Face Recognition Using Pytorch

System	Python
Linux	3.5, 3.6, 3.7
macOS	3.6, 3.7
Windows	3.5, 3.6, 3.7

This is a repository for Inception Resnet (V1) models in pytorch, pretrained on VGGFace2 and CASIA-Webface.

Pytorch model weights were initialized using parameters ported from David Sandberg's tensorflow facenet repo.

Also included in this repo is an efficient pytorch implementation of MTCNN for face detection prior to inference. These models are also pretrained.

Quick start

Either install using pip:

pip install facenet-pytorch

or clone this repo, removing the '-' to allow python imports:

git clone https://github.com/timesler/facenet-pytorch.git facenet_pytorch

In python, import the module:

from facenet_pytorch import MTCNN, InceptionResnetV1

If required, create a face detection pipeline using MTCNN:

mtcnn = MTCNN(image_size=<image_size>, margin=<margin>)

Create an inception resnet (in eval mode):

resnet = InceptionResnetV1(pretrained='vggface2').eval()

Process an image:

from PIL import Image

img = Image.open(<image path>)

# Get cropped and prewhitened image tensor
img_cropped = mtcnn(img, save_path=<optional save path>)

# Calculate embedding (unsqueeze to add batch dimension)
img_embedding = resnet(img_cropped.unsqueeze(0))

# Or, if using for VGGFace2 classification
resnet.classify = True
img_probs = resnet(img_cropped.unsqueeze(0))

See help(MTCNN) and help(InceptionResnetV1) for usage and implementation details.

Pretrained models

See: models/inception_resnet_v1.py

The following models have been ported to pytorch (with links to download pytorch state_dict's):

Model name	LFW accuracy (as listed here)	Training dataset
20180408-102900 (111MB)	0.9905	CASIA-Webface
20180402-114759 (107MB)	0.9965	VGGFace2

There is no need to manually download the pretrained state_dict's; they are downloaded automatically on model instantiation and cached for future use in the torch cache. To use an Inception Resnet (V1) model for facial recognition/identification in pytorch, use:

from facenet_pytorch import InceptionResnetV1

# For a model pretrained on VGGFace2
model = InceptionResnetV1(pretrained='vggface2').eval()

# For a model pretrained on CASIA-Webface
model = InceptionResnetV1(pretrained='casia-webface').eval()

# For an untrained model
model = InceptionResnetV1().eval()

# For an untrained 1001-class classifier
model = InceptionResnetV1(classify=True, num_classes=1001).eval()

Both pretrained models were trained on 160x160 px images, so will perform best if applied to images resized to this shape. For best results, images should also be cropped to the face using MTCNN (see below).

By default, the above models will return 512-dimensional embeddings of images. To enable classification instead, either pass classify=True to the model constructor, or you can set the object attribute afterwards with model.classify = True. For VGGFace2, the pretrained model will output probability vectors of length 8631, and for CASIA-Webface probability vectors of length 10575.

Complete detection and recognition pipeline

Face recognition can be easily applied to raw images by first detecting faces using MTCNN before calculating embedding or probabilities using an Inception Resnet model.

The example code at examples/infer.ipynb provides a complete example pipeline utilizing datasets, dataloaders, and optional GPU processing.

Face tracking in video streams

MTCNN can be used to build a face tracking system (using the MTCNN.detect() method). A full face tracking example can be found at examples/face_tracking.ipynb.

Use this repo in your own git project

To use pretrained MTCNN and Inception Resnet V1 models in your own git repo, I recommend first adding this repo as a submodule. Note that the dash ('-') in the repo name should be removed when cloning as a submodule as it will break python when importing:

git submodule add https://github.com/timesler/facenet-pytorch.git facenet_pytorch

Alternatively, the code can be installed as a package using pip:

pip install facenet-pytorch

Models can then be instantiated simply with the following:

from facenet_pytorch import MTCNN, InceptionResnetV1

mtcnn = MTCNN()
resnet = InceptionResnetV1(pretrained='vggface2').eval()

Conversion of parameters from Tensorflow to Pytorch

See: models/utils/tensorflow2pytorch.py

Note that this functionality is not needed to use the models in this repo, which depend only on the saved pytorch state_dict's.

Following instantiation of the pytorch model, each layer's weights were loaded from equivalent layers in the pretrained tensorflow models from davidsandberg/facenet.

The equivalence of the outputs from the original tensorflow models and the pytorch-ported models have been tested and are identical:

>>> compare_model_outputs(mdl, sess, torch.randn(5, 160, 160, 3).detach())

Passing test data through TF model

tensor([[-0.0142,  0.0615,  0.0057,  ...,  0.0497,  0.0375, -0.0838],
        [-0.0139,  0.0611,  0.0054,  ...,  0.0472,  0.0343, -0.0850],
        [-0.0238,  0.0619,  0.0124,  ...,  0.0598,  0.0334, -0.0852],
        [-0.0089,  0.0548,  0.0032,  ...,  0.0506,  0.0337, -0.0881],
        [-0.0173,  0.0630, -0.0042,  ...,  0.0487,  0.0295, -0.0791]])

Passing test data through PT model

tensor([[-0.0142,  0.0615,  0.0057,  ...,  0.0497,  0.0375, -0.0838],
        [-0.0139,  0.0611,  0.0054,  ...,  0.0472,  0.0343, -0.0850],
        [-0.0238,  0.0619,  0.0124,  ...,  0.0598,  0.0334, -0.0852],
        [-0.0089,  0.0548,  0.0032,  ...,  0.0506,  0.0337, -0.0881],
        [-0.0173,  0.0630, -0.0042,  ...,  0.0487,  0.0295, -0.0791]],
       grad_fn=<DivBackward0>)

Distance 1.2874517096861382e-06

In order to re-run the conversion of tensorflow parameters into the pytorch model, ensure you clone this repo with submodules, as the davidsandberg/facenet repo is included as a submodule and parts of it are required for the conversion.

References

David Sandberg's facenet repo: https://github.com/davidsandberg/facenet
F. Schroff, D. Kalenichenko, J. Philbin. FaceNet: A Unified Embedding for Face Recognition and Clustering, arXiv:1503.03832, 2015. PDF
Q. Cao, L. Shen, W. Xie, O. M. Parkhi, A. Zisserman. VGGFace2: A dataset for recognising face across pose and age, International Conference on Automatic Face and Gesture Recognition, 2018. PDF
D. Yi, Z. Lei, S. Liao and S. Z. Li. CASIAWebface: Learning Face Representation from Scratch, arXiv:1411.7923, 2014. PDF
K. Zhang, Z. Zhang, Z. Li and Y. Qiao. Joint Face Detection and Alignment Using Multitask Cascaded Convolutional Networks, IEEE Signal Processing Letters, 2016. PDF

casey-barr/facenet-pytorch