2025-03-26 11:26:55 +08:00

114 lines
5.0 KiB
Python

# Ultralytics 🚀 AGPL-3.0 License - https://ultralytics.com/license
from time import time
import numpy as np
from ultralytics.solutions.solutions import BaseSolution, SolutionAnnotator, SolutionResults
from ultralytics.utils.plotting import colors
class SpeedEstimator(BaseSolution):
"""
A class to estimate the speed of objects in a real-time video stream based on their tracks.
This class extends the BaseSolution class and provides functionality for estimating object speeds using
tracking data in video streams.
Attributes:
spd (Dict[int, float]): Dictionary storing speed data for tracked objects.
trkd_ids (List[int]): List of tracked object IDs that have already been speed-estimated.
trk_pt (Dict[int, float]): Dictionary storing previous timestamps for tracked objects.
trk_pp (Dict[int, Tuple[float, float]]): Dictionary storing previous positions for tracked objects.
region (List[Tuple[int, int]]): List of points defining the speed estimation region.
track_line (List[Tuple[float, float]]): List of points representing the object's track.
r_s (LineString): LineString object representing the speed estimation region.
Methods:
initialize_region: Initializes the speed estimation region.
process: Processes input frames to estimate object speeds.
store_tracking_history: Stores the tracking history for an object.
extract_tracks: Extracts tracks from the current frame.
display_output: Displays the output with annotations.
Examples:
>>> estimator = SpeedEstimator()
>>> frame = cv2.imread("frame.jpg")
>>> results = estimator.process(frame)
>>> cv2.imshow("Speed Estimation", results.plot_im)
"""
def __init__(self, **kwargs):
"""
Initialize the SpeedEstimator object with speed estimation parameters and data structures.
Args:
**kwargs (Any): Additional keyword arguments passed to the parent class.
"""
super().__init__(**kwargs)
self.initialize_region() # Initialize speed region
self.spd = {} # Dictionary for speed data
self.trkd_ids = [] # List for already speed-estimated and tracked IDs
self.trk_pt = {} # Dictionary for tracks' previous timestamps
self.trk_pp = {} # Dictionary for tracks' previous positions
def process(self, im0):
"""
Process an input frame to estimate object speeds based on tracking data.
Args:
im0 (np.ndarray): Input image for processing with shape (H, W, C) for RGB images.
Returns:
(SolutionResults): Contains processed image `plot_im` and `total_tracks` (number of tracked objects).
Examples:
>>> estimator = SpeedEstimator()
>>> image = np.random.randint(0, 255, (480, 640, 3), dtype=np.uint8)
>>> results = estimator.process(image)
"""
self.extract_tracks(im0) # Extract tracks
annotator = SolutionAnnotator(im0, line_width=self.line_width) # Initialize annotator
# Draw speed estimation region
annotator.draw_region(reg_pts=self.region, color=(104, 0, 123), thickness=self.line_width * 2)
for box, track_id, cls in zip(self.boxes, self.track_ids, self.clss):
self.store_tracking_history(track_id, box) # Store track history
# Initialize tracking data for new objects
if track_id not in self.trk_pt:
self.trk_pt[track_id] = 0
if track_id not in self.trk_pp:
self.trk_pp[track_id] = self.track_line[-1]
# Prepare label with speed if available, otherwise use class name
speed_label = f"{int(self.spd[track_id])} km/h" if track_id in self.spd else self.names[int(cls)]
annotator.box_label(box, label=speed_label, color=colors(track_id, True)) # Draw bounding box
# Determine if object is crossing the speed estimation region
if self.LineString([self.trk_pp[track_id], self.track_line[-1]]).intersects(self.r_s):
direction = "known"
else:
direction = "unknown"
# Calculate speed for objects crossing the region for the first time
if direction == "known" and track_id not in self.trkd_ids:
self.trkd_ids.append(track_id)
time_difference = time() - self.trk_pt[track_id]
if time_difference > 0:
# Calculate speed based on vertical displacement and time
self.spd[track_id] = np.abs(self.track_line[-1][1] - self.trk_pp[track_id][1]) / time_difference
# Update tracking data for next frame
self.trk_pt[track_id] = time()
self.trk_pp[track_id] = self.track_line[-1]
plot_im = annotator.result()
self.display_output(plot_im) # Display output with base class function
# Return results with processed image and tracking summary
return SolutionResults(plot_im=plot_im, total_tracks=len(self.track_ids))