Fixed half_pixel_centers for resize_nearest_neighbor

Signed-off-by: Tom Wildenhain <tomwi@microsoft.com>

Author: TomWildenhain-Microsoft

tests/test_backend.py

@@ -2101,6 +2101,19 @@ def func(x):
             return tf.identity(x_, name=_TFOUTPUT)
         _ = self._run_test_case(func, [_OUTPUT], {_INPUT: x_val})
 
+    @skip_caffe2_backend()
+    @check_tf_min_version("1.14")
+    @check_opset_min_version(11, "coordinate_transformation_mode attr")
+    def test_resize_bilinear_half_pixel_centers(self):
+        x_shape = [1, 15, 20, 2]
+        x_new_size = [30, 40]
+        x_val = np.arange(1, 1 + np.prod(x_shape)).astype("float32").reshape(x_shape)
+        def func(x):
+            x_new_size_ = tf.constant(x_new_size)
+            x_ = resize_bilinear(x, x_new_size_, half_pixel_centers=True)
+            return tf.identity(x_, name=_TFOUTPUT)
+        _ = self._run_test_case(func, [_OUTPUT], {_INPUT: x_val})
+
     @check_opset_min_version(9, "resize_bilinear")
     def test_resize_bilinear_with_non_const(self):
         x_shape = [3, 10, 8, 5]
@@ -2144,6 +2157,18 @@ def func(x):
             return tf.identity(x_, name=_TFOUTPUT)
         _ = self._run_test_case(func, [_OUTPUT], {_INPUT: x_val})
 
+    @check_tf_min_version("1.14")
+    @check_opset_min_version(11, "coordinate_transformation_mode attr")
+    def test_resize_nearest_neighbor_half_pixel_centers(self):
+        x_shape = [1, 10, 20, 2]
+        x_new_size = [20, 40]
+        x_val = np.arange(1, 1 + np.prod(x_shape)).astype("float32").reshape(x_shape)
+        def func(x):
+            x_new_size_ = tf.constant(x_new_size)
+            x_ = resize_nearest_neighbor(x, x_new_size_, half_pixel_centers=True)
+            return tf.identity(x_, name=_TFOUTPUT)
+        _ = self._run_test_case(func, [_OUTPUT], {_INPUT: x_val})
+
     @check_opset_min_version(9, "fill")
     def test_fill_float32(self):
         x_shape = [1, 15, 20, 2]

tf2onnx/onnx_opset/nn.py

@@ -903,7 +903,10 @@ def version_11(cls, ctx, node, **kwargs):
         if "align_corners" in node.attr and node.attr["align_corners"].i:
             transformation_mode = "align_corners"
         if "half_pixel_centers" in node.attr and node.attr["half_pixel_centers"].i:
-            transformation_mode = "half_pixel"
+            if node.type == "ResizeNearestNeighbor":
+                transformation_mode = "tf_half_pixel_for_nn"
+            else:
+                transformation_mode = "half_pixel"
         resize = ctx.make_node("Resize", resize_inputs,
                                attr={"mode": mode, "nearest_mode": "floor",
                                      "coordinate_transformation_mode": transformation_mode})