image_sample.py 文件源码

def test_sample(self):
        import numpy as np
        h, w = 3, 4
        def np_sample(img, coords):
            # a reference implementation
            coords = np.maximum(coords, 0)
            coords = np.minimum(coords,
                                np.array([img.shape[1]-1, img.shape[2]-1]))
            xs = coords[:,:,:,1].reshape((img.shape[0], -1))
            ys = coords[:,:,:,0].reshape((img.shape[0], -1))

            ret = np.zeros((img.shape[0], coords.shape[1], coords.shape[2],
                            img.shape[3]), dtype='float32')
            for k in range(img.shape[0]):
                xss, yss = xs[k], ys[k]
                ret[k,:,:,:] = img[k,yss,xss,:].reshape((coords.shape[1],
                                                         coords.shape[2], 3))
            return ret

        bimg = np.random.rand(2, h, w, 3).astype('float32')

        #mat = np.array([
            #[[[1,1], [1.2,1.2]], [[-1, -1], [2.5, 2.5]]],
            #[[[1,1], [1.2,1.2]], [[-1, -1], [2.5, 2.5]]]
        #], dtype='float32')  #2x2x2x2
        mat = (np.random.rand(2, 5, 5, 2) - 0.2) * np.array([h + 3, w + 3])
        true_res = np_sample(bimg, np.floor(mat + 0.5).astype('int32'))

        inp, mapping = self.make_variable(bimg, mat)
        output = sample(inp, tf.cast(tf.floor(mapping+0.5), tf.int32))
        res = self.run_variable(output)

        self.assertTrue((res == true_res).all())