def test_cauchy_noise():
np.random.seed(2012)
for shape in [10, 10], [100, 1000], [500, 50]:
val = np.random.normal(0, 10)
x = np.full(shape, val)
noisy = cauchy_noise(x, np.ones(shape[1]))
def example_filter():
# create the filter
pf = ParticleFilter(
prior_fn=prior_fn,
observe_fn=blob,
n_particles=100,
dynamics_fn=velocity,
noise_fn=lambda x: cauchy_noise(x, sigmas=[0.05, 0.05, 0.01, 0.005, 0.005]),
weight_fn=lambda x, y: squared_error(x, y, sigma=2),
resample_proportion=0.2,
column_names=columns,
)
# np.random.seed(2018)
# start in centre, random radius
s = np.random.uniform(2, 8)
# random movement direction
dx = np.random.uniform(-0.25, 0.25)
dy = np.random.uniform(-0.25, 0.25)
# appear at centre
x = img_size // 2
y = img_size // 2
scale_factor = 20
# create window
cv2.namedWindow("samples", cv2.WINDOW_NORMAL)
cv2.resizeWindow("samples", scale_factor * img_size, scale_factor * img_size)
for i in range(1000):
# generate the actual image
low_res_img = blob(np.array([[x, y, s]]))
pf.update(low_res_img)
# resize for drawing onto
img = cv2.resize(
np.squeeze(low_res_img), (0, 0), fx=scale_factor, fy=scale_factor
)
cv2.putText(
img,
"ESC to exit",
(50, 50),
cv2.FONT_HERSHEY_SIMPLEX,
1,
(255, 255, 255),
2,
cv2.LINE_AA,
)
color = cv2.cvtColor(img.astype(np.float32), cv2.COLOR_GRAY2RGB)
x_hat, y_hat, s_hat, dx_hat, dy_hat = pf.mean_state
# draw individual particles
for particle in pf.original_particles:
xa, ya, sa, _, _ = particle
sa = np.clip(sa, 1, 100)
cv2.circle(
color,
(int(ya * scale_factor), int(xa * scale_factor)),
int(sa * scale_factor),
(1, 0, 0),
1,
)
# x,y exchange because of ordering between skimage and opencv
cv2.circle(
color,
(int(y_hat * scale_factor), int(x_hat * scale_factor)),
int(s_hat * scale_factor),
(0, 1, 0),
1,
lineType=cv2.LINE_AA,
)
cv2.line(
color,
(int(y_hat * scale_factor), int(x_hat * scale_factor)),
(
int(y_hat * scale_factor + 5 * dy_hat * scale_factor),
int(x_hat * scale_factor + 5 * dx_hat * scale_factor),
),
(0, 0, 1),
lineType=cv2.LINE_AA,
)
cv2.imshow("samples", color)
result = cv2.waitKey(20)
# break on escape
if result == 27:
break
x += dx
y += dy
cv2.destroyAllWindows()