Replace openCV face detection with MTCNN algorithm - opencv

Question

I am using openCV for face detection. Sometimes, openCV makes an issue to detect faces. the function name is
def detectFace(img_path):
img = functions.detectFace(img_path)[0] #detectFace returns (1, 224, 224, 3)
return img[:, :, ::-1] #bgr to rgb
I want above output from MTCNN algorithm
detectFace function code
def detectFace(img, target_size=(224, 224), grayscale = False, enforce_detection = True):
img_path = ""
img = "/media/khawar/HDD_Khawar/Projects/" + img
print(img)
#-----------------------
exact_image = False
if type(img).__module__ == np.__name__:
exact_image = True
base64_img = False
if len(img) > 11 and img[0:11] == "data:image/":
base64_img = True
#-----------------------
opencv_path = get_opencv_path()
face_detector_path = opencv_path+"haarcascade_frontalface_default.xml"
eye_detector_path = opencv_path+"haarcascade_eye.xml"
if os.path.isfile(face_detector_path) != True:
raise ValueError("Confirm that opencv is installed on your environment! Expected path ",face_detector_path," violated.")
#--------------------------------
face_detector = cv2.CascadeClassifier(face_detector_path)
eye_detector = cv2.CascadeClassifier(eye_detector_path)
if base64_img == True:
img = loadBase64Img(img)
elif exact_image != True: #image path passed as input
if os.path.isfile(img) != True:
raise ValueError("Confirm that ",img," exists")
img = cv2.imread(img)
img_raw = img.copy()
#--------------------------------
faces = []
try:
faces = face_detector.detectMultiScale(img, 1.3, 5)
except:
pass
#print("found faces in ",image_path," is ",len(faces))
if len(faces) > 0:
print(faces[0])
x,y,w,h = faces[0]
detected_face = img[int(y):int(y+h), int(x):int(x+w)]
detected_face_gray = cv2.cvtColor(detected_face, cv2.COLOR_BGR2GRAY)
#---------------------------
#face alignment
eyes = eye_detector.detectMultiScale(detected_face_gray)
if len(eyes) >= 2:
#find the largest 2 eye
base_eyes = eyes[:, 2]
items = []
for i in range(0, len(base_eyes)):
item = (base_eyes[i], i)
items.append(item)
df = pd.DataFrame(items, columns = ["length", "idx"]).sort_values(by=['length'], ascending=False)
eyes = eyes[df.idx.values[0:2]]
#-----------------------
#decide left and right eye
eye_1 = eyes[0]; eye_2 = eyes[1]
if eye_1[0] < eye_2[0]:
left_eye = eye_1
right_eye = eye_2
else:
left_eye = eye_2
right_eye = eye_1
#-----------------------
#find center of eyes
left_eye_center = (int(left_eye[0] + (left_eye[2] / 2)), int(left_eye[1] + (left_eye[3] / 2)))
left_eye_x = left_eye_center[0]; left_eye_y = left_eye_center[1]
right_eye_center = (int(right_eye[0] + (right_eye[2]/2)), int(right_eye[1] + (right_eye[3]/2)))
right_eye_x = right_eye_center[0]; right_eye_y = right_eye_center[1]
#-----------------------
#find rotation direction
if left_eye_y > right_eye_y:
point_3rd = (right_eye_x, left_eye_y)
direction = -1 #rotate same direction to clock
else:
point_3rd = (left_eye_x, right_eye_y)
direction = 1 #rotate inverse direction of clock
#-----------------------
#find length of triangle edges
a = distance(left_eye_center, point_3rd)
b = distance(right_eye_center, point_3rd)
c = distance(right_eye_center, left_eye_center)
#-----------------------
#apply cosine rule
if b != 0 and c != 0: #this multiplication causes division by zero in cos_a calculation
cos_a = (b*b + c*c - a*a)/(2*b*c)
angle = np.arccos(cos_a) #angle in radian
angle = (angle * 180) / math.pi #radian to degree
#-----------------------
#rotate base image
if direction == -1:
angle = 90 - angle
img = Image.fromarray(img_raw)
img = np.array(img.rotate(direction * angle))
#you recover the base image and face detection disappeared. apply again.
faces = face_detector.detectMultiScale(img, 1.3, 5)
if len(faces) > 0:
x,y,w,h = faces[0]
detected_face = img[int(y):int(y+h), int(x):int(x+w)]
#-----------------------
#face alignment block end
#---------------------------
#face alignment block needs colorful images. that's why, converting to gray scale logic moved to here.
if grayscale == True:
detected_face = cv2.cvtColor(detected_face, cv2.COLOR_BGR2GRAY)
detected_face = cv2.resize(detected_face, target_size)
img_pixels = image.img_to_array(detected_face)
img_pixels = np.expand_dims(img_pixels, axis = 0)
#normalize input in [0, 1]
img_pixels /= 255
return img_pixels
else:
if (exact_image == True) or (enforce_detection != True):
if grayscale == True:
img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
img = cv2.resize(img, target_size)
img_pixels = image.img_to_array(img)
img_pixels = np.expand_dims(img_pixels, axis = 0)
img_pixels /= 255
return img_pixels
else:
print(img)
raise ValueError("Face could not be detected. Please confirm that the picture is a face photo or consider to set enforce_detection param to False.")

Answer 1

Try this out .
import mtcnn
import matplotlib.pyplot as plt
# load image from file
filename = "glediston-bastos-ZtmmR9D_2tA-unsplash.jpg"
pixels = plt.imread(filename)
print("Shape of image/array:",pixels.shape)
imgplot = plt.imshow(pixels)
plt.show()
# draw an image with detected objects
def draw_facebox(filename, result_list):
# load the image
data = plt.imread(filename)
# plot the image
plt.imshow(data)
# get the context for drawing boxes
ax = plt.gca()
# plot each box
for result in result_list:
# get coordinates
x, y, width, height = result['box']
# create the shape
rect = plt.Rectangle((x, y), width, height, fill=False, color='green')
# draw the box
ax.add_patch(rect)
# show the plot
plt.show()
# filename = 'test1.jpg' # filename is defined above, otherwise uncomment
# load image from file
# pixels = plt.imread(filename) # defined above, otherwise uncomment
# detector is defined above, otherwise uncomment
#detector = mtcnn.MTCNN()
# detect faces in the image
faces = detector.detect_faces(pixels)
# display faces on the original image
draw_facebox(filename, faces)
# draw the dots
for key, value in result['keypoints'].items():
# create and draw dot
dot = plt.Circle(value, radius=20, color='orange')
ax.add_patch(dot)

Answer 2

You are using detectFace function within deepface? It currently wraps opencv, ssd, dlib and mtcnn to detect and align faces.
def detectFace(img_path):
backends = ['opencv', 'ssd', 'dlib', 'mtcnn']
img = functions.detectFace(img_path, detector_backend = backends[3])[0] #detectFace returns (1, 224, 224, 3)
return img[:, :, ::-1] #bgr to rgb
The result of the detectFace function is detected and aligned with mtcnn now.
Besides, you can run face recognition with mtcnn backend as well.
from deepface import DeepFace
obj = DeepFace.verify("img1.jpg", "img2.jpg", detector_backend = 'mtcnn')