115 lines
2.8 KiB
Python
115 lines
2.8 KiB
Python
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import cv2
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import numpy as np
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import scipy.ndimage as ndi
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import matplotlib.pyplot as plt
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# customized imshow function
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def imshow(img, cap=None):
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if np.amax(img) > 255:
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img = img / (np.amax(img)) * 255
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img.astype(np.uint8)
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fig = plt.figure(figsize=(4, 4))
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if cap is not None:
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plt.title(cap)
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plt.imshow(img, cmap="gray")
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plt.axis("off")
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plt.show()
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def apply(img, ker):
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return np.abs(np.fft.ifft2(np.fft.fftshift(np.fft.fft2(img)) * ker).real)
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################################################################
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# Ideal LowPass Filter kernel
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def ilpf(m, n, r):
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a = np.tile(np.arange(-n / 2, n / 2), (m, 1))
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b = np.tile(np.arange(-m / 2, m / 2), (n, 1)).T
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return (a * a + b * b < r * r).astype(np.uint8)
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# Print ILPF Result
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def apply_ilpf(img, r):
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row, col = img.shape
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imshow(img(*ilpf(row, col, r)), 'Ideal LowPass Filter\nwith r = ' + str(r))
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img = cv2.imread("C:/Users/NGPD/Desktop/2.jpg", cv2.IMREAD_GRAYSCALE)
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imshow(img, 'Loaded Image')
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apply_ilpf(img, 5)
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apply_ilpf(img, 15)
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apply_ilpf(img, 30)
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apply_ilpf(img, 80)
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################################################################
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# Butterworth LPF kernel
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def blpf(m, n, N, r):
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a = np.tile(np.arange(-n / 2, n / 2), (m, 1))
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b = np.tile(np.arange(-m / 2, m / 2), (n, 1)).T
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return (1 / (1 + ((a * a + b * b) / (r * r))**N))
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# Print BLPF Result
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def apply_blpf(img, N, r):
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row, col = img.shape
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imshow(img(*blpf(row, col, N, r)),
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'Butterworth LowPass Filter\nwith r = ' + str(r) + ' and n = ' + str(N))
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img = cv2.imread("C:/Users/NGPD/Desktop/2.jpg", cv2.IMREAD_GRAYSCALE)
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imshow(img, 'Loaded Image')
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n = 2
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apply_blpf(img, n, 5)
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apply_blpf(img, n, 15)
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apply_blpf(img, n, 30)
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apply_blpf(img, n, 80)
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################################################################
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# Gaussian LPF kernel
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def glpf(m, n, r):
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a = np.tile(np.arange(-n / 2, n / 2), (m, 1))
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b = np.tile(np.arange(-m / 2, m / 2), (n, 1)).T
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return np.exp(-(a * a + b * b) / (2 * r * r))
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# Print GLPF Result
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def apply_glpf(img, r):
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row, col = img.shape
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imshow(img(*glpf(row, col, r)), 'Gaussian LowPass Filter\nwith r = ' + str(r))
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img = cv2.imread("C:/Users/NGPD/Desktop/2.jpg", cv2.IMREAD_GRAYSCALE)
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imshow(img, 'Loaded Image')
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apply_glpf(img, 5)
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apply_glpf(img, 15)
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apply_glpf(img, 30)
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apply_glpf(img, 80)
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################################################################
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img = cv2.imread("C:/Users/NGPD/Desktop/2.jpg", cv2.IMREAD_GRAYSCALE)
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m, n = img.shape
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a = np.tile(np.arange(-n / 2, n / 2), (m, 1))
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b = np.tile(np.arange(-m / 2, m / 2), (n, 1)).T
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lap = img(*-(a * a + b * b))
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if np.amax(lap) > 255:
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lap = lap / (np.amax(lap)) * 255
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imshow(img, 'Loaded Image')
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imshow(lap, 'Laplacian Filter')
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imshow(img - lap, 'g(x, y)')
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