#-*- coding: utf-8 -*-
# import 進openCV的庫
import cv2

###調(diào)用電腦攝像頭檢測人臉并截圖

def CatchPICFromVideo(window_name, camera_idx, catch_pic_num, path_name):
 cv2.namedWindow(window_name)

 #視頻來源，可以來自一段已存好的視頻，也可以直接來自USB攝像頭
 cap = cv2.VideoCapture(camera_idx)

 #告訴OpenCV使用人臉識別分類器
 classfier = cv2.CascadeClassifier("haarcascade_frontalface_alt.xml")

 #識別出人臉后要畫的邊框的顏色，RGB格式, color是一個不可增刪的數(shù)組
 color = (0, 255, 0)

 num = 0
 while cap.isOpened():
  ok, frame = cap.read() #讀取一幀數(shù)據(jù)
  if not ok:
   break

  grey = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) #將當前楨圖像轉(zhuǎn)換成灰度圖像

  #人臉檢測，1.2和2分別為圖片縮放比例和需要檢測的有效點數(shù)
  faceRects = classfier.detectMultiScale(grey, scaleFactor = 1.2, minNeighbors = 3, minSize = (32, 32))
  if len(faceRects) > 0:   #大于0則檢測到人臉
   for faceRect in faceRects: #單獨框出每一張人臉
    x, y, w, h = faceRect

    #將當前幀保存為圖片
    img_name = "%s/%d.jpg" % (path_name, num)
    #print(img_name)
    image = frame[y - 10: y + h + 10, x - 10: x + w + 10]
    cv2.imwrite(img_name, image,[int(cv2.IMWRITE_PNG_COMPRESSION), 9])

    num += 1
    if num > (catch_pic_num): #如果超過指定最大保存數(shù)量退出循環(huán)
     break

    #畫出矩形框
    cv2.rectangle(frame, (x - 10, y - 10), (x + w + 10, y + h + 10), color, 2)

    #顯示當前捕捉到了多少人臉圖片了，這樣站在那里被拍攝時心里有個數(shù)，不用兩眼一抹黑傻等著
    font = cv2.FONT_HERSHEY_SIMPLEX
    cv2.putText(frame,'num:%d/100' % (num),(x + 30, y + 30), font, 1, (255,0,255),4)

    #超過指定最大保存數(shù)量結(jié)束程序
  if num > (catch_pic_num): break

  #顯示圖像
  cv2.imshow(window_name, frame)
  c = cv2.waitKey(10)
  if c & 0xFF == ord('q'):
   break

   #釋放攝像頭并銷毀所有窗口
 cap.release()
 cv2.destroyAllWindows()

if __name__ == '__main__':
 # 連續(xù)截100張圖像，存進image文件夾中
 CatchPICFromVideo("get face", 0, 99, "/image")