py + opencv 打造树莓派监控，场景有变化自动拍照上传到百度云
大家用树莓派来做监控，文章里面一般都是使用 fswebcam 或 motion。motion 非常强大，可以监测画面变化后保存成 mpeg 或 jpeg，还可以运行成 http 服务器模式。但是树莓派放在家里，从外面访问有时也会访问不了（比如 IP 变了等原因）。其实使用 Python + OpenCV 打造一个对运动画面能够进行简单判断的程序并不困难。下面的程序每个 0.5 秒做一下检测，如果画面有变化就保存下来，并且将其上传到百度的云存储中。为了保证隐私，上传之前还可以给照片做 AES 加密，只有知道密码才能查看照片的内容。不过，OpenCV 在树莓派上跑还是挺吃力的，CPU 基本保持在 6-70% 左右。
注册为百度开发者（http://developer.baidu.com/）就可以创建自己的百度云存储空间了。然后在云存储中新建一个 bucket，把代码中所有的 'homepics' 替换成你的 bucket 名称。
要运行这个程序，在树莓派上需要安装有 python2.7 和 PyCrypto、OpenCV、numpy、requests 模块。
在命令行运行：cv.py -d 0 -i /home/img -p qwerty123456qwerty123456 -u bcs:[app_key]:[sk]
如果没有 -p 参数照片就不加密，没有 -u 参数就不会存到百度云上。
另外，还做了一个 web 站点，把 bucket 中图片都列出来，用浏览器就可以直接查看：http://eaho.sinaapp.com/
#coding: cp936
import os, time, datetime, multiprocessing, urllib, base64, hashlib, hmac, argparse, tempfile
import cv2, numpy, requests
from Crypto.Cipher import AES
from Crypto.Util import Counter
class Bcs:
def __init__(self, ak, sk):
self.base_url = 'http://bcs.duapp.com'
self.ak = ak
self.sk = sk
self.MAX_FILE_SIZE = 250000
def getContent(self, method = 'GET', bucket = '', obj = '', time = None, ip = None, size = None):
content = 'Method=%s\n' % method
content += 'Bucket=%s\n' % bucket
content += 'Object=/%s\n' % obj
flag = 'MBO'
if time:
flag += 'T'
content += 'Time=%d\n' % time
if ip:
flag += 'I'
content += 'Ip=%s\n' % ip
if size:
flag += 'S'
content += 'Size=%d\n' % size
return flag, flag + '\n' + content
def getSignature(self, content):
return urllib.quote_plus(base64.encodestring(hmac.new(self.sk, content, hashlib.sha1).digest())[:-1])
def getUrl(self, flag, signature, bucket = '', obj = '', time = None, size = None, oparam = ''):
if obj:
bucket += '/%s' % obj
url = []
param = ''
if time:
url.append('time=%d' % time)
if size:
url.append('size=%d' % size)
if url:
param = '&' + '&'.join(url)
if oparam:
param += '&' + oparam
return '%s/%s?sign=%s:%s:%s%s' % (self.base_url, bucket, flag, self.ak, signature, param)
def upload(self, path, bucket):
name = os.path.split(path)
filename = name[1]
file_size = self.MAX_FILE_SIZE
timestamp = int(time.time() + 60)
flag, content = self.getContent(method = 'POST', bucket = bucket, obj = filename, time = timestamp, size = file_size)
signature = self.getSignature(content)
url = self.getUrl(flag, signature, bucket, filename, timestamp, file_size)
print self.postFile(url, path)
def upload2(self, filename, bucket, text):
file_size = self.MAX_FILE_SIZE
timestamp = int(time.time() + 60)
flag, content = self.getContent(method = 'POST', bucket = bucket, obj = filename, time = timestamp, size = file_size)
signature = self.getSignature(content)
url = self.getUrl(flag, signature, bucket, filename, timestamp, file_size)
print self.postFileContent(url, text)
def postFile(self, url, path):
f = open(path, 'rb')
files = {'file': f}
result = requests.post(url, files=files)
f.close()
return result.text
def postFileContent(self, url, content):
files = {'file': content}
result = requests.post(url, files=files)
return result.text
def listBucket(self):
flag, content = self.getContent(method = 'GET')
signature = self.getSignature(content)
url = self.getUrl(flag, signature)
result = requests.get(url).json()
return result
def listObject(self, bucket, start = 0, limit = 20):
flag, content = self.getContent(method = 'GET', bucket = bucket)
signature = self.getSignature(content)
url = self.getUrl(flag, signature, bucket = bucket, oparam = 'start=%d&limit=%d' % (start, limit))
result = requests.get(url).json()
return result
def getImg(self, bucket, obj):
flag, content = self.getContent(method = 'GET', bucket = bucket, obj = obj)
signature = self.getSignature(content)
url = self.getUrl(flag, signature, bucket, obj)
result = requests.get(url)
return result.content
class MotionDetect:
def __init__(self, device = 0, base_path = '', skey = '', upload_mode = ''):
self.mhi = None
self.lastImg = None
self.diff_threshold = 30
self.MHI_DURATION = 0.5
self.MAX_TIME_DELTA = 0.25
self.MIN_TIME_DELTA = 0.05
self.device = device
self.skey = skey
self.upload_mode = upload_mode
if base_path == '':
self.base_path = tempfile.gettempdir()
else:
self.base_path = base_path
self.pipe = multiprocessing.Pipe()
self.worker = None
def update(self, img):
h, w = img.shape[:2]
if self.mhi == None:
self.mhi = numpy.zeros((h, w), numpy.float32)
if self.lastImg == None:
self.lastImg = img
frame_diff = cv2.absdiff(img, self.lastImg)
gray_diff = cv2.cvtColor(frame_diff, cv2.COLOR_BGR2GRAY)
ret, silh = cv2.threshold(gray_diff, self.diff_threshold, 1, cv2.THRESH_BINARY)
timestamp = cv2.getTickCount() / cv2.getTickFrequency()
cv2.updateMotionHistory(silh, self.mhi, timestamp, self.MHI_DURATION)
mask, orient = cv2.calcMotionGradient(self.mhi, self.MAX_TIME_DELTA, self.MIN_TIME_DELTA, apertureSize=5)
segmask, seg_bounds = cv2.segmentMotion(self.mhi, timestamp, self.MAX_TIME_DELTA)
self.lastImg = img
count = 0
for i, rect in enumerate([(0, 0, w, h)] + list(seg_bounds)):
x, y, rw, rh = rect
area = rw*rh
if area < 64**2:
continue
count += 1
return count
def encrypt(self, img, timestamp):
ctr = Counter.new(128)
aes = AES.new(self.skey, AES.MODE_CTR, counter = ctr)
ret, text = cv2.imencode('.jpg', img, [int(cv2.IMWRITE_JPEG_QUALITY), 80])
cbin = aes.encrypt(text)
filename = os.path.join(self.base_path, timestamp + '.jpg')
outfile = open(filename, 'wb')
outfile.write(cbin)
outfile.close()
return filename
def encrypt2(self, img):
ret, text = cv2.imencode('.jpg', img, [int(cv2.IMWRITE_JPEG_QUALITY), 80])
if self.skey != '':
ctr = Counter.new(128)
aes = AES.new(self.skey, AES.MODE_CTR, counter = ctr)
text = aes.encrypt(text)
return text
def decrypt(self, filename):
cbin = open(filename, 'rb').read()
ctr = Counter.new(128)
aes = AES.new(self.skey, AES.MODE_CTR, counter = ctr)
text = aes.decrypt(cbin)
open(filename + '.jpg', 'wb').write(text)
return filename + '.jpg'
def detect(self):
cap = cv2.VideoCapture(self.device)
time.sleep(2)
while True:
s = time.clock()
timestamp = datetime.datetime.now().strftime('%Y%m%d%H%M%S%f')[:-3]
ret, img = cap.read()
count = self.update(img)
if count > 3:
cbin = self.encrypt2(img)
filename = os.path.join(self.base_path, timestamp + '.jpg')
print filename
outfile = open(filename, 'wb')
outfile.write(cbin)
outfile.close()
self.processImage(timestamp)
print time.clock() - s
time.sleep(0.2)
if self.worker.is_alive():
self.worker.join()
def processImage(self, timestamp):
if self.worker == None or self.worker.is_alive() == False:
print 'start new process'
self.worker = multiprocessing.Process(target = self.processWorker, args = (self.pipe[0],))
self.worker.start()
print 'send...', timestamp
self.pipe[1].send(timestamp)
def processWorker(self, pipe):
while pipe.poll(10):
timestamp = pipe.recv()
print 'processing... %s' % timestamp
if self.upload_mode != '':
if self.upload_mode.startswith('bcs:'):
_, ak, sk = self.upload_mode.split(':')
bcs = Bcs(ak, sk)
try:
filename = os.path.join(self.base_path, timestamp + '.jpg')
bcs.upload(, 'homepics')
os.remove(filename)
print 'uploaded ' + timestamp
except:
print 'upload failed: ' + timestamp
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument('-d', action = 'store', dest = 'device_index', default = 0, type = int, help = 'video device index, default is 0.')
parser.add_argument('-D', action = 'store', dest = 'decrypt', default = '', help = 'decrypt file.')
parser.add_argument('-i', action = 'store', dest = 'image_path', default = '', help = 'image storage directory.')
parser.add_argument('-p', action = 'store', dest = 'pwd', default = '', help = 'the password for encrypt the image file. the file will not be encrypted if pwd is null.')
parser.add_argument('-u', action = 'store', dest = 'upload_mode', default = '', help = '''store the image to Internet storage service.
Baidu Cloud Storage. parame --> bcs:app_key(ak):screct_key(sk)
Baidu PCS. [unsupported]
Sina vdisk. [unsupported]
Huawei dbank. [unsupported]
''')
args = parser.parse_args()
motion = MotionDetect(args.device_index, args.image_path, args.pwd, args.upload_mode)
if args.decrypt != '':
if args.pwd != '':
motion.decrypt(args.decrypt)
else:
print 'decrypt need a password(-p pwd)'
else:
motion.detect()