Method for detecting large size and passenger vehicles from fixed cameras

A computer program product comprising a non-transitory computer readable memory storing instructions for performing a method of:

• receiving video data from a sequence of frames taken from an associated image capture device monitoring a parking area;
• in response to detecting an object in a current frame, associating the detected object as a candidate region where a newly parked vehicle may exist;
• in response to a size of the candidate region meeting or exceeding a size threshold, performing a sliding window search limited to the candidate region off each frame to extract object features of the detected candidate region from each of multiple windows;
• applying the extracted object features of each window to a first type vehicle classifier trained to classify larger vehicles that are a size capable of being divided into multiple parts each being in a different window of the sliding window searches;
• acquiring a first score from the first vehicle classifier indicative of a degree that the extracted object features match a trained vehicle of the first vehicle classifier;
• in response to the first score not meeting or exceeding the first confidence threshold, associating the newly parked vehicle with a large vehicle of a size that extends beyond the bounds of a single parking space;
• in response to the score not meeting the confidence threshold, ruling out the larger vehicle and associating the detected object as a candidate region where one or more of a small vehicle and shadow may exist;
• also in response to the first score not meeting or exceeding the first confidence threshold, for each window, applying the extracted object features to a second type vehicle classifier trained to classify vehicles that are smaller-sized than the large vehicle;
• acquiring a second score from the second type vehicle classifier indicative of a degree that the extracted object features match a trained vehicle of the second vehicle type;
• in response to the second score meeting or exceeding a second confidence threshold indicative of a degree that the object features match a trained second vehicle of the second vehicle classifier, associating the newly parked vehicle with one or more small vehicles;
• in response to the second score not meeting or exceeding the second confidence threshold, associating the candidate region as not containing a vehicle;
• and
• providing information regarding an occupancy of the parking space to a user device base on the associations.

A monitoring system for detecting a vehicle, the system comprising a vehicle detection device including a processor configured to:

• receive video data from a sequence of frames taken from an associated image capture device monitoring a parking area;
• in response to detecting an object in a current frame, associate the detected object as a candidate region where a newly parked vehicle may exist;
• in response to a size of the candidate region meeting or exceeding a size threshold, perform a sliding window search limited to the candidate region of each frame to extract object features of the detected candidate region from each of multiple windows;
• apply the extracted object features of each window to a first type vehicle classifier trained to classify larger vehicles that can be divided into multiple parts each in a different window of the sliding window search;
• acquire a first score from the first vehicle classifier indicative of a degree that the extracted object features match a trained vehicle of the first vehicle classifier;
• in response to the first score meeting or exceeding a first confidence threshold, associate the newly parked vehicle with a large vehicle of a size that extends beyond the bounds of a single parking space;
• in response to the first score not meeting or exceeding the first confidence threshold, rule out the large vehicle and associate the detected object as a candidate region where one or more of a small vehicle and shadow may exist;
• also in response to the first score not meeting or exceeding the first confidence threshold, for each window, apply the object features to a second type vehicle classifier trained to classify vehicles that are smaller size than the large vehicle;
• acquire a second score from the second type vehicle classifier indicative of a degree that the extracted object features match a trained vehicle of the second vehicle type;
• in response to the second score meeting or exceeding a second confidence threshold indicative of a degree that the object features match a trained second vehicle of the second vehicle classifier, associate the detected object with one or more small vehicles occupying the single one or more parking spaces;
• in response to the second score not meeting or exceeding the second confidence threshold, associate the parking space as not containing a vehicle;
• and
• provide information regarding an occupancy of the parking space to a user device base on the associations.