Pytorch-C++
Pytorch-C++
is a simple C++ 11 library which provides a Pytorch-like
interface for building neural networks and inference (so far only forward pass is supported). The library
respects the semantics of torch.nn
module of PyTorch. Models from pytorch/vision
are supported and can be easily converted. We also support all the models from our image segmentation repository (scroll down for the gif with example output of one of our segmentation models).
The library heavily relies on an amazing ATen library and was inspired by cunnproduction.
The structure of the project and CMake will be changed in a future, as it is not optimal now.
Table of contents
Use-cases
Examples
Implemented layers
Implemented models
Demos
Installation
About
Contributors
Use-cases
The library can be used in cases where you want to integrate your trained Pytorch
networks into an existing C++ stack and you don't want to convert your weights to other libraries
like Caffe/Caffe2/Tensorflow
. The library respects the semantics of the Pytorch
and uses
the same underlying C library to perform all the operations.
You can achieve more low-level control over your memory. For example, you can use a memory that was already allocated on GPU. This way you can accept memory from other application on GPU and avoid expensive transfer to CPU. See this example.
Conversion from other image types like OpenCV's mat
to Tensor
can be easily performed and all the post-processing
can be done using numpy-like optimized operations, thanks to ATen library.
See examples here.
Some examples
Inference
auto net = torch::resnet50_imagenet();
net->load_weights("../resnet50_imagenet.h5");
# Transfer network to GPU
net->cuda();
# Generate a dummy tensor on GPU of type float
Tensor dummy_input = CUDA(kFloat).ones({1, 3, 224, 224});
# Perform inference
auto result = net->forward(dummy_input);
map<string, Tensor> dict;
# Get the result of the inference back to CPU
dict["main"] = result.toBackend(Backend::CPU);
# Save the result of the inference in the HDF5 file
torch::save("resnet50_output.h5", dict);
Display network's architecture
auto net = torch::resnet50_imagenet();
net->load_weights("../resnet50_imagenet.h5");
cout << net->tostring() << endl;
Output:
ResNet (
(conv1) Conv2d( in_channels=3 out_channels=64 kernel_size=(7, 7) stride=(2, 2) padding=(3, 3) dilation=(1, 1) groups=1 bias=0 )
(bn1) BatchNorm2d( num_features=64 eps=0.000010 momentum=0.100000 )
(relu) ReLU
(maxpool) MaxPool2d( kernel_size=(3, 3) stride=(2, 2) padding=(1, 1) )
(layer1) Sequential (
(0) Bottleneck (
(conv1) Conv2d( in_channels=64 out_channels=64 kernel_size=(1, 1) stride=(1, 1) padding=(0, 0) dilation=(1, 1) groups=1 bias=0 )
(bn1) BatchNorm2d( num_features=64 eps=0.000010 momentum=0.100000 )
(conv2) Conv2d( in_channels=64 out_channels=64 kernel_size=(3, 3) stride=(1, 1) padding=(1, 1) dilation=(1, 1) groups=1 bias=0 )
(bn2) BatchNorm2d( num_features=64 eps=0.000010 momentum=0.100000 )
(conv3) Conv2d( in_channels=64 out_channels=256 kernel_size=(1, 1) stride=(1, 1) padding=(0, 0) dilation=(1, 1) groups=1 bias=0 )
(bn3) BatchNorm2d( num_features=256 eps=0.000010 momentum=0.100000 )
(downsample) Sequential (
(0) Conv2d( in_channels=64 out_channels=256 kernel_size=(1, 1) stride=(1, 1) padding=(0, 0) dilation=(1, 1) groups=1 bias=0 )
(1) BatchNorm2d( num_features=256 eps=0.000010 momentum=0.100000 )
)
)
(1) Bottleneck (
(conv1) Conv2d( in_channels=256 out_channels=64 kernel_size=(1, 1) stride=(1, 1) padding=(0, 0) dilation=(1, 1) groups=1 bias=0 )
(bn1) BatchNorm2d( num_features=64 eps=0.000010 momentum=0.100000 )
(conv2) Conv2d( in_channels=64 out_channels=64 kernel_size=(3, 3) stride=(1, 1) padding=(1, 1) dilation=(1, 1) groups=1 bias=0 )
(bn2) BatchNorm2d( num_features=64 eps=0.000010 momentum=0.100000 )
(conv3) Conv2d( in_channels=256 out_channels=256 kernel_size=(1, 1) stride=(1, 1) padding=(0, 0) dilation=(1, 1) groups=1 bias=0 )
(bn3) BatchNorm2d( num_features=256 eps=0.000010 momentum=0.100000 )
)
(2) Bottleneck (
(conv1) Conv2d( in_channels=256 out_channels=64 kernel_size=(1, 1) stride=(1, 1) padding=(0, 0) dilation=(1, 1) groups=1 bias=0 )
(bn1) BatchNorm2d( num_features=64 eps=0.000010 momentum=0.100000 )
(conv2) Conv2d( in_channels=64 out_channels=64 kernel_size=(3, 3) stride=(1, 1) padding=(1, 1) dilation=(1, 1) groups=1 bias=0 )
(bn2) BatchNorm2d( num_features=64 eps=0.000010 momentum=0.100000 )
(conv3) Conv2d( in_channels=256 out_channels=256 kernel_size=(1, 1) stride=(1, 1) padding=(0, 0) dilation=(1, 1) groups=1 bias=0 )
(bn3) BatchNorm2d( num_features=256 eps=0.000010 momentum=0.100000 )
)
)
/* .... */
(avgpool) AvgPool2d( kernel_size=(7, 7) stride=(1, 1) padding=(0, 0) )
(fc) nn.Linear( in_features=2048 out_features=1000 bias=1 )
)
Inspect a Tensor
auto net = torch::resnet50_imagenet();
net->load_weights("../resnet50_imagenet.h5");
net->cuda();
Tensor dummy_input = CUDA(kFloat).ones({1, 3, 224, 224});
auto result = net->forward(dummy_input);
cout << result << endl;
Columns 1 to 10-0.3081 0.0798 -1.1900 -1.4837 -0.5136 0.3683 -2.1639 -0.8705 -1.8812 -0.1608
Columns 11 to 20 0.2168 -0.9283 -1.2954 -1.0791 -1.4445 -0.8946 -0.0959 -1.3099 -1.2062 -1.2327
Columns 21 to 30-1.0658 0.9427 0.5739 -0.2746 -1.0189 -0.3583 -0.1826 0.2785 0.2209 -0.3340
Columns 31 to 40-1.9800 -0.5552 -1.0804 -0.8056 -0.0005 -1.8402 -0.7979 -1.4823 1.3657 -0.8970
/* .... */
Columns 961 to 970-0.0557 -0.7405 -0.5501 -1.7207 -0.7043 -1.0925 1.5812 -0.1215 0.8915 0.9794
Columns 971 to 980-1.1422 -0.1235 -0.5999 -2.1338 -0.0775 -0.8374 -0.2350 -0.0104 -0.0416 -1.0296
Columns 981 to 990-0.2914 -0.2242 -0.8063 -0.7818 -0.2714 0.0002 -1.2355 0.1238 0.0183 -0.6904
Columns 991 to 1000 0.5216 -1.8008 -1.7826 -1.2970 -1.6565 -1.3306 -0.6564 -1.6531 0.1178 0.2436
[ CUDAFloatTensor{1,1000} ]
Create a network
auto new_net = std::make_shared<torch::Sequential>();
new_net->add(std::make_shared<torch::Conv2d>(3, 10, 3, 3));
new_net->add(std::make_shared<torch::BatchNorm2d>(10));
new_net->add(std::make_shared<torch::ReLU>());
new_net->add(std::make_shared<torch::Linear>(10, 3));
Implemented layers
So far, these layers are available which respect the Pytorch's layers semantics which can be found here.
- nn.Sequential
- nn.Conv2d
- nn.MaxPool2d
- nn.AvgPool2d
- nn.ReLU
- nn.Linear
- nn.SoftMax
- nn.BatchNorm2d
- nn.Dropout2d
- nn.DataParallel
- nn.AdaptiveMaxPool2d
- nn.Sigmoid and others.
Implemented models
Some convered models are provided for ease of access. Other models can be easily converted.
Imagenet models
All models were converted from pytorch/vision and checked for correctness.
- Resnet-18
- Resnet-34
- Resnet-50
- Resnet-101
- Resnet-150
- Resnet-152
- All VGG models
- All Densenet models
- All Inception models
- All squeezenet models
- Alexnet
Segmentation PASCAL VOC
All models were converted from this repository and checked for correctness.
- Resnet-18-8S
- Resnet-34-8S
- Resnet-50-8S
- Resnet-101-8S
- Resnet-152-8S
- FCN-32s
- FCN-16s
- FCN-8s
Demos
We created a couple of demos where we grab frames using opencv and classify or segment them.
Here you can see and example of real-time segmentation:
Installation
ATen
ATen is a C++ 11 library that wraps a powerfull C Tensor library with implementation of numpy-like operations (CPU/CUDA/SPARSE/CUDA-SPARSE backends). Follow these steps to install it:
- Make sure you have dependencies of
ATen
installed. git clone --recursive https://github.com/warmspringwinds/pytorch-cpp
cd pytorch-cpp/ATen;mkdir build;cd build;cmake-gui ..
and specifyCUDA_TOOLKIT_ROOT_DIR
.make
or bettermake -j7
(replace7
with a number of cores that you have).cd ../../
-- returns you back to the root directory (necessary for the next step).
HDF5
We use HDF5
to be able to easily convert weigths between Pytorch
and Pytorch-C++
.
wget https://support.hdfgroup.org/ftp/HDF5/current18/src/CMake-hdf5-1.8.20.tar.gz; tar xvzf CMake-hdf5-1.8.19.tar.gz
cd CMake-hdf5-1.8.19; ./build-unix.sh
cd ../
-- return back.
Additional information: HDF5
gets updated from time to time and there is a good chance that my link might be outdated.
If it's the case, grab the latest version from the official website.
Also, after you do this don't forget to update the CMakelists.txt
file with the new hdf5 folder name.
Opencv
We need OpenCV
for a couple of examples which grab frames from a web camera.
It is not a dependency and can be removed if necessary.
This was tested on Ubuntu-16
and might need some changes on a different system.
sudo apt-get install libopencv-dev python-opencv
Pytorch-C++
Pytorch-C++
is a library on top of ATen
that provides a Pytorch-like
interface for building neural networks and inference (so far only forward pass is supported)
inspired by cunnproduction library. To install it, follow
these steps:
mkdir build; cd build; cmake-gui ..
and specifyCUDA_TOOLKIT_ROOT_DIR
.make
cd ../
-- return back
Problems with the build
It was noticed that if you have anaconda installed and your PATH
variable is modified to include
its folder, it can lead to failed buid (caused by the fact that anaconda uses different version of gcc
).
To solve this problem, remove the path to anaconda from PATH
for the time of the build.
If you face any problems or some steps are not clear, please open an issue. Note: every time you enter the cmake-gui
press configure
first, then specify your CUDA
path and then press generate
, after that you can build.
About
If you used the code for your research, please, cite the paper:
@article{pakhomov2017deep,
title={Deep Residual Learning for Instrument Segmentation in Robotic Surgery},
author={Pakhomov, Daniil and Premachandran, Vittal and Allan, Max and Azizian, Mahdi and Navab, Nassir},
journal={arXiv preprint arXiv:1703.08580},
year={2017}
}
During implementation, some preliminary experiments and notes were reported:
- Converting Image Classification network into FCN
- Performing upsampling using transposed convolution
- Conditional Random Fields for Refining of Segmentation and Coarseness of FCN-32s model segmentations
- TF-records usage
Contributors
- Daniil Pakhomov