def hough_circle_detector(
image: ImageImpl,
threshold: int = 0.4,
min_radius: int = 10,
max_radius: int = 40,
steps: int = 100,
high_threshold: float = 75,
low_threshold: float = 35,
) -> ImageImpl:
img = Image.fromarray(image.to_rgb().get_array())
img = img.resize((300, 200), Image.ANTIALIAS)
image = ImageImpl(np.array(img))
border_image = border_detection.canny_detection(image, 3, 10,
high_threshold,
low_threshold, 10)
edge_pixels = np.where(
border_image.get_array()[..., 0] == constants.MAX_PIXEL_VALUE)
rmin = min_radius
rmax = max_radius
points = []
for r in range(rmin, rmax + 1):
for t in range(steps):
points.append((r, int(r * cos(2 * pi * t / steps)),
int(r * sin(2 * pi * t / steps))))
coordinates = list(zip(edge_pixels[0], edge_pixels[1]))
acc = defaultdict(int)
for y, x in coordinates:
for r, dx, dy in points:
a = x - dx
b = y - dy
acc[(a, b, r)] += 1
circles = []
iterator = sorted(acc.items(), key=lambda i: -i[1])
for k, v in iterator:
x, y, r = k
if v / steps >= threshold and all(
(x - xc)**2 + (y - yc)**2 > rc**2 for xc, yc, rc in circles):
print(v / steps, x, y, r)
circles.append((x, y, r))
result = image.to_rgb()
img = Image.fromarray(result.get_array())
draw_result = ImageDraw.Draw(img)
for x, y, r in circles:
draw_result.ellipse((x - r, y - r, x + r, y + r),
outline=(255, 0, 0, 0))
result = ImageImpl(np.array(img))
return result
def susan_detection(a_img: ImageImpl, threshold: int, low_filter: float,
high_filter: float, color: int) -> ImageImpl:
"""
:param a_img:
:param kernel_size:
:param threshold:
:return:
"""
# circ_kernel = circular_kernel(7)
circ_kernel = np.array([
[0, 0, 1, 1, 1, 0, 0],
[0, 1, 1, 1, 1, 1, 0],
[1, 1, 1, 1, 1, 1, 1],
[1, 1, 1, 1, 1, 1, 1],
[1, 1, 1, 1, 1, 1, 1],
[0, 1, 1, 1, 1, 1, 0],
[0, 0, 1, 1, 1, 0, 0],
])
original = ImageImpl(a_img.get_array())
a_img.apply_filter(
circ_kernel,
lambda m: _calculate_c_for_susan(m, circ_kernel, threshold))
# a_img.array = np.uint8(a_img.array > 0.75)
border_img = np.uint8(a_img.array > low_filter)
b_img = border_img - np.uint8(a_img.array > high_filter)
border_img = np.zeros((border_img.shape[0], border_img.shape[1], 3))
# because we only have 3 channels
color = color % 3
border_img[:, :, color] = b_img[:, :, 0]
border_img = ImageImpl(border_img)
result = border_img.mul_scalar(255)
original = original.to_rgb()
# result.add_image(original)
return original.add(result)
def hough_line_detector(
image: ImageImpl,
epsilon: float,
threshold: int,
theta_step: int = 7,
rho_step: int = 5,
) -> ImageImpl:
border_image = border_detection.canny_detection(image, 3, 10, 10)
D = max(image.height, image.width)
max_rho = np.sqrt(2) * D
rho_range = np.arange(-max_rho, max_rho, rho_step)
theta_range = np.deg2rad(np.arange(-90, 90, theta_step))
theta_cos = np.cos(theta_range)
theta_sin = np.sin(theta_range)
edge_pixels = np.where(
border_image.get_array()[..., 0] == constants.MAX_PIXEL_VALUE)
coordinates = list(zip(edge_pixels[0], edge_pixels[1]))
accumulator = np.zeros((len(theta_range), len(rho_range)))
for p in range(len(coordinates)):
for theta_idx in range(len(theta_range)):
for rho_idx in range(len(rho_range)):
# Veo si cumple la ecuacion de la recta
if (abs(rho_range[rho_idx] -
coordinates[p][1] * theta_cos[theta_idx] -
coordinates[p][0] * theta_sin[theta_idx]) < epsilon):
accumulator[theta_idx, rho_idx] += 1
result = image.to_rgb()
for rho_idx in range(len(rho_range)):
for theta_idx in range(len(theta_range)):
if accumulator[theta_idx, rho_idx] >= threshold:
result = draw_lines(result, rho_range[rho_idx],
theta_range[theta_idx])
return result
