def get_circle(size):
circle = np.zeros((size, size))
radius = size // 2
center = (radius, radius)
for y in range(0, size):
for x in range(0, size):
if (x - radius)**2 + (y - radius)**2 < radius**2:
circle[y, x] = 1
for i in np.arange(0, 360, .1):
x, y = calculatePositionSafe(i, size, center)
circle[y, x] = 1
return circle
def radon(oryg_image, image, angle, n_detectors, sinogram_arr, emission_angle, diameter):
angle_between_rays = emission_angle / (n_detectors - 1)
angles = np.arange(-emission_angle/2, emission_angle/2 + emission_angle/n_detectors , angle_between_rays)
radius = diameter // 2 - 1
center = (radius, radius)
start = calculatePositionSafe(angle, diameter, center)
x = 0
for i in angles:
if parallel_rays_mode:
start, end = parallel_ray(start, angle, i*2, diameter, center)
else:
end = inclined_ray(angle, i*2, diameter, center)
line_sum = draw_line(oryg_image, image, start_point=start, end_point=end)
sinogram_arr[angle, x] = line_sum
x += 1
def inverse_radon(image, sinogram, diameter, angle, emission_angle, n_detectors):
angle_between_rays = emission_angle / (n_detectors - 1)
angles = np.arange(-emission_angle / 2, emission_angle / 2 + emission_angle / n_detectors, angle_between_rays)
radius = diameter // 2 - 1
center = (radius, radius)
start = calculatePositionSafe(angle, diameter, center)
x = 0
for i in angles:
if parallel_rays_mode:
start, end = parallel_ray(start, angle, i*2, diameter, center)
else:
end = inclined_ray(angle, i*2, diameter, center)
reconstruct_line(sinogram_value=sinogram[angle, x], reconstruction_image=image, start_point=start, end_point=end)
x+=1
def inclined_ray(main_angle, minor_angle, diameter, center):
end_point = calculatePositionSafe(main_angle + minor_angle, diameter,
center)
return (diameter - end_point[0], diameter - end_point[1])
def parallel_ray(main_point_start, main_angle, minor_angle, diameter, center):
start = calculatePositionSafe(main_angle + minor_angle, diameter, center)
end = calculatePositionSafe(main_angle - 180 + (-1) * minor_angle,
diameter, center)
return start, end