a disappearing direction, comprising:

detecting a plurality of edges of one or more objects in a video image to obtain corresponding line segments on the one or more objects;

grouping the line segments into a plurality of line segment groups by a predetermined rule, and initially estimating the disappearing direction according to the plurality of the line segment groups to obtain an initial estimation of the disappearing direction;

selecting at least one line segment which is closest to the initial estimation from a predetermined number of the line segment groups among all the line segment groups; and

determining the disappearing direction by using the selected at least one line segments, wherein

the disappearing direction is initially estimated by using a second disappearing direction perpendicular to the disappearing direction to be estimated, and

the line segment groups are combined into one or more combinations, each combination including at least two groups.

8. A non-transitory computer program product, comprising program codes which, when executed by a processor of a computer, cause the processor to perform a method comprising:

detecting a plurality of edges of one or more objects in an input video image to obtain corresponding line segments on the one or more objects;

grouping the line segments into a plurality of line segment groups by a predetermined rule, and initially estimating the disappearing direction according to the plurality of the line segment groups to obtain an initial estimation of the disappearing direction;

selecting at least one line segment which is closest to the initial estimation from a predetermined number of the line segment groups among all the line segment groups; and

determining a disappearing direction by using the selected at least one line segment, wherein

the disappearing direction is initially estimated by using a second disappearing direction perpendicular to the disappearing direction to be estimated, and

the line segment groups are combined into one or more combinations, each combination including at least two groups.