版权声明:本文为博主原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接和本声明。
理想高通滤波
式中的 表达为:
Python语言实现如下:
def high_pass_kernel(img,cut_off):
assert img.ndim == 2
r,c = img.shape[1],img.shape[0]
u = np.arange(r)
v = np.arange(c)
u, v = np.meshgrid(u, v)
low_pass = np.sqrt( (u-r/2)**2 + (v-c/2)**2 )
low_pass[low_pass <= cut_off] = 1
low_pass[low_pass > cut_off] = 0
return low_pass
def high_pass(src,D0=5):
assert src.ndim == 2
kernel = high_pass_kernel(src,D0)
gray = np.float64(src)
gray_fft = np.fft.fft2(gray)
gray_fftshift = np.fft.fftshift(gray_fft)
dst = np.zeros_like(gray_fftshift)
dst_filtered = kernel * gray_fftshift
dst_ifftshift = np.fft.ifftshift(dst_filtered)
dst_ifft = np.fft.ifft2(dst_ifftshift)
dst = np.abs(np.real(dst_ifft))
dst = np.clip(dst,0,255)
return np.uint8(dst)
程序运行结果如下: