This algorithm can detect the faces from picture and then align them.

**Dowload model parameters:**

You should dowload the [model parameters](http://dlib.net/files/shape_predictor_68_face_landmarks.dat.bz2)

from dlib, decompress and move to `./dat`

**Installation:**

$ pip install -r requirements.txt

$ python3 main.py [pic1, pic2...]

After the script finished, you will get some faces picture in the same

directory.

import numpy as np

import os.path as osp

import sys

import cv2

import dlib

OUT_SIZE = (224, 224)

LEFT_EYE_RANGE = (36, 42)

RIGHT_EYE_RABGE = (42, 48)

LEFT_EYE_POS = (0.35, 0.3815)

DAT_PATH = "./dat/shape_predictor_68_face_landmarks.dat"

def main(files):

detector = dlib.get_frontal_face_detector()

sp = dlib.shape_predictor(DAT_PATH)

for file in files:

img = cv2.imread(file, cv2.IMREAD_ANYCOLOR)

img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)

faces = detect_align_faces(detector, sp, img)

for (idx, face) in enumerate(faces):

face = cv2.cvtColor(face, cv2.COLOR_RGB2BGR)

filename, ext = osp.splitext(file)

filename += '_face_{:03}'.format(idx) + ext

cv2.imwrite(filename, face)

def detect_align_faces(detector, sp, img):

faces = detector(img, 1)

res = []

for face in faces:

shape = sp(img, face)

left, right = shape_to_pos(shape)

left_center = np.mean(left, axis=0)

right_center = np.mean(right, axis=0)

dx = right_center[0] - left_center[0]

dy = right_center[1] - left_center[1]

angle = np.degrees(np.arctan2(dy, dx))

dist = np.sqrt(dy ** 2 + dx ** 2)

out_dist = OUT_SIZE[0] * (1 - 2 * LEFT_EYE_POS[0])

scale = out_dist / dist

center = ((left_center + right_center) // 2).tolist()

mat = cv2.getRotationMatrix2D(center, angle, scale)

mat[0, 2] += (0.5 * OUT_SIZE[0] - center[0])

mat[1, 2] += (LEFT_EYE_POS[1] * OUT_SIZE[1] - center[1])

res_face = cv2.warpAffine(img, mat, OUT_SIZE, flags=cv2.INTER_CUBIC)

res.append(res_face)

return res

def shape_to_pos(shape):

parts = []

for p in shape.parts():

parts.append((p.x, p.y))

left = parts[LEFT_EYE_RANGE[0]: LEFT_EYE_RANGE[-1]]

right = parts[RIGHT_EYE_RABGE[0]: RIGHT_EYE_RABGE[-1]]

return (np.array(left), np.array(right))

if __name__ == '__main__':

main(sys.argv[1:])