Detect faces function

app.py

def detect_faces(image):
    faceCascade = cv2.CascadeClassifier("haarcascade_frontalface_default.xml")
    img = Image.open(StringIO(image))
    img_cv2 = cv2.cvtColor(np.array(img), cv2.COLOR_RGB2RGBA)
    gray = cv2.cvtColor(img_cv2, cv2.COLOR_RGBA2GRAY)

    faces = faceCascade.detectMultiScale(
        gray,
        scaleFactor=1.1,
        minNeighbors=5,
        minSize=(30, 30),
        flags=cv2.cv.CV_HAAR_SCALE_IMAGE
    )
    try:
        return faces.tolist()
    except:
        return []