Integrate ByteTracker and BoT-SORT trackers (#788)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>
Co-authored-by: Ayush Chaurasia <ayush.chaurarsia@gmail.com>
This commit is contained in:
Laughing
2023-02-16 00:23:03 +08:00
committed by GitHub
parent d99e04daa1
commit ed6c54da7a
24 changed files with 1635 additions and 19 deletions

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import copy
import cv2
import matplotlib.pyplot as plt
import numpy as np
class GMC:
def __init__(self, method='sparseOptFlow', downscale=2, verbose=None):
super().__init__()
self.method = method
self.downscale = max(1, int(downscale))
if self.method == 'orb':
self.detector = cv2.FastFeatureDetector_create(20)
self.extractor = cv2.ORB_create()
self.matcher = cv2.BFMatcher(cv2.NORM_HAMMING)
elif self.method == 'sift':
self.detector = cv2.SIFT_create(nOctaveLayers=3, contrastThreshold=0.02, edgeThreshold=20)
self.extractor = cv2.SIFT_create(nOctaveLayers=3, contrastThreshold=0.02, edgeThreshold=20)
self.matcher = cv2.BFMatcher(cv2.NORM_L2)
elif self.method == 'ecc':
number_of_iterations = 5000
termination_eps = 1e-6
self.warp_mode = cv2.MOTION_EUCLIDEAN
self.criteria = (cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, number_of_iterations, termination_eps)
elif self.method == 'sparseOptFlow':
self.feature_params = dict(maxCorners=1000,
qualityLevel=0.01,
minDistance=1,
blockSize=3,
useHarrisDetector=False,
k=0.04)
# self.gmc_file = open('GMC_results.txt', 'w')
elif self.method in ['file', 'files']:
seqName = verbose[0]
ablation = verbose[1]
if ablation:
filePath = r'tracker/GMC_files/MOT17_ablation'
else:
filePath = r'tracker/GMC_files/MOTChallenge'
if '-FRCNN' in seqName:
seqName = seqName[:-6]
elif '-DPM' in seqName or '-SDP' in seqName:
seqName = seqName[:-4]
self.gmcFile = open(f"{filePath}/GMC-{seqName}.txt")
if self.gmcFile is None:
raise ValueError(f"Error: Unable to open GMC file in directory:{filePath}")
elif self.method in ['none', 'None']:
self.method = 'none'
else:
raise ValueError(f"Error: Unknown CMC method:{method}")
self.prevFrame = None
self.prevKeyPoints = None
self.prevDescriptors = None
self.initializedFirstFrame = False
def apply(self, raw_frame, detections=None):
if self.method in ['orb', 'sift']:
return self.applyFeaures(raw_frame, detections)
elif self.method == 'ecc':
return self.applyEcc(raw_frame, detections)
elif self.method == 'sparseOptFlow':
return self.applySparseOptFlow(raw_frame, detections)
elif self.method == 'file':
return self.applyFile(raw_frame, detections)
elif self.method == 'none':
return np.eye(2, 3)
else:
return np.eye(2, 3)
def applyEcc(self, raw_frame, detections=None):
# Initialize
height, width, _ = raw_frame.shape
frame = cv2.cvtColor(raw_frame, cv2.COLOR_BGR2GRAY)
H = np.eye(2, 3, dtype=np.float32)
# Downscale image (TODO: consider using pyramids)
if self.downscale > 1.0:
frame = cv2.GaussianBlur(frame, (3, 3), 1.5)
frame = cv2.resize(frame, (width // self.downscale, height // self.downscale))
width = width // self.downscale
height = height // self.downscale
# Handle first frame
if not self.initializedFirstFrame:
# Initialize data
self.prevFrame = frame.copy()
# Initialization done
self.initializedFirstFrame = True
return H
# Run the ECC algorithm. The results are stored in warp_matrix.
# (cc, H) = cv2.findTransformECC(self.prevFrame, frame, H, self.warp_mode, self.criteria)
try:
(cc, H) = cv2.findTransformECC(self.prevFrame, frame, H, self.warp_mode, self.criteria, None, 1)
except Exception as e:
print(f'Warning: find transform failed. Set warp as identity {e}')
return H
def applyFeaures(self, raw_frame, detections=None):
# Initialize
height, width, _ = raw_frame.shape
frame = cv2.cvtColor(raw_frame, cv2.COLOR_BGR2GRAY)
H = np.eye(2, 3)
# Downscale image (TODO: consider using pyramids)
if self.downscale > 1.0:
# frame = cv2.GaussianBlur(frame, (3, 3), 1.5)
frame = cv2.resize(frame, (width // self.downscale, height // self.downscale))
width = width // self.downscale
height = height // self.downscale
# find the keypoints
mask = np.zeros_like(frame)
# mask[int(0.05 * height): int(0.95 * height), int(0.05 * width): int(0.95 * width)] = 255
mask[int(0.02 * height):int(0.98 * height), int(0.02 * width):int(0.98 * width)] = 255
if detections is not None:
for det in detections:
tlbr = (det[:4] / self.downscale).astype(np.int_)
mask[tlbr[1]:tlbr[3], tlbr[0]:tlbr[2]] = 0
keypoints = self.detector.detect(frame, mask)
# compute the descriptors
keypoints, descriptors = self.extractor.compute(frame, keypoints)
# Handle first frame
if not self.initializedFirstFrame:
# Initialize data
self.prevFrame = frame.copy()
self.prevKeyPoints = copy.copy(keypoints)
self.prevDescriptors = copy.copy(descriptors)
# Initialization done
self.initializedFirstFrame = True
return H
# Match descriptors.
knnMatches = self.matcher.knnMatch(self.prevDescriptors, descriptors, 2)
# Filtered matches based on smallest spatial distance
matches = []
spatialDistances = []
maxSpatialDistance = 0.25 * np.array([width, height])
# Handle empty matches case
if len(knnMatches) == 0:
# Store to next iteration
self.prevFrame = frame.copy()
self.prevKeyPoints = copy.copy(keypoints)
self.prevDescriptors = copy.copy(descriptors)
return H
for m, n in knnMatches:
if m.distance < 0.9 * n.distance:
prevKeyPointLocation = self.prevKeyPoints[m.queryIdx].pt
currKeyPointLocation = keypoints[m.trainIdx].pt
spatialDistance = (prevKeyPointLocation[0] - currKeyPointLocation[0],
prevKeyPointLocation[1] - currKeyPointLocation[1])
if (np.abs(spatialDistance[0]) < maxSpatialDistance[0]) and \
(np.abs(spatialDistance[1]) < maxSpatialDistance[1]):
spatialDistances.append(spatialDistance)
matches.append(m)
meanSpatialDistances = np.mean(spatialDistances, 0)
stdSpatialDistances = np.std(spatialDistances, 0)
inliesrs = (spatialDistances - meanSpatialDistances) < 2.5 * stdSpatialDistances
goodMatches = []
prevPoints = []
currPoints = []
for i in range(len(matches)):
if inliesrs[i, 0] and inliesrs[i, 1]:
goodMatches.append(matches[i])
prevPoints.append(self.prevKeyPoints[matches[i].queryIdx].pt)
currPoints.append(keypoints[matches[i].trainIdx].pt)
prevPoints = np.array(prevPoints)
currPoints = np.array(currPoints)
# Draw the keypoint matches on the output image
if 0:
matches_img = np.hstack((self.prevFrame, frame))
matches_img = cv2.cvtColor(matches_img, cv2.COLOR_GRAY2BGR)
W = np.size(self.prevFrame, 1)
for m in goodMatches:
prev_pt = np.array(self.prevKeyPoints[m.queryIdx].pt, dtype=np.int_)
curr_pt = np.array(keypoints[m.trainIdx].pt, dtype=np.int_)
curr_pt[0] += W
color = np.random.randint(0, 255, (3,))
color = (int(color[0]), int(color[1]), int(color[2]))
matches_img = cv2.line(matches_img, prev_pt, curr_pt, tuple(color), 1, cv2.LINE_AA)
matches_img = cv2.circle(matches_img, prev_pt, 2, tuple(color), -1)
matches_img = cv2.circle(matches_img, curr_pt, 2, tuple(color), -1)
plt.figure()
plt.imshow(matches_img)
plt.show()
# Find rigid matrix
if (np.size(prevPoints, 0) > 4) and (np.size(prevPoints, 0) == np.size(prevPoints, 0)):
H, inliesrs = cv2.estimateAffinePartial2D(prevPoints, currPoints, cv2.RANSAC)
# Handle downscale
if self.downscale > 1.0:
H[0, 2] *= self.downscale
H[1, 2] *= self.downscale
else:
print('Warning: not enough matching points')
# Store to next iteration
self.prevFrame = frame.copy()
self.prevKeyPoints = copy.copy(keypoints)
self.prevDescriptors = copy.copy(descriptors)
return H
def applySparseOptFlow(self, raw_frame, detections=None):
# Initialize
# t0 = time.time()
height, width, _ = raw_frame.shape
frame = cv2.cvtColor(raw_frame, cv2.COLOR_BGR2GRAY)
H = np.eye(2, 3)
# Downscale image
if self.downscale > 1.0:
# frame = cv2.GaussianBlur(frame, (3, 3), 1.5)
frame = cv2.resize(frame, (width // self.downscale, height // self.downscale))
# find the keypoints
keypoints = cv2.goodFeaturesToTrack(frame, mask=None, **self.feature_params)
# Handle first frame
if not self.initializedFirstFrame:
# Initialize data
self.prevFrame = frame.copy()
self.prevKeyPoints = copy.copy(keypoints)
# Initialization done
self.initializedFirstFrame = True
return H
# find correspondences
matchedKeypoints, status, err = cv2.calcOpticalFlowPyrLK(self.prevFrame, frame, self.prevKeyPoints, None)
# leave good correspondences only
prevPoints = []
currPoints = []
for i in range(len(status)):
if status[i]:
prevPoints.append(self.prevKeyPoints[i])
currPoints.append(matchedKeypoints[i])
prevPoints = np.array(prevPoints)
currPoints = np.array(currPoints)
# Find rigid matrix
if (np.size(prevPoints, 0) > 4) and (np.size(prevPoints, 0) == np.size(prevPoints, 0)):
H, inliesrs = cv2.estimateAffinePartial2D(prevPoints, currPoints, cv2.RANSAC)
# Handle downscale
if self.downscale > 1.0:
H[0, 2] *= self.downscale
H[1, 2] *= self.downscale
else:
print('Warning: not enough matching points')
# Store to next iteration
self.prevFrame = frame.copy()
self.prevKeyPoints = copy.copy(keypoints)
# gmc_line = str(1000 * (time.time() - t0)) + "\t" + str(H[0, 0]) + "\t" + str(H[0, 1]) + "\t" + str(
# H[0, 2]) + "\t" + str(H[1, 0]) + "\t" + str(H[1, 1]) + "\t" + str(H[1, 2]) + "\n"
# self.gmc_file.write(gmc_line)
return H
def applyFile(self, raw_frame, detections=None):
line = self.gmcFile.readline()
tokens = line.split("\t")
H = np.eye(2, 3, dtype=np.float_)
H[0, 0] = float(tokens[1])
H[0, 1] = float(tokens[2])
H[0, 2] = float(tokens[3])
H[1, 0] = float(tokens[4])
H[1, 1] = float(tokens[5])
H[1, 2] = float(tokens[6])
return H

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import numpy as np
import scipy.linalg
# Table for the 0.95 quantile of the chi-square distribution with N degrees of freedom (contains values for N=1, ..., 9)
# Taken from MATLAB/Octave's chi2inv function and used as Mahalanobis gating threshold.
chi2inv95 = {1: 3.8415, 2: 5.9915, 3: 7.8147, 4: 9.4877, 5: 11.070, 6: 12.592, 7: 14.067, 8: 15.507, 9: 16.919}
class KalmanFilterXYAH:
"""
For bytetrack
A simple Kalman filter for tracking bounding boxes in image space.
The 8-dimensional state space
x, y, a, h, vx, vy, va, vh
contains the bounding box center position (x, y), aspect ratio a, height h,
and their respective velocities.
Object motion follows a constant velocity model. The bounding box location
(x, y, a, h) is taken as direct observation of the state space (linear
observation model).
"""
def __init__(self):
ndim, dt = 4, 1.
# Create Kalman filter model matrices.
self._motion_mat = np.eye(2 * ndim, 2 * ndim)
for i in range(ndim):
self._motion_mat[i, ndim + i] = dt
self._update_mat = np.eye(ndim, 2 * ndim)
# Motion and observation uncertainty are chosen relative to the current
# state estimate. These weights control the amount of uncertainty in
# the model. This is a bit hacky.
self._std_weight_position = 1. / 20
self._std_weight_velocity = 1. / 160
def initiate(self, measurement):
"""Create track from unassociated measurement.
Parameters
----------
measurement : ndarray
Bounding box coordinates (x, y, a, h) with center position (x, y),
aspect ratio a, and height h.
Returns
-------
(ndarray, ndarray)
Returns the mean vector (8 dimensional) and covariance matrix (8x8
dimensional) of the new track. Unobserved velocities are initialized
to 0 mean.
"""
mean_pos = measurement
mean_vel = np.zeros_like(mean_pos)
mean = np.r_[mean_pos, mean_vel]
std = [
2 * self._std_weight_position * measurement[3], 2 * self._std_weight_position * measurement[3], 1e-2,
2 * self._std_weight_position * measurement[3], 10 * self._std_weight_velocity * measurement[3],
10 * self._std_weight_velocity * measurement[3], 1e-5, 10 * self._std_weight_velocity * measurement[3]]
covariance = np.diag(np.square(std))
return mean, covariance
def predict(self, mean, covariance):
"""Run Kalman filter prediction step.
Parameters
----------
mean : ndarray
The 8 dimensional mean vector of the object state at the previous
time step.
covariance : ndarray
The 8x8 dimensional covariance matrix of the object state at the
previous time step.
Returns
-------
(ndarray, ndarray)
Returns the mean vector and covariance matrix of the predicted
state. Unobserved velocities are initialized to 0 mean.
"""
std_pos = [
self._std_weight_position * mean[3], self._std_weight_position * mean[3], 1e-2,
self._std_weight_position * mean[3]]
std_vel = [
self._std_weight_velocity * mean[3], self._std_weight_velocity * mean[3], 1e-5,
self._std_weight_velocity * mean[3]]
motion_cov = np.diag(np.square(np.r_[std_pos, std_vel]))
# mean = np.dot(self._motion_mat, mean)
mean = np.dot(mean, self._motion_mat.T)
covariance = np.linalg.multi_dot((self._motion_mat, covariance, self._motion_mat.T)) + motion_cov
return mean, covariance
def project(self, mean, covariance):
"""Project state distribution to measurement space.
Parameters
----------
mean : ndarray
The state's mean vector (8 dimensional array).
covariance : ndarray
The state's covariance matrix (8x8 dimensional).
Returns
-------
(ndarray, ndarray)
Returns the projected mean and covariance matrix of the given state
estimate.
"""
std = [
self._std_weight_position * mean[3], self._std_weight_position * mean[3], 1e-1,
self._std_weight_position * mean[3]]
innovation_cov = np.diag(np.square(std))
mean = np.dot(self._update_mat, mean)
covariance = np.linalg.multi_dot((self._update_mat, covariance, self._update_mat.T))
return mean, covariance + innovation_cov
def multi_predict(self, mean, covariance):
"""Run Kalman filter prediction step (Vectorized version).
Parameters
----------
mean : ndarray
The Nx8 dimensional mean matrix of the object states at the previous
time step.
covariance : ndarray
The Nx8x8 dimensional covariance matrics of the object states at the
previous time step.
Returns
-------
(ndarray, ndarray)
Returns the mean vector and covariance matrix of the predicted
state. Unobserved velocities are initialized to 0 mean.
"""
std_pos = [
self._std_weight_position * mean[:, 3], self._std_weight_position * mean[:, 3],
1e-2 * np.ones_like(mean[:, 3]), self._std_weight_position * mean[:, 3]]
std_vel = [
self._std_weight_velocity * mean[:, 3], self._std_weight_velocity * mean[:, 3],
1e-5 * np.ones_like(mean[:, 3]), self._std_weight_velocity * mean[:, 3]]
sqr = np.square(np.r_[std_pos, std_vel]).T
motion_cov = [np.diag(sqr[i]) for i in range(len(mean))]
motion_cov = np.asarray(motion_cov)
mean = np.dot(mean, self._motion_mat.T)
left = np.dot(self._motion_mat, covariance).transpose((1, 0, 2))
covariance = np.dot(left, self._motion_mat.T) + motion_cov
return mean, covariance
def update(self, mean, covariance, measurement):
"""Run Kalman filter correction step.
Parameters
----------
mean : ndarray
The predicted state's mean vector (8 dimensional).
covariance : ndarray
The state's covariance matrix (8x8 dimensional).
measurement : ndarray
The 4 dimensional measurement vector (x, y, a, h), where (x, y)
is the center position, a the aspect ratio, and h the height of the
bounding box.
Returns
-------
(ndarray, ndarray)
Returns the measurement-corrected state distribution.
"""
projected_mean, projected_cov = self.project(mean, covariance)
chol_factor, lower = scipy.linalg.cho_factor(projected_cov, lower=True, check_finite=False)
kalman_gain = scipy.linalg.cho_solve((chol_factor, lower),
np.dot(covariance, self._update_mat.T).T,
check_finite=False).T
innovation = measurement - projected_mean
new_mean = mean + np.dot(innovation, kalman_gain.T)
new_covariance = covariance - np.linalg.multi_dot((kalman_gain, projected_cov, kalman_gain.T))
return new_mean, new_covariance
def gating_distance(self, mean, covariance, measurements, only_position=False, metric='maha'):
"""Compute gating distance between state distribution and measurements.
A suitable distance threshold can be obtained from `chi2inv95`. If
`only_position` is False, the chi-square distribution has 4 degrees of
freedom, otherwise 2.
Parameters
----------
mean : ndarray
Mean vector over the state distribution (8 dimensional).
covariance : ndarray
Covariance of the state distribution (8x8 dimensional).
measurements : ndarray
An Nx4 dimensional matrix of N measurements, each in
format (x, y, a, h) where (x, y) is the bounding box center
position, a the aspect ratio, and h the height.
only_position : Optional[bool]
If True, distance computation is done with respect to the bounding
box center position only.
Returns
-------
ndarray
Returns an array of length N, where the i-th element contains the
squared Mahalanobis distance between (mean, covariance) and
`measurements[i]`.
"""
mean, covariance = self.project(mean, covariance)
if only_position:
mean, covariance = mean[:2], covariance[:2, :2]
measurements = measurements[:, :2]
d = measurements - mean
if metric == 'gaussian':
return np.sum(d * d, axis=1)
elif metric == 'maha':
cholesky_factor = np.linalg.cholesky(covariance)
z = scipy.linalg.solve_triangular(cholesky_factor, d.T, lower=True, check_finite=False, overwrite_b=True)
return np.sum(z * z, axis=0) # square maha
else:
raise ValueError('invalid distance metric')
class KalmanFilterXYWH:
"""
For bot-sort
A simple Kalman filter for tracking bounding boxes in image space.
The 8-dimensional state space
x, y, w, h, vx, vy, vw, vh
contains the bounding box center position (x, y), width w, height h,
and their respective velocities.
Object motion follows a constant velocity model. The bounding box location
(x, y, w, h) is taken as direct observation of the state space (linear
observation model).
"""
def __init__(self):
ndim, dt = 4, 1.
# Create Kalman filter model matrices.
self._motion_mat = np.eye(2 * ndim, 2 * ndim)
for i in range(ndim):
self._motion_mat[i, ndim + i] = dt
self._update_mat = np.eye(ndim, 2 * ndim)
# Motion and observation uncertainty are chosen relative to the current
# state estimate. These weights control the amount of uncertainty in
# the model. This is a bit hacky.
self._std_weight_position = 1. / 20
self._std_weight_velocity = 1. / 160
def initiate(self, measurement):
"""Create track from unassociated measurement.
Parameters
----------
measurement : ndarray
Bounding box coordinates (x, y, w, h) with center position (x, y),
width w, and height h.
Returns
-------
(ndarray, ndarray)
Returns the mean vector (8 dimensional) and covariance matrix (8x8
dimensional) of the new track. Unobserved velocities are initialized
to 0 mean.
"""
mean_pos = measurement
mean_vel = np.zeros_like(mean_pos)
mean = np.r_[mean_pos, mean_vel]
std = [
2 * self._std_weight_position * measurement[2], 2 * self._std_weight_position * measurement[3],
2 * self._std_weight_position * measurement[2], 2 * self._std_weight_position * measurement[3],
10 * self._std_weight_velocity * measurement[2], 10 * self._std_weight_velocity * measurement[3],
10 * self._std_weight_velocity * measurement[2], 10 * self._std_weight_velocity * measurement[3]]
covariance = np.diag(np.square(std))
return mean, covariance
def predict(self, mean, covariance):
"""Run Kalman filter prediction step.
Parameters
----------
mean : ndarray
The 8 dimensional mean vector of the object state at the previous
time step.
covariance : ndarray
The 8x8 dimensional covariance matrix of the object state at the
previous time step.
Returns
-------
(ndarray, ndarray)
Returns the mean vector and covariance matrix of the predicted
state. Unobserved velocities are initialized to 0 mean.
"""
std_pos = [
self._std_weight_position * mean[2], self._std_weight_position * mean[3],
self._std_weight_position * mean[2], self._std_weight_position * mean[3]]
std_vel = [
self._std_weight_velocity * mean[2], self._std_weight_velocity * mean[3],
self._std_weight_velocity * mean[2], self._std_weight_velocity * mean[3]]
motion_cov = np.diag(np.square(np.r_[std_pos, std_vel]))
mean = np.dot(mean, self._motion_mat.T)
covariance = np.linalg.multi_dot((self._motion_mat, covariance, self._motion_mat.T)) + motion_cov
return mean, covariance
def project(self, mean, covariance):
"""Project state distribution to measurement space.
Parameters
----------
mean : ndarray
The state's mean vector (8 dimensional array).
covariance : ndarray
The state's covariance matrix (8x8 dimensional).
Returns
-------
(ndarray, ndarray)
Returns the projected mean and covariance matrix of the given state
estimate.
"""
std = [
self._std_weight_position * mean[2], self._std_weight_position * mean[3],
self._std_weight_position * mean[2], self._std_weight_position * mean[3]]
innovation_cov = np.diag(np.square(std))
mean = np.dot(self._update_mat, mean)
covariance = np.linalg.multi_dot((self._update_mat, covariance, self._update_mat.T))
return mean, covariance + innovation_cov
def multi_predict(self, mean, covariance):
"""Run Kalman filter prediction step (Vectorized version).
Parameters
----------
mean : ndarray
The Nx8 dimensional mean matrix of the object states at the previous
time step.
covariance : ndarray
The Nx8x8 dimensional covariance matrics of the object states at the
previous time step.
Returns
-------
(ndarray, ndarray)
Returns the mean vector and covariance matrix of the predicted
state. Unobserved velocities are initialized to 0 mean.
"""
std_pos = [
self._std_weight_position * mean[:, 2], self._std_weight_position * mean[:, 3],
self._std_weight_position * mean[:, 2], self._std_weight_position * mean[:, 3]]
std_vel = [
self._std_weight_velocity * mean[:, 2], self._std_weight_velocity * mean[:, 3],
self._std_weight_velocity * mean[:, 2], self._std_weight_velocity * mean[:, 3]]
sqr = np.square(np.r_[std_pos, std_vel]).T
motion_cov = [np.diag(sqr[i]) for i in range(len(mean))]
motion_cov = np.asarray(motion_cov)
mean = np.dot(mean, self._motion_mat.T)
left = np.dot(self._motion_mat, covariance).transpose((1, 0, 2))
covariance = np.dot(left, self._motion_mat.T) + motion_cov
return mean, covariance
def update(self, mean, covariance, measurement):
"""Run Kalman filter correction step.
Parameters
----------
mean : ndarray
The predicted state's mean vector (8 dimensional).
covariance : ndarray
The state's covariance matrix (8x8 dimensional).
measurement : ndarray
The 4 dimensional measurement vector (x, y, w, h), where (x, y)
is the center position, w the width, and h the height of the
bounding box.
Returns
-------
(ndarray, ndarray)
Returns the measurement-corrected state distribution.
"""
projected_mean, projected_cov = self.project(mean, covariance)
chol_factor, lower = scipy.linalg.cho_factor(projected_cov, lower=True, check_finite=False)
kalman_gain = scipy.linalg.cho_solve((chol_factor, lower),
np.dot(covariance, self._update_mat.T).T,
check_finite=False).T
innovation = measurement - projected_mean
new_mean = mean + np.dot(innovation, kalman_gain.T)
new_covariance = covariance - np.linalg.multi_dot((kalman_gain, projected_cov, kalman_gain.T))
return new_mean, new_covariance
def gating_distance(self, mean, covariance, measurements, only_position=False, metric='maha'):
"""Compute gating distance between state distribution and measurements.
A suitable distance threshold can be obtained from `chi2inv95`. If
`only_position` is False, the chi-square distribution has 4 degrees of
freedom, otherwise 2.
Parameters
----------
mean : ndarray
Mean vector over the state distribution (8 dimensional).
covariance : ndarray
Covariance of the state distribution (8x8 dimensional).
measurements : ndarray
An Nx4 dimensional matrix of N measurements, each in
format (x, y, a, h) where (x, y) is the bounding box center
position, a the aspect ratio, and h the height.
only_position : Optional[bool]
If True, distance computation is done with respect to the bounding
box center position only.
Returns
-------
ndarray
Returns an array of length N, where the i-th element contains the
squared Mahalanobis distance between (mean, covariance) and
`measurements[i]`.
"""
mean, covariance = self.project(mean, covariance)
if only_position:
mean, covariance = mean[:2], covariance[:2, :2]
measurements = measurements[:, :2]
d = measurements - mean
if metric == 'gaussian':
return np.sum(d * d, axis=1)
elif metric == 'maha':
cholesky_factor = np.linalg.cholesky(covariance)
z = scipy.linalg.solve_triangular(cholesky_factor, d.T, lower=True, check_finite=False, overwrite_b=True)
return np.sum(z * z, axis=0) # square maha
else:
raise ValueError('invalid distance metric')

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import lap
import numpy as np
import scipy
from scipy.spatial.distance import cdist
from .kalman_filter import chi2inv95
def merge_matches(m1, m2, shape):
O, P, Q = shape
m1 = np.asarray(m1)
m2 = np.asarray(m2)
M1 = scipy.sparse.coo_matrix((np.ones(len(m1)), (m1[:, 0], m1[:, 1])), shape=(O, P))
M2 = scipy.sparse.coo_matrix((np.ones(len(m2)), (m2[:, 0], m2[:, 1])), shape=(P, Q))
mask = M1 * M2
match = mask.nonzero()
match = list(zip(match[0], match[1]))
unmatched_O = tuple(set(range(O)) - {i for i, j in match})
unmatched_Q = tuple(set(range(Q)) - {j for i, j in match})
return match, unmatched_O, unmatched_Q
def _indices_to_matches(cost_matrix, indices, thresh):
matched_cost = cost_matrix[tuple(zip(*indices))]
matched_mask = (matched_cost <= thresh)
matches = indices[matched_mask]
unmatched_a = tuple(set(range(cost_matrix.shape[0])) - set(matches[:, 0]))
unmatched_b = tuple(set(range(cost_matrix.shape[1])) - set(matches[:, 1]))
return matches, unmatched_a, unmatched_b
def linear_assignment(cost_matrix, thresh):
if cost_matrix.size == 0:
return np.empty((0, 2), dtype=int), tuple(range(cost_matrix.shape[0])), tuple(range(cost_matrix.shape[1]))
matches, unmatched_a, unmatched_b = [], [], []
cost, x, y = lap.lapjv(cost_matrix, extend_cost=True, cost_limit=thresh)
matches.extend([ix, mx] for ix, mx in enumerate(x) if mx >= 0)
unmatched_a = np.where(x < 0)[0]
unmatched_b = np.where(y < 0)[0]
matches = np.asarray(matches)
return matches, unmatched_a, unmatched_b
def ious(atlbrs, btlbrs):
"""
Compute cost based on IoU
:type atlbrs: list[tlbr] | np.ndarray
:type atlbrs: list[tlbr] | np.ndarray
:rtype ious np.ndarray
"""
ious = np.zeros((len(atlbrs), len(btlbrs)), dtype=np.float32)
if ious.size == 0:
return ious
ious = bbox_ious(np.ascontiguousarray(atlbrs, dtype=np.float32), np.ascontiguousarray(btlbrs, dtype=np.float32))
return ious
def iou_distance(atracks, btracks):
"""
Compute cost based on IoU
:type atracks: list[STrack]
:type btracks: list[STrack]
:rtype cost_matrix np.ndarray
"""
if (len(atracks) > 0 and isinstance(atracks[0], np.ndarray)) \
or (len(btracks) > 0 and isinstance(btracks[0], np.ndarray)):
atlbrs = atracks
btlbrs = btracks
else:
atlbrs = [track.tlbr for track in atracks]
btlbrs = [track.tlbr for track in btracks]
_ious = ious(atlbrs, btlbrs)
return 1 - _ious # cost matrix
def v_iou_distance(atracks, btracks):
"""
Compute cost based on IoU
:type atracks: list[STrack]
:type btracks: list[STrack]
:rtype cost_matrix np.ndarray
"""
if (len(atracks) > 0 and isinstance(atracks[0], np.ndarray)) \
or (len(btracks) > 0 and isinstance(btracks[0], np.ndarray)):
atlbrs = atracks
btlbrs = btracks
else:
atlbrs = [track.tlwh_to_tlbr(track.pred_bbox) for track in atracks]
btlbrs = [track.tlwh_to_tlbr(track.pred_bbox) for track in btracks]
_ious = ious(atlbrs, btlbrs)
return 1 - _ious # cost matrix
def embedding_distance(tracks, detections, metric='cosine'):
"""
:param tracks: list[STrack]
:param detections: list[BaseTrack]
:param metric:
:return: cost_matrix np.ndarray
"""
cost_matrix = np.zeros((len(tracks), len(detections)), dtype=np.float32)
if cost_matrix.size == 0:
return cost_matrix
det_features = np.asarray([track.curr_feat for track in detections], dtype=np.float32)
# for i, track in enumerate(tracks):
# cost_matrix[i, :] = np.maximum(0.0, cdist(track.smooth_feat.reshape(1,-1), det_features, metric))
track_features = np.asarray([track.smooth_feat for track in tracks], dtype=np.float32)
cost_matrix = np.maximum(0.0, cdist(track_features, det_features, metric)) # Nomalized features
return cost_matrix
def gate_cost_matrix(kf, cost_matrix, tracks, detections, only_position=False):
if cost_matrix.size == 0:
return cost_matrix
gating_dim = 2 if only_position else 4
gating_threshold = chi2inv95[gating_dim]
measurements = np.asarray([det.to_xyah() for det in detections])
for row, track in enumerate(tracks):
gating_distance = kf.gating_distance(track.mean, track.covariance, measurements, only_position)
cost_matrix[row, gating_distance > gating_threshold] = np.inf
return cost_matrix
def fuse_motion(kf, cost_matrix, tracks, detections, only_position=False, lambda_=0.98):
if cost_matrix.size == 0:
return cost_matrix
gating_dim = 2 if only_position else 4
gating_threshold = chi2inv95[gating_dim]
measurements = np.asarray([det.to_xyah() for det in detections])
for row, track in enumerate(tracks):
gating_distance = kf.gating_distance(track.mean, track.covariance, measurements, only_position, metric='maha')
cost_matrix[row, gating_distance > gating_threshold] = np.inf
cost_matrix[row] = lambda_ * cost_matrix[row] + (1 - lambda_) * gating_distance
return cost_matrix
def fuse_iou(cost_matrix, tracks, detections):
if cost_matrix.size == 0:
return cost_matrix
reid_sim = 1 - cost_matrix
iou_dist = iou_distance(tracks, detections)
iou_sim = 1 - iou_dist
fuse_sim = reid_sim * (1 + iou_sim) / 2
# det_scores = np.array([det.score for det in detections])
# det_scores = np.expand_dims(det_scores, axis=0).repeat(cost_matrix.shape[0], axis=0)
return 1 - fuse_sim # fuse cost
def fuse_score(cost_matrix, detections):
if cost_matrix.size == 0:
return cost_matrix
iou_sim = 1 - cost_matrix
det_scores = np.array([det.score for det in detections])
det_scores = np.expand_dims(det_scores, axis=0).repeat(cost_matrix.shape[0], axis=0)
fuse_sim = iou_sim * det_scores
return 1 - fuse_sim # fuse_cost
def bbox_ious(box1, box2, eps=1e-7):
"""Boxes are x1y1x2y2
box1: np.array of shape(nx4)
box2: np.array of shape(mx4)
returns: np.array of shape(nxm)
"""
# Get the coordinates of bounding boxes
b1_x1, b1_y1, b1_x2, b1_y2 = box1.T
b2_x1, b2_y1, b2_x2, b2_y2 = box2.T
# Intersection area
inter_area = (np.minimum(b1_x2[:, None], b2_x2) - np.maximum(b1_x1[:, None], b2_x1)).clip(0) * \
(np.minimum(b1_y2[:, None], b2_y2) - np.maximum(b1_y1[:, None], b2_y1)).clip(0)
# box2 area
box1_area = (b1_x2 - b1_x1) * (b1_y2 - b1_y1)
box2_area = (b2_x2 - b2_x1) * (b2_y2 - b2_y1)
return inter_area / (box2_area + box1_area[:, None] - inter_area + eps)