用OpenCV + dlib 制作“平均脸”
既然知道了原理,我们现在就要开始动手制作了。
再来回顾一下步骤,当我们要将N张人脸照片合称为一张平均脸的时候,我们首先要处理每一张照片:
【1】获取其中的68个脸部特征点,并以这些点为定点,剖分Delaunay 三角形,就如下图这样:
[Code-1] 首先要获得68个脸部特征点,这68个点定义了脸型、眉毛、眼睛、鼻子和嘴的轮廓。幸运的是,这么复杂的操作,我们用OpenCV,几行代码就搞定了!
detector = dlib.get_frontal_face_detector()
predictor = dlib.shape_predictor(predictor_path)
img = io.imread(image_file_path)
dets = detector(img, 1)
for k, d in enumerate(dets):
shape = predictor(img, d)
points = np.zeros((68, 2), dtype = int)
for i in range(0, 68):
points[i] = (int(shape.part(i).x), int(shape.part(i).y))
[Code-2] 接着剖分Delaunay 三角形,其中points就是68个面部特征点,rect是脸部所在的矩形:
def calculateDelaunayTriangles(rect, points):
subdiv = cv2.Subdiv2D(rect);
for p in points:
subdiv.insert((p[0], p[1]));
triangleList = subdiv.getTriangleList();
delaunayTri = []
for t in triangleList:
pt = []
pt.append((t[0], t[1]))
pt.append((t[2], t[3]))
pt.append((t[4], t[5]))
pt1 = (t[0], t[1])
pt2 = (t[2], t[3])
pt3 = (t[4], t[5])
if rectContains(rect, pt1) and rectContains(rect, pt2) and rectContains(rect, pt3):
ind = []