46 lines
991 B
Python
46 lines
991 B
Python
import numpy as np
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from matplotlib import pyplot as plt
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def draw_line(rho, theta, h, w):
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"""
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Example usage:
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plt.imshow(I)
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draw_line(rho1, theta1, h, w)
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draw_line(rho2, theta2, h, w)
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draw_line(rho3, theta3, h, w)
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plt.show()
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"rho" and "theta": Parameters for the line which will be drawn.
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"h", "w": Height and width of an image.
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"""
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c = np.cos(theta)
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s = np.sin(theta)
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xs = []
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ys = []
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if s != 0:
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y = int(rho / s)
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if 0 <= y < h:
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xs.append(0)
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ys.append(y)
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y = int((rho - w * c) / s)
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if 0 <= y < h:
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xs.append(w - 1)
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ys.append(y)
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if c != 0:
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x = int(rho / c)
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if 0 <= x < w:
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xs.append(x)
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ys.append(0)
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x = int((rho - h * s) / c)
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if 0 <= x < w:
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xs.append(x)
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ys.append(h - 1)
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plt.plot(xs[:2], ys[:2], 'r', linewidth=.7)
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