60 lines
1.6 KiB
Python
60 lines
1.6 KiB
Python
import cv2 as cv
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import matplotlib.pyplot as plt
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import numpy as np
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plt.rcParams["font.family"] = ["SimSun"]
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src = cv.imread(r"img\peppers.bmp", cv.IMREAD_GRAYSCALE)
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dft0 = cv.dft(np.float32(src), flags=cv.DFT_COMPLEX_OUTPUT) # type: ignore
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row, col = src.shape[:2]
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src1 = np.zeros((row, col), dtype=np.float32)
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for i in range(row):
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for j in range(col):
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src1[i, j] = np.float32(src[i, j]) * ((-1) ** (i + j))
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dft1 = cv.dft(src1, flags=cv.DFT_COMPLEX_OUTPUT)
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magnitude0 = cv.magnitude(dft1[:, :, 0], dft1[:, :, 1])
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magnitude1 = 20 * np.log(1 + magnitude0) # type: ignore
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phase = cv.phase(dft1[:, :, 0], dft1[:, :, 1])
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idft0 = cv.idft(dft0)
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idft1 = cv.magnitude(idft0[:, :, 0], idft0[:, :, 1])
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fft2 = np.fft.fft2(src)
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fftshift = np.fft.fftshift(fft2)
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abs0 = np.abs(fftshift)
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abs1 = 20 * np.log(1 + abs0)
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angle = np.angle(fftshift)
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ifft20 = np.fft.ifft2(fftshift)
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ifft21 = np.abs(ifft20)
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plt.figure()
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plt.subplot(2, 4, (1, 5))
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plt.title("输入图像")
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plt.imshow(src, cmap="gray")
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plt.axis("off")
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plt.subplot(2, 4, 2)
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plt.title("幅值谱（OpenCV）")
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plt.imshow(magnitude1, cmap="gray")
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plt.axis("off")
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plt.subplot(2, 4, 3)
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plt.title("相位谱（OpenCV）")
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plt.imshow(phase, cmap="gray")
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plt.axis("off")
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plt.subplot(2, 4, 4)
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plt.title("重构图像（OpenCV）")
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plt.imshow(idft1, cmap="gray")
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plt.axis("off")
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plt.subplot(2, 4, 6)
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plt.title("幅值谱（NumPy）")
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plt.imshow(abs1, cmap="gray")
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plt.axis("off")
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plt.subplot(2, 4, 7)
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plt.title("相位谱（NumPy）")
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plt.imshow(angle, cmap="gray")
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plt.axis("off")
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plt.subplot(2, 4, 8)
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plt.title("重构图像（NumPy）")
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plt.imshow(ifft21, cmap="gray")
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plt.axis("off")
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plt.tight_layout()
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plt.show()
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