PI camera 加速方法 (!?

昨天看到一篇文章在介紹提升 PI 的FPS
https://www.pyimagesearch.com/2015/12/28/increasing-raspberry-pi-fps-with-python-and-opencv/

然後用他的sample code測了一下, 結果是:

pi@raspberrypi:~$ python3 picamera_fps_demo.py
[INFO] sampling frames from `picamera` module...
[INFO] elasped time: 3.21
[INFO] approx. FPS: 31.47 (by cv2.VideoCapture(0))

[INFO] sampling THREADED frames from `picamera` module...
[INFO] elasped time: 0.32
[INFO] approx. FPS: 309.94 (by PiVideoStream().start())

pi@raspberrypi:~$ python3 fps_demo.py
[INFO] sampling frames from webcam...
[INFO] elasped time: 3.77
[INFO] approx. FPS: 26.51 (by cv2.VideoCapture(0))

[INFO] sampling THREADED frames from webcam...
[INFO] elasped time: 1.74
[INFO] approx. FPS: 57.59 (by WebcamVideoStream(src=0).start())

看了一下code, 主要差異是讀取video的語法

[方法1: 大約30FPS]

import cv2

stream = cv2.VideoCapture(0)

[方法2: 大約58FPS]

from imutils.video import WebcamVideoStream

vs = WebcamVideoStream(src=0).start()

[方法3: 大約300FPS] 驚!!!!!!!!!!!!!!

from imutils.video.pivideostream import PiVideoStream

vs = PiVideoStream().start()