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Diffstat (limited to 'tensorflow/contrib/image/python/kernel_tests/dense_image_warp_test.py')
| -rw-r--r-- | tensorflow/contrib/image/python/kernel_tests/dense_image_warp_test.py | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/tensorflow/contrib/image/python/kernel_tests/dense_image_warp_test.py b/tensorflow/contrib/image/python/kernel_tests/dense_image_warp_test.py new file mode 100644 index 0000000000..a58b6a247e --- /dev/null +++ b/tensorflow/contrib/image/python/kernel_tests/dense_image_warp_test.py @@ -0,0 +1,267 @@ +# Copyright 2018 The TensorFlow Authors. All Rights Reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# ============================================================================== +"""Tests for dense_image_warp.""" +from __future__ import absolute_import +from __future__ import division +from __future__ import print_function + +import math +import numpy as np + +from tensorflow.contrib.image.python.ops import dense_image_warp + +from tensorflow.python.framework import constant_op +from tensorflow.python.framework import dtypes + +from tensorflow.python.framework import test_util +from tensorflow.python.ops import array_ops +from tensorflow.python.ops import gradients +from tensorflow.python.ops import math_ops +from tensorflow.python.ops import random_ops +from tensorflow.python.ops import variables +from tensorflow.python.platform import googletest + +from tensorflow.python.training import adam + + +class DenseImageWarpTest(test_util.TensorFlowTestCase): + + def setUp(self): + np.random.seed(0) + + def test_interpolate_small_grid_ij(self): + grid = constant_op.constant( + [[0., 1., 2.], [3., 4., 5.], [6., 7., 8.]], shape=[1, 3, 3, 1]) + query_points = constant_op.constant( + [[0., 0.], [1., 0.], [2., 0.5], [1.5, 1.5]], shape=[1, 4, 2]) + expected_results = np.reshape(np.array([0., 3., 6.5, 6.]), [1, 4, 1]) + + interp = dense_image_warp._interpolate_bilinear(grid, query_points) + + with self.test_session() as sess: + predicted = sess.run(interp) + self.assertAllClose(expected_results, predicted) + + def test_interpolate_small_grid_xy(self): + grid = constant_op.constant( + [[0., 1., 2.], [3., 4., 5.], [6., 7., 8.]], shape=[1, 3, 3, 1]) + query_points = constant_op.constant( + [[0., 0.], [0., 1.], [0.5, 2.0], [1.5, 1.5]], shape=[1, 4, 2]) + expected_results = np.reshape(np.array([0., 3., 6.5, 6.]), [1, 4, 1]) + + interp = dense_image_warp._interpolate_bilinear( + grid, query_points, indexing='xy') + + with self.test_session() as sess: + predicted = sess.run(interp) + self.assertAllClose(expected_results, predicted) + + def test_interpolate_small_grid_batched(self): + grid = constant_op.constant( + [[[0., 1.], [3., 4.]], [[5., 6.], [7., 8.]]], shape=[2, 2, 2, 1]) + query_points = constant_op.constant([[[0., 0.], [1., 0.], [0.5, 0.5]], + [[0.5, 0.], [1., 0.], [1., 1.]]]) + expected_results = np.reshape( + np.array([[0., 3., 2.], [6., 7., 8.]]), [2, 3, 1]) + + interp = dense_image_warp._interpolate_bilinear(grid, query_points) + + with self.test_session() as sess: + predicted = sess.run(interp) + self.assertAllClose(expected_results, predicted) + + def get_image_and_flow_placeholders(self, shape, image_type, flow_type): + batch_size, height, width, numchannels = shape + image_shape = [batch_size, height, width, numchannels] + flow_shape = [batch_size, height, width, 2] + + tf_type = { + 'float16': dtypes.half, + 'float32': dtypes.float32, + 'float64': dtypes.float64 + } + + image = array_ops.placeholder(dtype=tf_type[image_type], shape=image_shape) + + flows = array_ops.placeholder(dtype=tf_type[flow_type], shape=flow_shape) + return image, flows + + def get_random_image_and_flows(self, shape, image_type, flow_type): + batch_size, height, width, numchannels = shape + image_shape = [batch_size, height, width, numchannels] + image = np.random.normal(size=image_shape) + flow_shape = [batch_size, height, width, 2] + flows = np.random.normal(size=flow_shape) * 3 + return image.astype(image_type), flows.astype(flow_type) + + def assert_correct_interpolation_value(self, + image, + flows, + pred_interpolation, + batch_index, + y_index, + x_index, + low_precision=False): + """Assert that the tf interpolation matches hand-computed value.""" + + height = image.shape[1] + width = image.shape[2] + displacement = flows[batch_index, y_index, x_index, :] + float_y = y_index - displacement[0] + float_x = x_index - displacement[1] + floor_y = max(min(height - 2, math.floor(float_y)), 0) + floor_x = max(min(width - 2, math.floor(float_x)), 0) + ceil_y = floor_y + 1 + ceil_x = floor_x + 1 + + alpha_y = min(max(0.0, float_y - floor_y), 1.0) + alpha_x = min(max(0.0, float_x - floor_x), 1.0) + + floor_y = int(floor_y) + floor_x = int(floor_x) + ceil_y = int(ceil_y) + ceil_x = int(ceil_x) + + top_left = image[batch_index, floor_y, floor_x, :] + top_right = image[batch_index, floor_y, ceil_x, :] + bottom_left = image[batch_index, ceil_y, floor_x, :] + bottom_right = image[batch_index, ceil_y, ceil_x, :] + + interp_top = alpha_x * (top_right - top_left) + top_left + interp_bottom = alpha_x * (bottom_right - bottom_left) + bottom_left + interp = alpha_y * (interp_bottom - interp_top) + interp_top + atol = 1e-6 + rtol = 1e-6 + if low_precision: + atol = 1e-2 + rtol = 1e-3 + self.assertAllClose( + interp, + pred_interpolation[batch_index, y_index, x_index, :], + atol=atol, + rtol=rtol) + + def check_zero_flow_correctness(self, shape, image_type, flow_type): + """Assert using zero flows doesn't change the input image.""" + + image, flows = self.get_image_and_flow_placeholders(shape, image_type, + flow_type) + interp = dense_image_warp.dense_image_warp(image, flows) + + with self.test_session() as sess: + rand_image, rand_flows = self.get_random_image_and_flows( + shape, image_type, flow_type) + rand_flows *= 0 + + predicted_interpolation = sess.run( + interp, feed_dict={ + image: rand_image, + flows: rand_flows + }) + self.assertAllClose(rand_image, predicted_interpolation) + + def test_zero_flows(self): + """Apply check_zero_flow_correctness() for a few sizes and types.""" + + shapes_to_try = [[3, 4, 5, 6], [1, 2, 2, 1]] + for shape in shapes_to_try: + self.check_zero_flow_correctness( + shape, image_type='float32', flow_type='float32') + + def check_interpolation_correctness(self, + shape, + image_type, + flow_type, + num_probes=5): + """Interpolate, and then assert correctness for a few query locations.""" + + image, flows = self.get_image_and_flow_placeholders(shape, image_type, + flow_type) + interp = dense_image_warp.dense_image_warp(image, flows) + low_precision = image_type == 'float16' or flow_type == 'float16' + with self.test_session() as sess: + rand_image, rand_flows = self.get_random_image_and_flows( + shape, image_type, flow_type) + + pred_interpolation = sess.run( + interp, feed_dict={ + image: rand_image, + flows: rand_flows + }) + + for _ in range(num_probes): + batch_index = np.random.randint(0, shape[0]) + y_index = np.random.randint(0, shape[1]) + x_index = np.random.randint(0, shape[2]) + + self.assert_correct_interpolation_value( + rand_image, + rand_flows, + pred_interpolation, + batch_index, + y_index, + x_index, + low_precision=low_precision) + + def test_interpolation(self): + """Apply check_interpolation_correctness() for a few sizes and types.""" + + shapes_to_try = [[3, 4, 5, 6], [1, 5, 5, 3], [1, 2, 2, 1]] + for im_type in ['float32', 'float64', 'float16']: + for flow_type in ['float32', 'float64', 'float16']: + for shape in shapes_to_try: + self.check_interpolation_correctness(shape, im_type, flow_type) + + def test_gradients_exist(self): + """Check that backprop can run. + + The correctness of the gradients is assumed, since the forward propagation + is tested to be correct and we only use built-in tf ops. + However, we perform a simple test to make sure that backprop can actually + run. We treat the flows as a tf.Variable and optimize them to minimize + the difference between the interpolated image and the input image. + """ + + batch_size, height, width, numchannels = [4, 5, 6, 7] + image_shape = [batch_size, height, width, numchannels] + image = random_ops.random_normal(image_shape) + flow_shape = [batch_size, height, width, 2] + init_flows = np.float32(np.random.normal(size=flow_shape) * 0.25) + flows = variables.Variable(init_flows) + + interp = dense_image_warp.dense_image_warp(image, flows) + loss = math_ops.reduce_mean(math_ops.square(interp - image)) + + optimizer = adam.AdamOptimizer(1.0) + grad = gradients.gradients(loss, [flows]) + opt_func = optimizer.apply_gradients(zip(grad, [flows])) + init_op = variables.global_variables_initializer() + + with self.test_session() as sess: + sess.run(init_op) + for _ in range(10): + sess.run(opt_func) + + def test_size_exception(self): + """Make sure it throws an exception for images that are too small.""" + + shape = [1, 2, 1, 1] + msg = 'Should have raised an exception for invalid image size' + with self.assertRaises(ValueError, msg=msg): + self.check_interpolation_correctness(shape, 'float32', 'float32') + + +if __name__ == '__main__': + googletest.main() |