[TensorFlow] Build TensorFlow v1.12 from the source on Ubuntu 16.04

My previous post: [TensorFlow] How to build your C++ program or application with TensorFlow library using CMake

It is for building TensorFlow from the source based on v1.10. Currently, I want to upgrade it to v1.12 and encounter some problems. 

First, my version of ProtoBuf library on my system is v3.6.1 so that we should align its version in the TensorFlow.
Second, it seems that there are a few issues when building TensorFlow v1.12 that we need to deal with it case by case.

[TensorFlow Lite] My first try with TensorFlow Lite

I just take my first try with the example: label_image (tensorflow/contrib/lite/examples/label_image) in TensorFlow Lite and write down the commands that I used.
There are a bunch of information from the offical TensorFlow Lite guide:
https://www.tensorflow.org/lite/guide

1. convert the example of model to tflite format

[Tool] Convert TensorFlow graph to UFF format

The previous post: How to use TensorRT to do inference with TensorFlow model ? has introduced away to do the converting job for UFF format model. But, basically there are 2 ways to do that:

1. Convert TensorFlow's Session GraphDef directly on the fly to UFF format model
    ==> convert_uff_from_tensorflow()
2. Convert the frozen model file to UFF format model
    ==> convert_uff_from_frozen_model()

The following code is about the functions to convert TensorFlow graph to UFF format for running with TensorRT.

[OpenCV] Build OpenCV 3.4.4 on TX2

For the reason that I was curious about the performance of OpenCV on TX2 using GPU, I installed OpenCV 3.4.4 (this version and after will integrate with the inference engine) on my TX2 based on the following links.
https://jkjung-avt.github.io/opencv3-on-tx2/
https://www.learnopencv.com/install-opencv-3-4-4-on-ubuntu-16-04/

[Inspecting Graphs] Use TensorFlow's summarize_graph tool to find the input and output node names in the frozen model/graph

When trying to do inferencing using a frozen model from downloading or freezing by yourself, we may encounter a problem about what the input and output node names are in this model? If we cannot figure them out, it is impossible for you to do inferencing correctly. Here is an easy way to get the possible ones: using the tool: "summarize_graph"

bazel build tensorflow/tools/graph_transforms:summarize_graph
bazel-bin/tensorflow/tools/graph_transforms/summarize_graph --in_graph=/danny/tmp/faster_rcnn_resnet101_coco_2018_01_28/frozen_inference_graph.pb

Found 1 possible inputs: (name=image_tensor, type=uint8(4), shape=[?,?,?,3])
No variables spotted.
Found 4 possible outputs: (name=detection_boxes, op=Identity) (name=detection_scores, op=Identity) (name=num_detections, op=Identity) (name=detection_classes, op=Identity)
Found 48132698 (48.13M) const parameters, 0 (0) variable parameters, and 4163 control_edges
Op types used: 4688 Const, 885 StridedSlice, 559 Gather, 485 Mul, 472 Sub, 462 Minimum, 369 Maximum, 304 Reshape, 276 Split, 205 RealDiv, 204 Pack, 202 ConcatV2, 201 Cast, 188 Greater, 183 Where, 149 Shape, 145 Add, 109 BiasAdd, 107 Conv2D, 106 Slice, 100 Relu, 99 Unpack, 97 Squeeze, 94 ZerosLike, 91 NonMaxSuppressionV2, 55 Enter, 46 Identity, 45 Switch, 27 Range, 24 Merge, 22 TensorArrayV3, 17 ExpandDims, 15 NextIteration, 12 TensorArrayScatterV3, 12 TensorArrayReadV3, 10 TensorArrayWriteV3, 10 Exit, 10 Tile, 10 TensorArrayGatherV3, 10 TensorArraySizeV3, 6 Transpose, 6 Fill, 6 Assert, 5 Less, 5 LoopCond, 5 Equal, 4 Round, 4 Exp, 4 MaxPool, 3 Pad, 2 Softmax, 2 Size, 2 GreaterEqual, 2 TopKV2, 2 MatMul, 1 All, 1 CropAndResize, 1 ResizeBilinear, 1 Relu6, 1 Placeholder, 1 LogicalAnd, 1 Max, 1 Mean
To use with tensorflow/tools/benchmark:benchmark_model try these arguments:
bazel run tensorflow/tools/benchmark:benchmark_model -- --graph=/danny/tmp/faster_rcnn_resnet101_coco_2018_01_28/frozen_inference_graph.pb --show_flops --input_layer=image_tensor --input_layer_type=uint8 --input_layer_shape=-1,-1,-1,3 --output_layer=detection_boxes,detection_scores,num_detections,detection_classes

For more information, please refer to this:
https://github.com/tensorflow/tensorflow/tree/master/tensorflow/tools/graph_transforms#inspecting-graphs

[TFRecord] The easy way to verify your TFRecord file

There is a common situation when you build your TFRecord file ( your dataset ) and want to verify the correctness of the data in it. How to do it? I assume you don't have the problem to build your TFRecord file. So, the easy way to verify your TFRecord file is to use the API: tf.python_io.tf_record_iterator(). 

[TensorFlow] How to use Distribution Strategy in TensorFlow?

Learned from What’s coming in TensorFlow 2.0, TensorFlow 2.0 is coming soon and there are several features which are ready to use already, for instance, Distribution Strategy. Quoted from the article,
"For large ML training tasks, the Distribution Strategy API makes it easy to distribute and train models on different hardware configurations without changing the model definition. Since TensorFlow provides support for a range of hardware accelerators like CPUs, GPUs, and TPUs, you can enable training workloads to be distributed to single-node/multi-accelerator as well as multi-node/multi-accelerator configurations, including TPU Pods. Although this API supports a variety of cluster configurations, templates to deploy training on Kubernetes clusters in on-prem or cloud environments are provided."