diff --git a/frigate/track/norfair_tracker.py b/frigate/track/norfair_tracker.py index 04ec21aac..53cdaad6f 100644 --- a/frigate/track/norfair_tracker.py +++ b/frigate/track/norfair_tracker.py @@ -17,12 +17,13 @@ from frigate.ptz.autotrack import PtzMotionEstimator from frigate.track import ObjectTracker from frigate.types import PTZMetricsTypes from frigate.util.image import intersection_over_union -from frigate.util.object import average_boxes +from frigate.util.object import average_boxes, median_of_boxes logger = logging.getLogger(__name__) -THRESHOLD_STATIONARY_IOU_AVERAGE = 0.6 +THRESHOLD_ACTIVE_IOU = 0.2 +THRESHOLD_STATIONARY_IOU = 0.6 MAX_STATIONARY_HISTORY = 10 @@ -146,6 +147,7 @@ class NorfairTracker(ObjectTracker): # tracks the current position of the object based on the last N bounding boxes # returns False if the object has moved outside its previous position def update_position(self, id: str, box: list[int, int, int, int]): + xmin, ymin, xmax, ymax = box position = self.positions[id] self.stationary_box_history[id].append(box) @@ -158,11 +160,9 @@ class NorfairTracker(ObjectTracker): box, average_boxes(self.stationary_box_history[id]) ) - xmin, ymin, xmax, ymax = box - - # if the iou drops below the threshold - # assume the object has moved to a new position and reset the computed box - if avg_iou < THRESHOLD_STATIONARY_IOU_AVERAGE: + # object has minimal or zero iou + # assume object is active + if avg_iou < THRESHOLD_ACTIVE_IOU: self.positions[id] = { "xmins": [xmin], "ymins": [ymin], @@ -175,6 +175,33 @@ class NorfairTracker(ObjectTracker): } return False + # object has iou below threshold, check median to reduce outliers + if avg_iou < THRESHOLD_STATIONARY_IOU: + median_iou = intersection_over_union( + ( + position["xmin"], + position["ymin"], + position["xmax"], + position["ymax"], + ), + median_of_boxes(self.stationary_box_history[id]), + ) + + # if the median iou drops below the threshold + # assume object is no longer stationary + if median_iou < THRESHOLD_STATIONARY_IOU: + self.positions[id] = { + "xmins": [xmin], + "ymins": [ymin], + "xmaxs": [xmax], + "ymaxs": [ymax], + "xmin": xmin, + "ymin": ymin, + "xmax": xmax, + "ymax": ymax, + } + return False + # if there are less than 10 entries for the position, add the bounding box # and recompute the position box if len(position["xmins"]) < 10: diff --git a/frigate/util/object.py b/frigate/util/object.py index 81940f303..66810d5e7 100644 --- a/frigate/util/object.py +++ b/frigate/util/object.py @@ -339,6 +339,12 @@ def average_boxes(boxes: list[list[int, int, int, int]]) -> list[int, int, int, return [np.mean(x_mins), np.mean(y_mins), np.mean(x_max), np.mean(y_max)] +def median_of_boxes(boxes: list[list[int, int, int, int]]) -> list[int, int, int, int]: + """Return a box that is the median of a list of boxes.""" + sorted_boxes = sorted(boxes, key=lambda x: area(x)) + return sorted_boxes[int(len(sorted_boxes) / 2.0)] + + def intersects_any(box_a, boxes): for box in boxes: if box_overlaps(box_a, box):