Get frames from Picamera and add opencv filters in realtime

Question

According to this Picamera document, Picamera can capturing frame as openCV object. but seems not working . how can i get frames from Picamera and add opencv filters in realtime. Rpi 3b+ . Python 2.7 i need an example code please.

import time
import picamera
import numpy as np
import cv2

with picamera.PiCamera() as camera:
    camera.resolution = (320, 240)
    camera.framerate = 24
    time.sleep(2)
    image = np.empty((240 * 320 * 3,), dtype=np.uint8)
    camera.capture(image, 'bgr')
    image = image.reshape((240, 320, 3))

Answer 1

Edit: 23rd April, 2022. Ok. I'm going back to your previously original coded. I'm using picamera v1. kindly, try to understanding. while cap.isOpened() is equivalent to camera.start_preview() You need time interval how long do you want to stay. So I set time.sleep(30) for 30 seconds. Do not used image.reshape. You already have camera.resolution = (320, 240). So here is previously coded. So I commented it out. try this:

import time
import picamera
import numpy as np
import cv2

with picamera.PiCamera() as camera:
    camera.resolution = (320, 240)
    camera.start_preview()
    camera.framerate = 24
    time.sleep(30)
    #image = np.empty((240 * 320 * 3,), dtype=np.uint8)
    camera.capture(image, 'bgr')
    #image = image.reshape((240, 320, 3))

Here another one how to save multiple images.

import time
import picamera

with picamera.PiCamera() as camera:
    camera.resolution = (640, 480)
    camera.start_preview()
    time.sleep(2)
    for filename in camera.capture_continuous('img{counter:03d}.jpg'):
        print('Captured %s' % filename)
        time.sleep(10) # wait 10 seconds