diff --git a/src/TensorFlowNET.Core/APIs/tf.image.cs b/src/TensorFlowNET.Core/APIs/tf.image.cs
index 61c91052..e2e3206b 100644
--- a/src/TensorFlowNET.Core/APIs/tf.image.cs
+++ b/src/TensorFlowNET.Core/APIs/tf.image.cs
@@ -42,6 +42,20 @@ namespace Tensorflow
 
             public Tensor convert_image_dtype(Tensor image, TF_DataType dtype, bool saturate = false, string name = null)
                 => gen_image_ops.convert_image_dtype(image, dtype, saturate: saturate, name: name);
+
+            public Tensor decode_image(Tensor contents, int channels = 0, TF_DataType dtype = TF_DataType.TF_UINT8,
+                string name = null, bool expand_animations = true)
+                => image_ops_impl.decode_image(contents, channels: channels, dtype: dtype,
+                    name: name, expand_animations: expand_animations);
+
+            /// <summary>
+            /// Convenience function to check if the 'contents' encodes a JPEG image.
+            /// </summary>
+            /// <param name="contents"></param>
+            /// <param name="name"></param>
+            /// <returns></returns>
+            public static Tensor is_jpeg(Tensor contents, string name = null)
+                => image_ops_impl.is_jpeg(contents, name: name);
         }
     }
 }
diff --git a/src/TensorFlowNET.Core/APIs/tf.strings.cs b/src/TensorFlowNET.Core/APIs/tf.strings.cs
new file mode 100644
index 00000000..38d92803
--- /dev/null
+++ b/src/TensorFlowNET.Core/APIs/tf.strings.cs
@@ -0,0 +1,32 @@
+/*****************************************************************************
+   Copyright 2018 The TensorFlow.NET 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.
+******************************************************************************/
+
+using System.Collections.Generic;
+using Tensorflow.IO;
+
+namespace Tensorflow
+{
+    public partial class tensorflow
+    {
+        public strings_internal strings = new strings_internal();
+        public class strings_internal
+        {
+            public Tensor substr(Tensor input, int pos, int len,
+                    string name = null, string @uint = "BYTE")
+                => string_ops.substr(input, pos, len, name: name, @uint: @uint);
+        }
+    }
+}
diff --git a/src/TensorFlowNET.Core/Operations/gen_image_ops.py.cs b/src/TensorFlowNET.Core/Operations/gen_image_ops.py.cs
index 3cd1a83e..90893815 100644
--- a/src/TensorFlowNET.Core/Operations/gen_image_ops.py.cs
+++ b/src/TensorFlowNET.Core/Operations/gen_image_ops.py.cs
@@ -88,6 +88,69 @@ namespace Tensorflow
             }
         }
 
+        public static Tensor decode_gif(Tensor contents,
+            string name = null)
+        {
+            // Add nodes to the TensorFlow graph.
+            if (tf.context.executing_eagerly())
+            {
+                throw new NotImplementedException("decode_gif");
+            }
+            else
+            {
+                var _op = _op_def_lib._apply_op_helper("DecodeGif", name: name, args: new
+                {
+                    contents
+                });
+
+                return _op.output;
+            }
+        }
+
+        public static Tensor decode_png(Tensor contents,
+            int channels = 0,
+            TF_DataType dtype = TF_DataType.TF_UINT8,
+            string name = null)
+        {
+            // Add nodes to the TensorFlow graph.
+            if (tf.context.executing_eagerly())
+            {
+                throw new NotImplementedException("decode_png");
+            }
+            else
+            {
+                var _op = _op_def_lib._apply_op_helper("DecodePng", name: name, args: new
+                {
+                    contents,
+                    channels,
+                    dtype
+                });
+
+                return _op.output;
+            }
+        }
+
+        public static Tensor decode_bmp(Tensor contents,
+            int channels = 0,
+            string name = null)
+        {
+            // Add nodes to the TensorFlow graph.
+            if (tf.context.executing_eagerly())
+            {
+                throw new NotImplementedException("decode_bmp");
+            }
+            else
+            {
+                var _op = _op_def_lib._apply_op_helper("DecodeBmp", name: name, args: new
+                {
+                    contents,
+                    channels
+                });
+
+                return _op.output;
+            }
+        }
+
         public static Tensor resize_bilinear(Tensor images, Tensor size, bool align_corners = false, string name = null)
         {
             if (tf.context.executing_eagerly())
diff --git a/src/TensorFlowNET.Core/Operations/gen_string_ops.cs b/src/TensorFlowNET.Core/Operations/gen_string_ops.cs
new file mode 100644
index 00000000..87ac589e
--- /dev/null
+++ b/src/TensorFlowNET.Core/Operations/gen_string_ops.cs
@@ -0,0 +1,42 @@
+/*****************************************************************************
+   Copyright 2018 The TensorFlow.NET 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.
+******************************************************************************/
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow
+{
+    public class gen_string_ops
+    {
+        static readonly OpDefLibrary _op_def_lib;
+        static gen_string_ops() { _op_def_lib = new OpDefLibrary(); }
+
+        public static Tensor substr(Tensor input, int pos, int len, 
+            string name = null, string @uint = "BYTE")
+        {
+            var _op = _op_def_lib._apply_op_helper("Substr", name: name, args: new
+            {
+                input,
+                pos,
+                len,
+                unit = @uint
+            });
+
+            return _op.output;
+        }
+    }
+}
diff --git a/src/TensorFlowNET.Core/Operations/image_ops_impl.cs b/src/TensorFlowNET.Core/Operations/image_ops_impl.cs
index d21f6e8d..65ed8eb1 100644
--- a/src/TensorFlowNET.Core/Operations/image_ops_impl.cs
+++ b/src/TensorFlowNET.Core/Operations/image_ops_impl.cs
@@ -17,11 +17,116 @@
 using System;
 using System.Collections.Generic;
 using System.Text;
+using static Tensorflow.Binding;
 
 namespace Tensorflow
 {
     public class image_ops_impl
     {
+        public static Tensor decode_image(Tensor contents, int channels = 0, TF_DataType dtype = TF_DataType.TF_UINT8,
+            string name = null, bool expand_animations = true)
+        {
+            Tensor substr = null;
 
+            Func<ITensorOrOperation> _jpeg = () =>
+            {
+                int jpeg_channels = channels;
+                var good_channels = math_ops.not_equal(jpeg_channels, 4, name: "check_jpeg_channels");
+                string channels_msg = "Channels must be in (None, 0, 1, 3) when decoding JPEG 'images'";
+                var assert_channels = control_flow_ops.Assert(good_channels, new string[] { channels_msg });
+                return tf_with(ops.control_dependencies(new[] { assert_channels }), delegate
+                {
+                    return convert_image_dtype(gen_image_ops.decode_jpeg(contents, channels), dtype);
+                });
+            };
+
+            Func<ITensorOrOperation> _gif = () =>
+            {
+                int gif_channels = channels;
+                var good_channels = math_ops.logical_and(
+                  math_ops.not_equal(gif_channels, 1, name: "check_gif_channels"),
+                  math_ops.not_equal(gif_channels, 4, name: "check_gif_channels"));
+
+                string channels_msg = "Channels must be in (None, 0, 3) when decoding GIF images";
+                var assert_channels = control_flow_ops.Assert(good_channels, new string[] { channels_msg });
+                return tf_with(ops.control_dependencies(new[] { assert_channels }), delegate
+                {
+                    var result = convert_image_dtype(gen_image_ops.decode_gif(contents), dtype);
+                    if (!expand_animations)
+                        // result = array_ops.gather(result, 0);
+                        throw new NotImplementedException("");
+                    return result;
+                });
+            };
+
+            Func<ITensorOrOperation> _bmp = () =>
+            {
+                int bmp_channels = channels;
+                var signature = string_ops.substr(contents, 0, 2);
+                var is_bmp = math_ops.equal(signature, "BM", name: "is_bmp");
+                string decode_msg = "Unable to decode bytes as JPEG, PNG, GIF, or BMP";
+                var assert_decode = control_flow_ops.Assert(is_bmp, new string[] { decode_msg });
+                var good_channels = math_ops.not_equal(bmp_channels, 1, name: "check_channels");
+                string channels_msg = "Channels must be in (None, 0, 3) when decoding BMP images";
+                var assert_channels = control_flow_ops.Assert(good_channels, new string[] { channels_msg });
+                return tf_with(ops.control_dependencies(new[] { assert_decode, assert_channels }), delegate
+                {
+                    return convert_image_dtype(gen_image_ops.decode_bmp(contents), dtype);
+                });
+            };
+
+            Func<ITensorOrOperation> _png = () =>
+            {
+                return convert_image_dtype(gen_image_ops.decode_png(
+                      contents,
+                      channels,
+                      dtype: dtype),
+                      dtype);
+            };
+
+            Func<ITensorOrOperation> check_gif = () =>
+            {
+                var is_gif = math_ops.equal(substr, "\x47\x49\x46", name: "is_gif");
+                return control_flow_ops.cond(is_gif, _gif, _bmp, name: "cond_gif");
+            };
+
+            Func<ITensorOrOperation> check_png = () =>
+            {
+                return control_flow_ops.cond(_is_png(contents), _png, check_gif, name: "cond_png");
+            };
+
+            return tf_with(ops.name_scope(name, "decode_image"), scope =>
+            {
+                substr = string_ops.substr(contents, 0, 3);
+                return control_flow_ops.cond(is_jpeg(contents), _jpeg, check_png, name: "cond_jpeg");
+            });
+        }
+
+        public static Tensor is_jpeg(Tensor contents, string name = null)
+        {
+            return tf_with(ops.name_scope(name, "is_jpeg"), scope =>
+            {
+                var substr = string_ops.substr(contents, 0, 3);
+                return math_ops.equal(substr, "\xff\xd8\xff", name: name);
+            });
+        }
+
+        public static Tensor _is_png(Tensor contents, string name = null)
+        {
+            return tf_with(ops.name_scope(name, "is_png"), scope =>
+            {
+                var substr = string_ops.substr(contents, 0, 3);
+                return math_ops.equal(substr, @"\211PN", name: name);
+            });
+        }
+
+        public static Tensor convert_image_dtype(Tensor image, TF_DataType dtype, bool saturate = false, 
+            string name = null)
+        {
+            if (dtype == image.dtype)
+                return array_ops.identity(image, name: name);
+
+            throw new NotImplementedException("");
+        }
     }
 }
diff --git a/src/TensorFlowNET.Core/Operations/math_ops.cs b/src/TensorFlowNET.Core/Operations/math_ops.cs
index fa1fda12..f5cfdb37 100644
--- a/src/TensorFlowNET.Core/Operations/math_ops.cs
+++ b/src/TensorFlowNET.Core/Operations/math_ops.cs
@@ -168,6 +168,9 @@ namespace Tensorflow
         public static Tensor multiply<Tx, Ty>(Tx x, Ty y, string name = null)
             => gen_math_ops.mul(x, y, name: name);
 
+        public static Tensor not_equal<Tx, Ty>(Tx x, Ty y, string name = null)
+            => gen_math_ops.not_equal(x, y, name: name);
+
         public static Tensor mul_no_nan<Tx, Ty>(Tx x, Ty y, string name = null)
             => gen_math_ops.mul_no_nan(x, y, name: name);
 
@@ -264,6 +267,9 @@ namespace Tensorflow
             return gen_math_ops.log(x, name);
         }
 
+        public static Tensor logical_and(Tensor x, Tensor y, string name = null)
+            => gen_math_ops.logical_and(x, y, name: name);
+
         public static Tensor lgamma(Tensor x, string name = null)
             => gen_math_ops.lgamma(x, name: name);
 
diff --git a/src/TensorFlowNET.Core/Operations/string_ops.cs b/src/TensorFlowNET.Core/Operations/string_ops.cs
new file mode 100644
index 00000000..ee46cf78
--- /dev/null
+++ b/src/TensorFlowNET.Core/Operations/string_ops.cs
@@ -0,0 +1,38 @@
+/*****************************************************************************
+   Copyright 2018 The TensorFlow.NET 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.
+******************************************************************************/
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Tensorflow
+{
+    public class string_ops
+    {
+        /// <summary>
+        /// Return substrings from `Tensor` of strings.
+        /// </summary>
+        /// <param name="input"></param>
+        /// <param name="pos"></param>
+        /// <param name="len"></param>
+        /// <param name="name"></param>
+        /// <param name="uint"></param>
+        /// <returns></returns>
+        public static Tensor substr(Tensor input, int pos, int len,
+                string name = null, string @uint = "BYTE")
+            => gen_string_ops.substr(input, pos, len, name: name, @uint: @uint);
+    }
+}
diff --git a/test/TensorFlowNET.UnitTest/GraphTest.cs b/test/TensorFlowNET.UnitTest/GraphTest.cs
index f5431e01..c088d7e6 100644
--- a/test/TensorFlowNET.UnitTest/GraphTest.cs
+++ b/test/TensorFlowNET.UnitTest/GraphTest.cs
@@ -416,12 +416,13 @@ namespace TensorFlowNET.UnitTest
 
         }
 
+        [TestMethod]
         public void ImportGraphMeta()
         {
             var dir = "my-save-dir/";
             using (var sess = tf.Session())
             {
-                var new_saver = tf.train.import_meta_graph(dir + "my-model-10000.meta");
+                var new_saver = tf.train.import_meta_graph(@"D:\tmp\resnet_v2_101_2017_04_14\eval.graph");
                 new_saver.restore(sess, dir + "my-model-10000");
                 var labels = tf.constant(0, dtype: tf.int32, shape: new int[] { 100 }, name: "labels");
                 var batch_size = tf.size(labels);
diff --git a/test/TensorFlowNET.UnitTest/ImageTest.cs b/test/TensorFlowNET.UnitTest/ImageTest.cs
new file mode 100644
index 00000000..4b6d5922
--- /dev/null
+++ b/test/TensorFlowNET.UnitTest/ImageTest.cs
@@ -0,0 +1,30 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using Tensorflow;
+using static Tensorflow.Binding;
+
+namespace TensorFlowNET.UnitTest
+{
+    [TestClass]
+    public class ImageTest
+    {
+        string imgPath = "../../../../../data/shasta-daisy.jpg";
+        Tensor contents;
+
+        public ImageTest()
+        {
+            imgPath = Path.GetFullPath(imgPath);
+            contents = tf.read_file(imgPath);
+        }
+
+        [TestMethod]
+        public void decode_image()
+        {
+            var img = tf.image.decode_image(contents);
+            Assert.AreEqual(img.name, "decode_image/cond_jpeg/Merge:0");
+        }
+    }
+}