def semiLine(im, x0, theta, w, l, H=200, dohalf=True):
""" Plot half-line into image
Args:
im (array)
x0 (array): starting point of semi-line
theta (float): angle in radians
w (float): width
l (float): length of line segment
H (float): intensity of line segment
dohalf (bool): add smoothing?
>>> im=semiLine(np.zeros( (160,240)), [60,40], theta=np.deg2rad(20), w=10, l=60)
>>> plt.imshow(im)
"""
thetar = -theta
xx0, yy0 = np.meshgrid(np.arange(im.shape[1]) - x0[0], np.arange(im.shape[0]) - x0[1])
xx0 = xx0.astype(np.float32)
yy0 = yy0.astype(np.float32)
xxr = math.cos(thetar) * xx0 - math.sin(thetar) * yy0
yyr = math.sin(thetar) * xx0 + math.cos(thetar) * yy0
yyr = pgeometry.signedmin(yyr, w / 2.)
data = H * np.cos((np.pi / w) * yyr)
if dohalf:
data *= (pgeometry.smoothstep(xxr, 0, 10))
im += data
return im
def lineSegment(im, x0, x1=None, theta=None, w=2, l=12, H=200, ml=0):
""" Plot half-line into image
>>> lineSegment(np.zeros( (160,240)), [60,40], [70,40], w=10, l=60)
>>> lineSegment(np.zeros( (160,240)), [60,40], theta=np.deg2rad(20), w=10, l=60)
"""
x0 = np.array(x0).flatten()
if x1 is None:
thetar = -theta
dx = l
else:
x1 = np.array(x1).flatten()
theta = x0 - x1
theta = np.arctan2(theta[1], theta[0]) + np.pi
thetar = -theta
dx = np.linalg.norm(x0 - x1)
xx0, yy0 = np.meshgrid(np.arange(im.shape[1]) - x0[0], np.arange(im.shape[0]) - x0[1])
xx0 = xx0.astype(np.float32)
yy0 = yy0.astype(np.float32)
xxr = math.cos(thetar) * xx0 - math.sin(thetar) * yy0
yyr = math.sin(thetar) * xx0 + math.cos(thetar) * yy0
yyr = pgeometry.signedmin(yyr, w / 2.)
data = H * np.cos((np.pi / w) * yyr) * (pgeometry.smoothstep(xxr, ml, 4)) * (1 - pgeometry.smoothstep(xxr, dx, 4))
im += data
return im