1. import cv2
2. import numpy as np
3. import math
4.  
5. cap = cv2.VideoCapture(0)
6.  
7. while(cap.isOpened()):
8.     ret, img = cap.read()
9.     cv2.rectangle(img,(300,300),(100,100),(0,255,0),0)
10.     crop_img = img[100:300, 100:300]
11.     grey = cv2.cvtColor(crop_img, cv2.COLOR_BGR2GRAY)
12.     value = (37,37)
13.     blurred = cv2.GaussianBlur(grey, value, 0)
14.     _, thresh1 = cv2.threshold(blurred, 127, 255,
15.                                cv2.THRESH_BINARY_INV+cv2.THRESH_OTSU)
16.     #cv2.imshow('Thresholded', thresh1)
17.     #print cv2.findContours(thresh1.copy(),cv2.RETR_TREE,cv2.CHAIN_APPROX_NONE)
18.     _, contours, hierarchy = cv2.findContours(thresh1.copy(),cv2.RETR_TREE,cv2.CHAIN_APPROX_NONE)
19.  
20.     max_area = -1
21.     print len(contours)
22.     for i in range(len(contours)):
23.         cnt=contours[i]
24.         area = cv2.contourArea(cnt)
25.         if(area>max_area):
26.             max_area=area
27.             ci=i
28.     cnt=contours[ci]
29.     x,y,w,h = cv2.boundingRect(cnt)
30.     cv2.rectangle(crop_img,(x,y),(x+w,y+h),(0,0,255),0)
31.     hull = cv2.convexHull(cnt)
32.     drawing = np.zeros(crop_img.shape,np.uint8)
33.     cv2.drawContours(drawing,[cnt],0,(0,255,0),0)
34.     cv2.drawContours(drawing,[hull],0,(0,0,255),0)
35.     hull = cv2.convexHull(cnt,returnPoints = False)
36.     defects = cv2.convexityDefects(cnt,hull)
37.     count_defects = 0
38.     cv2.drawContours(thresh1, contours, -1, (0,255,0), 3)
39.     for i in range(defects.shape[0]):
40.         s,e,f,d = defects[i,0]
41.         start = tuple(cnt[s][0])
42.         end = tuple(cnt[e][0])
43.         far = tuple(cnt[f][0])
44.         a = math.sqrt((end[0] - start[0])**2 + (end[1] - start[1])**2)
45.         b = math.sqrt((far[0] - start[0])**2 + (far[1] - start[1])**2)
46.         c = math.sqrt((end[0] - far[0])**2 + (end[1] - far[1])**2)
47.         angle = math.acos((b**2 + c**2 - a**2)/(2*b*c)) * 57
48.         if angle <= 90:
49.             count_defects += 1
50.             cv2.circle(crop_img,far,1,[0,0,255],-1)
51.         dist = cv2.pointPolygonTest(cnt,far,True)
52.         cv2.line(crop_img,start,end,[0,255,0],2)
53.         cv2.circle(crop_img,far,5,[0,0,255],-1)
54.  
55.     if count_defects>3:
56.         cv2.putText(img,"ABIERTA", (50,50), cv2.FONT_HERSHEY_SIMPLEX, 2, 4)
57.     else:
58.         cv2.putText(img,"CERRADA", (50,50), cv2.FONT_HERSHEY_SIMPLEX, 2, 4)
59.  
60.     cv2.imshow('drawing', drawing)
61.     cv2.imshow('end', crop_img)
62.     cv2.imshow('Gesture', img)
63.  
64.     all_img = np.hstack((drawing, crop_img))
65.     cv2.imshow('Contours', all_img)
66.     k = cv2.waitKey(10)
67.     if k == 27:
68.         cap.release()
69.         break