improve method for determining position

compares the centroid to a history of bounding boxes
This commit is contained in:
Blake Blackshear 2022-02-04 07:18:50 -06:00
parent 675f21e23a
commit 338e4004d4

View File

@ -20,7 +20,9 @@ class ObjectTracker:
def __init__(self, config: DetectConfig):
self.tracked_objects = {}
self.disappeared = {}
self.positions = {}
self.max_disappeared = config.max_disappeared
self.detect_config = config
def register(self, index, obj):
rand_id = "".join(random.choices(string.ascii_lowercase + string.digits, k=6))
@ -30,17 +32,71 @@ class ObjectTracker:
obj["motionless_count"] = 0
self.tracked_objects[id] = obj
self.disappeared[id] = 0
self.positions[id] = {
"xmins": [],
"ymins": [],
"xmaxs": [],
"ymaxs": [],
"xmin": 0,
"ymin": 0,
"xmax": self.detect_config.width,
"ymax": self.detect_config.height,
}
def deregister(self, id):
del self.tracked_objects[id]
del self.disappeared[id]
# tracks the current position of the object based on the last 10 bounding boxes
# returns False if the object has moved outside its previous position
def update_position(self, id, box):
position = self.positions[id]
xmin, ymin, xmax, ymax = box
# get the centroid
x = (xmax + xmin) / 2
y = (ymax + ymin) / 2
# if the centroid of this box is outside the computed bounding box
# assume the object has moved to a new position and reset the computed box
# TODO: should this only happen if there are a few boxes?
if (
x < position["xmin"]
or x > position["xmax"]
or y < position["ymin"]
or y > position["ymax"]
):
position = {
"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:
position["xmins"].append(xmin)
position["ymins"].append(ymin)
position["xmaxs"].append(xmax)
position["ymaxs"].append(ymax)
# by using percentiles here, we hopefully remove outliers
position["xmin"] = np.percentile(position["xmins"], 15)
position["ymin"] = np.percentile(position["ymins"], 15)
position["xmax"] = np.percentile(position["xmaxs"], 85)
position["ymax"] = np.percentile(position["ymaxs"], 85)
return True
def update(self, id, new_obj):
self.disappeared[id] = 0
if (
intersection_over_union(self.tracked_objects[id]["box"], new_obj["box"])
> 0.9
):
# update the motionless count if the object has not moved to a new position
if self.update_position(id, new_obj["box"]):
self.tracked_objects[id]["motionless_count"] += 1
else:
self.tracked_objects[id]["motionless_count"] = 0