face_recognition

The world's simplest facial recognition api for Python and the command line

ageitgey
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Python

Face Recognition

You can also read a translated version of this file in Chinese 简体中文版 or in Korean 한국어 or in Japanese 日本語.

Recognize and manipulate faces from Python or from the command line with
the world’s simplest face recognition library.

Built using dlib’s state-of-the-art face recognition
built with deep learning. The model has an accuracy of 99.38% on the
Labeled Faces in the Wild benchmark.

This also provides a simple face_recognition command line tool that lets
you do face recognition on a folder of images from the command line!

PyPI
Build Status
Documentation Status

Features

Find faces in pictures

Find all the faces that appear in a picture:

import face_recognition
image = face_recognition.load_image_file("your_file.jpg")
face_locations = face_recognition.face_locations(image)

Find and manipulate facial features in pictures

Get the locations and outlines of each person’s eyes, nose, mouth and chin.

import face_recognition
image = face_recognition.load_image_file("your_file.jpg")
face_landmarks_list = face_recognition.face_landmarks(image)

Finding facial features is super useful for lots of important stuff. But you can also use it for really stupid stuff
like applying digital make-up (think ‘Meitu’):

Identify faces in pictures

Recognize who appears in each photo.

import face_recognition
known_image = face_recognition.load_image_file("biden.jpg")
unknown_image = face_recognition.load_image_file("unknown.jpg")

biden_encoding = face_recognition.face_encodings(known_image)[0]
unknown_encoding = face_recognition.face_encodings(unknown_image)[0]

results = face_recognition.compare_faces([biden_encoding], unknown_encoding)

You can even use this library with other Python libraries to do real-time face recognition:

See this example for the code.

Online Demos

User-contributed shared Jupyter notebook demo (not officially supported): Deepnote

Installation

Requirements

  • Python 3.3+ or Python 2.7
  • macOS or Linux (Windows not officially supported, but might work)

Installation Options:

Installing on Mac or Linux

First, make sure you have dlib already installed with Python bindings:

Then, make sure you have cmake installed:

brew install cmake

Finally, install this module from pypi using pip3 (or pip2 for Python 2):

pip3 install face_recognition

Alternatively, you can try this library with Docker, see this section.

If you are having trouble with installation, you can also try out a
pre-configured VM.

Installing on an Nvidia Jetson Nano board

  • Jetson Nano installation instructions
    • Please follow the instructions in the article carefully. There is current a bug in the CUDA libraries on the Jetson Nano that will cause this library to fail silently if you don’t follow the instructions in the article to comment out a line in dlib and recompile it.

Installing on Raspberry Pi 2+

Installing on FreeBSD

pkg install graphics/py-face_recognition

Installing on Windows

While Windows isn’t officially supported, helpful users have posted instructions on how to install this library:

Installing a pre-configured Virtual Machine image

Usage

Command-Line Interface

When you install face_recognition, you get two simple command-line
programs:

  • face_recognition - Recognize faces in a photograph or folder full for
    photographs.
  • face_detection - Find faces in a photograph or folder full for photographs.

face_recognition command line tool

The face_recognition command lets you recognize faces in a photograph or
folder full for photographs.

First, you need to provide a folder with one picture of each person you
already know. There should be one image file for each person with the
files named according to who is in the picture:

known

Next, you need a second folder with the files you want to identify:

unknown

Then in you simply run the command face_recognition, passing in
the folder of known people and the folder (or single image) with unknown
people and it tells you who is in each image:

$ face_recognition ./pictures_of_people_i_know/ ./unknown_pictures/

/unknown_pictures/unknown.jpg,Barack Obama
/face_recognition_test/unknown_pictures/unknown.jpg,unknown_person

There’s one line in the output for each face. The data is comma-separated
with the filename and the name of the person found.

An unknown_person is a face in the image that didn’t match anyone in
your folder of known people.

face_detection command line tool

The face_detection command lets you find the location (pixel coordinatates)
of any faces in an image.

Just run the command face_detection, passing in a folder of images
to check (or a single image):

$ face_detection  ./folder_with_pictures/

examples/image1.jpg,65,215,169,112
examples/image2.jpg,62,394,211,244
examples/image2.jpg,95,941,244,792

It prints one line for each face that was detected. The coordinates
reported are the top, right, bottom and left coordinates of the face (in pixels).

Adjusting Tolerance / Sensitivity

If you are getting multiple matches for the same person, it might be that
the people in your photos look very similar and a lower tolerance value
is needed to make face comparisons more strict.

You can do that with the --tolerance parameter. The default tolerance
value is 0.6 and lower numbers make face comparisons more strict:

$ face_recognition --tolerance 0.54 ./pictures_of_people_i_know/ ./unknown_pictures/

/unknown_pictures/unknown.jpg,Barack Obama
/face_recognition_test/unknown_pictures/unknown.jpg,unknown_person

If you want to see the face distance calculated for each match in order
to adjust the tolerance setting, you can use --show-distance true:

$ face_recognition --show-distance true ./pictures_of_people_i_know/ ./unknown_pictures/

/unknown_pictures/unknown.jpg,Barack Obama,0.378542298956785
/face_recognition_test/unknown_pictures/unknown.jpg,unknown_person,None
More Examples

If you simply want to know the names of the people in each photograph but don’t
care about file names, you could do this:

$ face_recognition ./pictures_of_people_i_know/ ./unknown_pictures/ | cut -d ',' -f2

Barack Obama
unknown_person
Speeding up Face Recognition

Face recognition can be done in parallel if you have a computer with
multiple CPU cores. For example, if your system has 4 CPU cores, you can
process about 4 times as many images in the same amount of time by using
all your CPU cores in parallel.

If you are using Python 3.4 or newer, pass in a --cpus <number_of_cpu_cores_to_use> parameter:

$ face_recognition --cpus 4 ./pictures_of_people_i_know/ ./unknown_pictures/

You can also pass in --cpus -1 to use all CPU cores in your system.

Python Module

You can import the face_recognition module and then easily manipulate
faces with just a couple of lines of code. It’s super easy!

API Docs: https://face-recognition.readthedocs.io.

Automatically find all the faces in an image
import face_recognition

image = face_recognition.load_image_file("my_picture.jpg")
face_locations = face_recognition.face_locations(image)

# face_locations is now an array listing the co-ordinates of each face!

See this example
to try it out.

You can also opt-in to a somewhat more accurate deep-learning-based face detection model.

Note: GPU acceleration (via NVidia’s CUDA library) is required for good
performance with this model. You’ll also want to enable CUDA support
when compliling dlib.

import face_recognition

image = face_recognition.load_image_file("my_picture.jpg")
face_locations = face_recognition.face_locations(image, model="cnn")

# face_locations is now an array listing the co-ordinates of each face!

See this example
to try it out.

If you have a lot of images and a GPU, you can also
find faces in batches.

Automatically locate the facial features of a person in an image
import face_recognition

image = face_recognition.load_image_file("my_picture.jpg")
face_landmarks_list = face_recognition.face_landmarks(image)

# face_landmarks_list is now an array with the locations of each facial feature in each face.
# face_landmarks_list[0]['left_eye'] would be the location and outline of the first person's left eye.

See this example
to try it out.

Recognize faces in images and identify who they are
import face_recognition

picture_of_me = face_recognition.load_image_file("me.jpg")
my_face_encoding = face_recognition.face_encodings(picture_of_me)[0]

# my_face_encoding now contains a universal 'encoding' of my facial features that can be compared to any other picture of a face!

unknown_picture = face_recognition.load_image_file("unknown.jpg")
unknown_face_encoding = face_recognition.face_encodings(unknown_picture)[0]

# Now we can see the two face encodings are of the same person with `compare_faces`!

results = face_recognition.compare_faces([my_face_encoding], unknown_face_encoding)

if results[0] == True:
    print("It's a picture of me!")
else:
    print("It's not a picture of me!")

See this example
to try it out.

Python Code Examples

All the examples are available here.

Face Detection

Facial Features

Facial Recognition

Creating a Standalone Executable

If you want to create a standalone executable that can run without the need to install python or face_recognition, you can use PyInstaller. However, it requires some custom configuration to work with this library. See this issue for how to do it.

Articles and Guides that cover face_recognition

How Face Recognition Works

If you want to learn how face location and recognition work instead of
depending on a black box library, read my article.

Caveats

  • The face recognition model is trained on adults and does not work very well on children. It tends to mix
    up children quite easy using the default comparison threshold of 0.6.
  • Accuracy may vary between ethnic groups. Please see this wiki page for more details.

Deployment to Cloud Hosts (Heroku, AWS, etc)

Since face_recognition depends on dlib which is written in C++, it can be tricky to deploy an app
using it to a cloud hosting provider like Heroku or AWS.

To make things easier, there’s an example Dockerfile in this repo that shows how to run an app built with
face_recognition in a Docker container. With that, you should be able to deploy
to any service that supports Docker images.

You can try the Docker image locally by running: docker-compose up --build

There are also several prebuilt Docker images.

Linux users with a GPU (drivers >= 384.81) and Nvidia-Docker installed can run the example on the GPU: Open the docker-compose.yml file and uncomment the dockerfile: Dockerfile.gpu and runtime: nvidia lines.

Having problems?

If you run into problems, please read the Common Errors section of the wiki before filing a github issue.

Thanks

  • Many, many thanks to Davis King (@nulhom)
    for creating dlib and for providing the trained facial feature detection and face encoding models
    used in this library. For more information on the ResNet that powers the face encodings, check out
    his blog post.
  • Thanks to everyone who works on all the awesome Python data science libraries like numpy, scipy, scikit-image,
    pillow, etc, etc that makes this kind of stuff so easy and fun in Python.
  • Thanks to Cookiecutter and the
    audreyr/cookiecutter-pypackage project template
    for making Python project packaging way more tolerable.