Camera calibration based on moving vehicle line segments

1. A computer-implemented method, comprising:

accessing video data for a geographic area captured by a video camera;

processing the video data to detect a plurality of moving vehicles in the video data;

defining a detection area based on the plurality of moving vehicles;

extracting a plurality of line segments for each of the plurality of vehicles detected in the video data;

estimating a plurality of vanishing points based on at least a subset of the plurality of line segments; and

determining a camera calibration based on the plurality of vanishing points,

wherein extracting a plurality of line segments includes:

detecting a plurality of edges of one of the plurality of vehicles within the detection area; and

identifying straight line segments within the detection area.

2. The computer-implemented method of claim 1 , wherein

identifying the straight line segments comprises identifying the straight line segments using one of a Hough transform and a Line Segment Detector.

3. The computer-implemented method of claim 1 , further comprising

determining an orientation for each of the plurality of line segments; and

grouping line segments into one of a plurality of groups based on the orientation of the line segments.

4. The computer-implemented method of claim 3 , wherein the plurality of groups includes a first group and a second group, the line segments in the first group having line segments that are substantially perpendicular to the line segments of the second group.

5. The computer-implemented method of claim 1 , wherein determining a camera calibration includes:

generating an inverse perspective mapping based on at least two of the vanishing points.

6. The computer-implemented method of claim 1 , wherein the method is performed in the video camera.

7. The computer-implemented method of claim 1 , further comprising:

applying the camera calibration to image data captured by the video camera.

8. An apparatus, comprising:

a memory storing a set of instructions; and

a processor, configured to execute the stored set of instructions to perform operations comprising:

accessing video data for a geographic area captured by a video camera;

processing the video data to detect a plurality of moving vehicles in the video data;

defining a detection area based on the plurality of moving vehicles;

extracting a plurality of line segments for each of the plurality of vehicles detected in the video data;

estimating a plurality of vanishing points based on at least a subset of the plurality of line segments; and

determining a camera calibration based on the plurality of vanishing points,

wherein extracting a plurality of line segments includes:

detecting a plurality of edges of one of the plurality of vehicles within the detection area; and

identifying straight line segments within the detection area.

9. The apparatus of claim 8 , wherein

identifying the straight line segments comprises identifying the straight line segments using one of a Hough transform and a Line Segment Detector.

10. The apparatus of claim 8 , the method further comprising

determining an orientation for each of the plurality of line segments; and

grouping line segments into one of a plurality of groups based on the orientation of the line segments.

11. The apparatus of claim 10 , wherein the plurality of groups includes a first group and a second group, the line segments in the first group having line segments that are perpendicular to the line segments of the second group.

12. The apparatus of claim 8 , wherein determining a camera calibration includes:

generating an inverse perspective mapping based on at least two of the vanishing points.

13. The apparatus of claim 8 , wherein the method is performed in the video camera.

14. The apparatus of claim 8 , the method further comprising:

applying the camera calibration to image data captured by the video camera.

15. A non-transitory computer-readable medium storing a set of instructions, executable by a processor to perform operations comprising:

accessing video data for a geographic area captured by a video camera;

processing the video data to detect a plurality of moving vehicles in the video data;

defining a detection area based on the plurality of moving vehicles;

extracting a plurality of line segments for each of the plurality of vehicles detected in the video data;

estimating a plurality of vanishing points based on at least a subset of the plurality of line segments; and

determining a camera calibration based on the plurality of vanishing points,

wherein extracting a plurality of line segments includes:

detecting a plurality of edges of one of the plurality of vehicles within the detection area; and

identifying straight line segments within the detection area.

16. The computer-readable medium of claim 15 , wherein

identifying the straight line segments comprises identifying the straight line segments using one of a Hough transform and a Line Segment Detector.

17. The computer-readable medium of claim 15 , the method further comprising

determining an orientation for each of the plurality of line segments; and

grouping line segments into one of a plurality of groups based on the orientation of the line segments.

18. The computer-readable medium of claim 17 , wherein the plurality of groups includes a first group and a second group, the line segments in the first group having line segments that are perpendicular to the line segments of the second group.

19. The computer-readable medium of claim 15 , wherein determining a camera calibration includes:

generating an inverse perspective mapping based on at least two of the vanishing points.

20. The computer-readable medium of claim 15 , the method further comprising:

applying the camera calibration to image data captured by the video camera.