Python Q1.dft2D 예제들

예제 #1

def generateImg():
    f = np.zeros([512, 512], dtype=np.float)
    f[225:285, 250:260] = 1
    return f


if __name__ == '__main__':
    plt.figure()
    #产生图像
    f = generateImg()
    plt.subplot(2, 2, 1)
    plt.imshow(f, 'gray')

    #fft变换
    f_fft = Q1.dft2D(f)
    plt.subplot(2, 2, 2)
    plt.imshow(np.abs(f_fft), 'gray')

    #中心化
    F = np.fft.fftshift(f_fft)
    plt.subplot(2, 2, 3)
    plt.imshow(np.abs(F), 'gray')

    #对数变换
    s = np.log(1 + np.abs(F))
    plt.subplot(2, 2, 4)
    plt.imshow(s, 'gray')

    plt.show()

예제 #2

'''
@author: shibaorong
@license: (C) Copyright 2019, Node Supply Chain Manager Corporation Limited.
@contact: [email protected]
@software: pycharm
@file: Q3.py
@time: 2019/10/12 16:57
@desc:
'''
import Q1
import Q2
import cv2
import matplotlib.pyplot as plt
import numpy as np


def normalization(f):
    return f / 255.0


if __name__ == '__main__':

    f = cv2.imread('rose512.tif', 0)
    f = normalization(f)
    F = Q1.dft2D(f)
    g = Q2.idft2D(F)
    d = f - g
    fimg = np.abs(d)
    plt.imshow(fimg, 'gray')
    plt.show()

예제 #3

@license: (C) Copyright 2019, Node Supply Chain Manager Corporation Limited.
@contact: [email protected]
@software: pycharm
@file: Q2.py
@time: 2019/10/12 16:17
@desc:
'''
import Q1
import numpy as np
import cv2
import matplotlib.pyplot as plt

def idft2D(F):

    F_shape=F.shape
    F=F.conj()
    F=np.fft.fft(F,axis=-2)
    F = np.fft.fft(F, axis=-1)
    F/=F_shape[0]*F_shape[1]
    F=F.conj()
    return F

if __name__=='__main__':
    F = cv2.imread('rose512.tif', 0)
    #plt.imshow(F/255.0, 'gray')
    F=Q1.dft2D(F)
    C=idft2D(F)
    fimg = np.abs(C)
    plt.imshow(fimg, 'gray')
    plt.show()