ImageprocessingHW2/problem1.py at master · 15024287710Jackson/ImageprocessingHW2 · GitHub

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import numpy as np
from matplotlib import pyplot as plt
from skimage import data, img_as_float


def original_code(Original_image):
    sigmax,sigmay=20,20
    nrows,ncols=Original_image.shape
    ftimage = np.fft.fft2(Original_image)
    fft_shift_image = np.fft.fftshift(ftimage)
    cy,cx=nrows/2,ncols/2
    x=np.linspace(0,nrows,nrows)
    y=np.linspace(0,ncols,ncols)
    X,Y =np.meshgrid(x,y)
    gmask=np.exp( -(((X-cx)/sigmax)**2+((Y-cy)/sigmay)**2))
    fft_fifltered=fft_shift_image*gmask
    fiflter_image=np.abs(np.fft.ifft2(np.fft.ifftshift(fft_fifltered)))
    return fiflter_image

def paddingcode(Original_image):
    sigmax, sigmay = 40, 40
    nrows, ncols = Original_image.shape
    padding_image=np.pad(Original_image,(int(nrows/2),int(ncols/2)),'reflect')
    ftimage = np.fft.fft2(padding_image)
    fft_shift_image = np.fft.fftshift(ftimage)
    padd_rows, padd_ncols = padding_image.shape
    cy,cx=padd_rows/2,padd_ncols/2
    x=np.linspace(0,padd_rows,padd_rows)
    y=np.linspace(0,padd_ncols,padd_ncols)
    X,Y =np.meshgrid(x,y)
    gmask=np.exp( -(((X-cx)/sigmax)**2+((Y-cy)/sigmay)**2))
    fft_fifltered=fft_shift_image*gmask
    fiflter_image=np.abs(np.fft.ifft2(np.fft.ifftshift(fft_fifltered)))
    final_fiflter_image = fiflter_image[int(nrows/2):int(3*nrows/2),int(ncols/2):int(3*ncols/2)]
    return padding_image,fiflter_image,final_fiflter_image

if __name__ == '__main__':
    Original_image = img_as_float(data.camera())
    print('Original_image',type(Original_image), Original_image.dtype, Original_image.shape)
    plt.figure(1)
    plt.title('Original image')
    plt.imshow(Original_image, cmap='gray', interpolation='nearest');
    fiflter_image=original_code(Original_image)
    print('fiflter_image',type(fiflter_image), fiflter_image.dtype, fiflter_image.shape)
    plt.figure(2)
    plt.title('Image generated by the original code')
    plt.imshow(fiflter_image, cmap='gray');
    padding_image,fiflter_image,final_fiflter_image = paddingcode(Original_image)
    print('padding_image',type(padding_image), padding_image.dtype, padding_image.shape)
    plt.figure(3)
    plt.title('Padded image (2M×2N)')
    plt.imshow(padding_image, cmap='gray');
    print('fiflter_image',type(fiflter_image), fiflter_image.dtype, fiflter_image.shape)
    plt.figure(4)
    plt.title(' Filtered padded image (2M×2N)')
    plt.imshow(fiflter_image, cmap='gray');
    plt.figure(5)
    print('fiflter_image', type(final_fiflter_image), final_fiflter_image.dtype, final_fiflter_image.shape)
    plt.title('Image with no wraparound error (M×N)')
    plt.imshow(final_fiflter_image, cmap='gray');
    plt.show()