Implement tf.nn.atrous_conv2d_transpose. Close bugs #4668 and #5300.

Change: 140759688

3 files changed, 210 insertions, 28 deletions

diff --git a/tensorflow/python/kernel_tests/atrous_conv2d_test.py b/tensorflow/python/kernel_tests/atrous_conv2d_test.py
index 1dff6a9f72..162bebf8d6 100644
--- a/tensorflow/python/kernel_tests/atrous_conv2d_test.py
+++ b/tensorflow/python/kernel_tests/atrous_conv2d_test.py
@@ -22,33 +22,33 @@ import numpy as np
 import tensorflow as tf
 
 
-class AtrousConv2DTest(tf.test.TestCase):
-
-  def _upsample_filters(self, filters, rate):
-    """Upsamples the filters by a factor of rate along the spatial dimensions.
+def _upsample_filters(filters, rate):
+  """Upsamples the filters by a factor of rate along the spatial dimensions.
+
+  Args:
+    filters: [h, w, in_depth, out_depth]. Original filters.
+    rate: An int, specifying the upsampling rate.
+
+  Returns:
+    filters_up: [h_up, w_up, in_depth, out_depth]. Upsampled filters with
+      h_up = h + (h - 1) * (rate - 1)
+      w_up = w + (w - 1) * (rate - 1)
+      containing (rate - 1) zeros between consecutive filter values along
+      the filters' spatial dimensions.
+  """
+  if rate == 1:
+    return filters
+  # [h, w, in_depth, out_depth] -> [in_depth, out_depth, h, w]
+  filters_up = np.transpose(filters, [2, 3, 0, 1])
+  ker = np.zeros([rate, rate], dtype=np.float32)
+  ker[0, 0] = 1
+  filters_up = np.kron(filters_up, ker)[:, :, :-(rate-1), :-(rate-1)]
+  # [in_depth, out_depth, h_up, w_up] -> [h_up, w_up, in_depth, out_depth]
+  filters_up = np.transpose(filters_up, [2, 3, 0, 1])
+  return filters_up
 
-    Args:
-      filters: [h, w, in_depth, out_depth]. Original filters.
-      rate: An int, specifying the upsampling rate.
 
-    Returns:
-      filters_up: [h_up, w_up, in_depth, out_depth]. Upsampled filters with
-        h_up = h + (h - 1) * (rate - 1)
-        w_up = w + (w - 1) * (rate - 1)
-        containing (rate - 1) zeros between consecutive filter values along
-        the filters' spatial dimensions.
-    """
-    if rate == 1:
-      return filters
-    # [h, w, in_depth, out_depth] -> [in_depth, out_depth, h, w]
-    filters_up = np.transpose(filters, [2, 3, 0, 1])
-    ker = np.zeros([rate, rate])
-    ker[0, 0] = 1
-    filters_up = np.kron(filters_up, ker)[:, :, :-(rate-1), :-(rate-1)]
-    # [in_depth, out_depth, h_up, w_up] -> [h_up, w_up, in_depth, out_depth]
-    filters_up = np.transpose(filters_up, [2, 3, 0, 1])
-    self.assertEqual(np.sum(filters), np.sum(filters_up))
-    return filters_up
+class AtrousConv2DTest(tf.test.TestCase):
 
   def testAtrousConv2DForward(self):
     with self.test_session(use_gpu=True):
@@ -65,14 +65,13 @@ class AtrousConv2DTest(tf.test.TestCase):
             f = np.arange(np.prod(f_shape), dtype=np.float32).reshape(f_shape)
 
             for rate in range(1, 4):
-              f_up = self._upsample_filters(f, rate)
+              f_up = _upsample_filters(f, rate)
 
               for padding in ["SAME", "VALID"]:
                 y1 = tf.nn.atrous_conv2d(x, f, rate, padding=padding)
                 y2 = tf.nn.conv2d(x, f_up, strides=[1, 1, 1, 1],
                                   padding=padding)
-                self.assertAllClose(y1.eval(), y2.eval(), rtol=1e-2,
-                                    atol=1e-2)
+                self.assertAllClose(y1.eval(), y2.eval(), rtol=1e-3, atol=1e-3)
 
   def testAtrousSequence(self):
     """Tests optimization of sequence of atrous convolutions.
@@ -150,5 +149,42 @@ class AtrousConv2DTest(tf.test.TestCase):
         self.assertLess(err, err_tolerance)
 
 
+class AtrousConv2DTransposeTest(tf.test.TestCase):
+
+  def testAtrousConv2DTransposeForward(self):
+    with self.test_session(use_gpu=True):
+      # Input: [batch, height, width, input_depth]
+      height = 9
+      for width in [9, 10]:  # Test both odd and even width.
+        x_shape = [2, height, width, 2]
+        x = np.arange(np.prod(x_shape), dtype=np.float32).reshape(x_shape)
+
+        # Filter: [kernel_height, kernel_width, input_depth, output_depth]
+        for kernel_height in range(1, 4):
+          for kernel_width in range(1, 4):
+            f_shape = [kernel_height, kernel_width, 2, 2]
+            f = np.arange(np.prod(f_shape), dtype=np.float32).reshape(f_shape)
+
+            for rate in range(1, 4):
+              f_up = _upsample_filters(f, rate)
+              kernel_height_up = (kernel_height +
+                                  (kernel_height - 1) * (rate - 1))
+              kernel_width_up = kernel_width + (kernel_width - 1) * (rate - 1)
+
+              for padding in ["SAME", "VALID"]:
+                if padding == "SAME":
+                  y_shape = [2, height, width, 2]
+                else:
+                  y_shape = [2,
+                             height + kernel_height_up - 1,
+                             width + kernel_width_up - 1,
+                             2]
+
+                y1 = tf.nn.atrous_conv2d_transpose(x, f, y_shape, rate, padding)
+                y2 = tf.nn.conv2d_transpose(
+                    x, f_up, y_shape, strides=[1, 1, 1, 1], padding=padding)
+                self.assertAllClose(y1.eval(), y2.eval(), rtol=1e-3, atol=1e-3)
+
+
 if __name__ == "__main__":
   tf.test.main()
diff --git a/tensorflow/python/ops/nn.py b/tensorflow/python/ops/nn.py
index 601984799c..da1b880d32 100644
--- a/tensorflow/python/ops/nn.py
+++ b/tensorflow/python/ops/nn.py
@@ -110,6 +110,7 @@ concatenated.
 @@depthwise_conv2d_native
 @@separable_conv2d
 @@atrous_conv2d
+@@atrous_conv2d_transpose
 @@conv2d_transpose
 @@conv1d
 @@conv3d
diff --git a/tensorflow/python/ops/nn_ops.py b/tensorflow/python/ops/nn_ops.py
index 35610cc554..b2c6cf7138 100644
--- a/tensorflow/python/ops/nn_ops.py
+++ b/tensorflow/python/ops/nn_ops.py
@@ -1078,6 +1078,151 @@ def conv2d_transpose(value,
                                             name=name)
 
 
+def atrous_conv2d_transpose(value,
+                            filters,
+                            output_shape,
+                            rate,
+                            padding,
+                            name=None):
+  """The transpose of `atrous_conv2d`.
+
+  This operation is sometimes called "deconvolution" after [Deconvolutional
+  Networks](http://www.matthewzeiler.com/pubs/cvpr2010/cvpr2010.pdf), but is
+  actually the transpose (gradient) of `atrous_conv2d` rather than an actual
+  deconvolution.
+
+  Args:
+    value: A 4-D `Tensor` of type `float`. It needs to be in the default `NHWC`
+      format. Its shape is `[batch, in_height, in_width, in_channels]`.
+    filters: A 4-D `Tensor` with the same type as `value` and shape
+      `[filter_height, filter_width, out_channels, in_channels]`. `filters`'
+      `in_channels` dimension must match that of `value`. Atrous convolution is
+      equivalent to standard convolution with upsampled filters with effective
+      height `filter_height + (filter_height - 1) * (rate - 1)` and effective
+      width `filter_width + (filter_width - 1) * (rate - 1)`, produced by
+      inserting `rate - 1` zeros along consecutive elements across the
+      `filters`' spatial dimensions.
+    output_shape: A 1-D `Tensor` of shape representing the output shape of the
+      deconvolution op.
+    rate: A positive int32. The stride with which we sample input values across
+      the `height` and `width` dimensions. Equivalently, the rate by which we
+      upsample the filter values by inserting zeros across the `height` and
+      `width` dimensions. In the literature, the same parameter is sometimes
+      called `input stride` or `dilation`.
+    padding: A string, either `'VALID'` or `'SAME'`. The padding algorithm.
+    name: Optional name for the returned tensor.
+
+  Returns:
+    A `Tensor` with the same type as `value`.
+
+  Raises:
+    ValueError: If input/output depth does not match `filters`' shape, or if
+      padding is other than `'VALID'` or `'SAME'`, or if the `rate` is less
+      than one, or if the output_shape is not a tensor with 4 elements.
+  """
+  with ops.name_scope(name, "atrous_conv2d_transpose",
+                      [value, filters, output_shape]) as name:
+    value = ops.convert_to_tensor(value, name="value")
+    filters = ops.convert_to_tensor(filters, name="filters")
+    if not value.get_shape()[3].is_compatible_with(filters.get_shape()[3]):
+      raise ValueError(
+          "value's input channels does not match filters' input channels, "
+          "{} != {}".format(value.get_shape()[3], filters.get_shape()[3]))
+    if rate < 1:
+      raise ValueError("rate {} cannot be less than one".format(rate))
+
+    if rate == 1:
+      return conv2d_transpose(value,
+                              filters,
+                              output_shape,
+                              strides=[1, 1, 1, 1],
+                              padding=padding,
+                              data_format="NHWC")
+
+    output_shape_ = ops.convert_to_tensor(output_shape, name="output_shape")
+    if not output_shape_.get_shape().is_compatible_with(tensor_shape.vector(4)):
+      raise ValueError("output_shape must have shape (4,), got {}"
+                       .format(output_shape_.get_shape()))
+
+    if isinstance(output_shape, (list, np.ndarray)):
+      # output_shape's shape should be == [4] if reached this point.
+      if not filters.get_shape()[2].is_compatible_with(output_shape[3]):
+        raise ValueError(
+            "output_shape does not match filter's output channels, "
+            "{} != {}".format(output_shape[3], filters.get_shape()[2]))
+
+    # We have two padding contributions. The first is used for converting "SAME"
+    # to "VALID". The second is required so that the height and width of the
+    # zero-padded value tensor are multiples of rate.
+
+    # Padding required to reduce to "VALID" convolution
+    if padding == "SAME":
+      # Handle filters whose shape is unknown during graph creation.
+      if filters.get_shape().is_fully_defined():
+        filter_shape = filters.get_shape().as_list()
+      else:
+        filter_shape = array_ops.shape(filters)
+      filter_height, filter_width = filter_shape[0], filter_shape[1]
+
+      # Spatial dimensions of the filters and the upsampled filters in which we
+      # introduce (rate - 1) zeros between consecutive filter values.
+      filter_height_up = filter_height + (filter_height - 1) * (rate - 1)
+      filter_width_up = filter_width + (filter_width - 1) * (rate - 1)
+
+      pad_height = filter_height_up - 1
+      pad_width = filter_width_up - 1
+
+      # When pad_height (pad_width) is odd, we pad more to bottom (right),
+      # following the same convention as conv2d().
+      pad_top = pad_height // 2
+      pad_bottom = pad_height - pad_top
+      pad_left = pad_width // 2
+      pad_right = pad_width - pad_left
+    elif padding == "VALID":
+      pad_top = 0
+      pad_bottom = 0
+      pad_left = 0
+      pad_right = 0
+    else:
+      raise ValueError("padding must be either VALID or SAME:"
+                       " {}".format(padding))
+
+    in_height = output_shape[1] + pad_top + pad_bottom
+    in_width = output_shape[2] + pad_left + pad_right
+
+    # More padding so that rate divides the height and width of the input.
+    pad_bottom_extra = (rate - in_height % rate) % rate
+    pad_right_extra = (rate - in_width % rate) % rate
+
+    # The paddings argument to space_to_batch is just the extra padding
+    # component.
+    space_to_batch_pad = [[0, pad_bottom_extra], [0, pad_right_extra]]
+
+    value = array_ops.space_to_batch(input=value,
+                                     paddings=space_to_batch_pad,
+                                     block_size=rate)
+
+    input_sizes = [rate * rate * output_shape[0],
+                   (in_height + pad_bottom_extra) // rate,
+                   (in_width + pad_right_extra) // rate,
+                   output_shape[3]]
+
+    value = gen_nn_ops.conv2d_backprop_input(input_sizes=input_sizes,
+                                             filter=filters,
+                                             out_backprop=value,
+                                             strides=[1, 1, 1, 1],
+                                             padding="VALID",
+                                             data_format="NHWC")
+
+    # The crops argument to batch_to_space includes both padding components.
+    batch_to_space_crop = [[pad_top, pad_bottom + pad_bottom_extra],
+                           [pad_left, pad_right + pad_right_extra]]
+
+    return array_ops.batch_to_space(input=value,
+                                    crops=batch_to_space_crop,
+                                    block_size=rate)
+
+
 def conv3d_transpose(value,
                      filter,
                      output_shape,