Snake图像分割

import matplotlib.pylab as pylab
from skimage.filters import gaussian
from skimage.segmentation import active_contour
img=cv2.imread('C:/Users/xpp/Desktop/Lena.png')#原始图像
gray=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)#将彩色图片转换为灰度图片
s=np.linspace(0,2*np.pi,400)#构造圆
x=260+100*np.cos(s)
y=240+100*np.sin(s)
init=np.array([x,y]).T#构造Snake
i=1
pylab.figure(figsize=(20,20))
for max_it in [20, 30, 50, 100]:
    snake=active_contour(gaussian(gray,3),init,alpha=0.015,beta=10,gamma=0.001,max_iterations=max_it)#Snake图像分割
    pylab.subplot(2,2,i)
    pylab.imshow(img)
    pylab.plot(init[:,0],init[:,1],'--b',lw=3)
    pylab.plot(snake[:,0],snake[:,1],'-r',lw=3)
    pylab.axis('off')
    pylab.title('max_iteration='+str(max_it),size=20)
    i+=1
    pylab.tight_layout()
    pylab.show()