test_orientation_filter.py 文件源码

def test_bowtie(self):
        # Test the bowtie filter with sine waves
        wDeg = 3
        nPix = 257
        sf = 1
        orientation = 0

        x = y = np.linspace(-wDeg // 2, wDeg // 2, nPix + 1)
        u, v = np.meshgrid(x, y)

        ramp = np.sin(orientation * np.pi / 180) * u
        ramp -= np.cos(orientation * np.pi / 180) * v
        img = np.sin(2 * np.pi * sf * ramp)
        fimg = fft2(img)

        orientation_widths = [1, 10, 20, 40, 80, 100]
        for x in orientation_widths:
            filt = OrientationFilter('bowtie', 90, x, nPix, .2, nPix + 1,
                                     'triangle')
            filt = filt.filter
            filt = 1 - filt
            filt = fftshift(filt)
            out = ifft2(fimg * filt).real.astype(int)

            self.assertEqual(np.sum(out), 0)