[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."

[Shell] The example shell script of automation way to build the software or library required

I don't like to preach at people. But, if someone has a task that has been done more than two times, then he/she should consider using an automation way to ease the burden. One of the solutions is by writing a shell script. Here is an example of building OpenCV 3.4.1 on TX2 using a shell script. The software or the target platform is not the key part. The most important part is to adopt this sort of shell script to become the one of your version.

[Tool] Visdom is a great visualization tool

I cannot use my word to describe Visdom because it is so amazingly awesome. Referencing the introduction from Facebook AI's official site,Visdom is a visualization tool that generates rich visualizations of live data to help researchers and developers stay on top of their scientific experiments that are run on remote servers. Visualizations in Visdom can be viewed in browsers and easily shared with others.

[TensorRT] How to use TensorRT to do inference with TensorFlow model ?

TensorRT is a high-performance deep learning inference optimizer and runtime that delivers low latency, high-throughput inference for deep learning applications. Here I am going to demonstrate that how to use TensorRT to do inference with TensorFlow model.


Install TensorRT
Please refer to this official website first:
https://docs.nvidia.com/deeplearning/sdk/tensorrt-install-guide/index.html#installing
After downloading TensorRT 4.0 ( in my case ), we can install it.

$ dpkg -i nv-tensorrt-repo-ubuntu1604-cuda9.0-ga-trt4.0.1.6-20180612_1-1_amd64.deb
$ apt-get update
$ apt-get install tensorrt
$ apt-get install python-libnvinfer-dev
$ apt-get install uff-converter-tf