Granted Patent B2

US 8,666,117 · App. 13/441,253 · Granted Mar 4, 2014

Abstract

Claims (78)

1. A method for determining a parking violation, the method comprising:

receiving video data as a sequence of frames provided by an associated image capture device;

defining a location of an exclusion zone in the video data;

detecting a vehicle located in the defined exclusion zone;

determining a duration that the detected vehicle is in the exclusion zone based on a number of the sequence of frames including the detected vehicle;

comparing the duration to a threshold; and,

in response to the duration meeting the threshold, indicating a parking violation,

wherein the threshold is dependent on a type of exclusion zone being monitored.

2. The method of claim 1 , where in the detecting of a vehicle includes:

determining a background in an initial frame of the video data;

determining a background in a select frame by applying a predetermined updating process;

subtracting the background of the select frame from the select frame to obtain an image difference;

classifying the pixels in the image difference as foreground or background pixels; and,

classifying the pixels in the foreground as vehicle or non-vehicle pixels.

3. The method of claim 2 , wherein the determining the background in the select frame includes:

applying a predetermined updating factor p in an algorithm for each pixel in the select frame, wherein the updating factor p varies depending on a classification of a pixel belonging to the foreground or the background pixels in the current frame.

4. The method of claim 2 , wherein the determining the background in the select frame includes:

computing a function B t+1 =ρ*F t+1 +(1−ρ)*B t , wherein B t is the background at time t, F t+1 is a frame at time t+1, and p is an image updating factor for a pixel, wherein the updating factor p is selected from a group consisting:

a “0” value for pixels belonging to a vehicle;

a “1” value for pixels belonging to a location previously occupied by a vehicle in a corresponding location of the initial frame; and,

a value 0≦p≦1 for all other pixels.

5. The method of claim 2 , where the classifying the pixels in the foreground includes:

applying a threshold to the image difference;

in response to the image difference meeting the threshold, classifying the pixel as belonging to a foreground.

6. The method of claim 2 , wherein the detecting the vehicle further includes:

applying morphological operations to the foreground image; and,

in response to the morphological operations, classifying the pixel as belonging to a vehicle.

7. The method of claim 1 , wherein the defining the location of the exclusion zone includes:

receiving input designating the exclusion zone in the video data with a boundary.

8. The method of claim 1 , wherein the defining the location of the exclusion zone includes:

generating a model associating a three-dimensional location in an actual area of the exclusion zone to a two-dimensional pixel coordinate (x, y) in the video data; and,

defining a location of the exclusion zone by mapping actual physical coordinates to pixel coordinates in the video data.

9. The method of claim 1 , wherein the determining the duration includes:

using the background estimate, computing a number of frames in the sequence of frames that the vehicle is stationary; and,

converting the number of frames to a time duration.

10. The method of claim 9 , wherein the computing the number of frames includes:

determining a first frame having an updating factor p being equal to “0” for a select pixel (i,j) belonging to the vehicle at a select location;

determining the number of frames following the first frame having the updating factor being equal to “0” for pixels located at corresponding locations to the first frame; and,

associating the first frame as a start time and the number of frames as a current time.

11. The method of claim 1 further comprising:

comparing the duration to a threshold;

in response to the duration meeting the threshold, determining if a parking condition is met; and,

in response to the parking condition being met, indicating that a parking violation is detected.

12. The method of claim 1 further comprising:

communicating the parking violation to a user device.

13. A computer program product comprising tangible media which encodes instructions for performing the method of claim 1 .

14. A system for determining parking availability comprising:

a parking violation determination device comprising memory which stores instructions for performing the method of claim 1 and a processor, in communication with the memory for executing the instructions.

15. A system for determining a parking violation, the system comprising a parking violation determination device in communication with an associated image capture device adapted to monitor an exclusion zone over a duration of time, the parking violation determination device including:

a video capture module adapted to receive video data from the associated image capture device and corresponding to a sequence of frames each capturing the exclusion zone;

an exclusion zone detection module adapted to define a location of the exclusion zone in the video data;

a vehicle detection module adapted to detect a vehicle located in the defined exclusion zone;

a duration determination module adapted to:

determine a duration that a vehicle is in the exclusion zone based on a number of the sequence of frames including the vehicle pixels,

compare the duration to a threshold, and

in response to the duration meeting the threshold, indicate a parking violation; and,

a processor adapted to implement the modules.

16. The system according to claim 15 , wherein the vehicle detection module is further adapted to:

determine a background in an initial frame of the video data;

determine a background in a select frame by applying a predetermined updating process;

subtract the background of the select frame from the background of the initial frame to obtain an image difference;

classify pixels in the image difference as belonging to one of foreground and background pixels; and,

classify the pixels in the foreground image as one of vehicle and non-vehicle pixels.

17. The system of claim 16 , wherein the background estimation module is further adapted to:

apply a predetermined updating factor p in an algorithm computed for each pixel in the select frame, wherein the updating factor p varies depending on a classification of a pixel belonging to the foreground or the background pixels in a current frame.

18. The system of claim 16 , wherein the vehicle detection module is adapted:

compute the function B t+1 =ρ*F t+1 +(1−ρ)*B t , wherein B t is the background at time t, F t+1 is a frame at time t+1, and p is an image updating factor for a pixel, wherein the updating factor p is selected from a group consisting:

a “0” value if a vehicle is detected at the pixel location;

a “1” value if another object is detected at a pixel location previously occupied by a vehicle; and,

a value 0≦p≦1 for all other pixels.

19. The system of claim 16 , wherein the duration determination module is further adapted to:

determine a first frame having the updating factor p being equal to “0” for a select pixel (i,j) belonging to the vehicle at a select location;

determine a number of frames following the first frame having the updating factor being equal to “0” for pixels located at corresponding locations to the first frame; and,

convert the number of frames to the duration.

20. The system of claim 15 , wherein the vehicle detection module is adapted to:

apply the image difference to a threshold; and,

in response to the image difference meeting the threshold, classify the pixel as belonging to a vehicle,

wherein the threshold is dependent on a type of exclusion zone being monitored.

Assignments (8)