python 2.7 - limited framerate picamera v2 -

question framerates on picamera v2: according documentation of picamera , following framerates feasible hardware:

resolution  aspect ratio    framerates  video   image   fov     binning 1   1920x1080   16:9    0.1-30fps   x       partial     none 2   3280x2464   4:3     0.1-15fps   x   x   full    none 3   3280x2464   4:3     0.1-15fps   x   x   full    none 4   1640x1232   4:3     0.1-40fps   x       full    2x2 5   1640x922    16:9    0.1-40fps   x       full    2x2 6   1280x720    16:9    40-90fps    x       partial     2x2 7   640x480     4:3     40-90fps    x       partial     2x2 

however, when gathering images capture_sequence method (which in documentation referred fastest method) don't close these numbers.

for 1280x720 rate maxes out @ 25 fps, @ 640x480 maxes out close 60.

the calculations i'm performing irrelevant i.e. commenting them out doesn't make difference (calculations fast enough not cause of issue). if see flaws in i'm try , solve increasing framerate ... .

import io import time import picamera #import multiprocessing multiprocessing.pool import threadpool #import threading import cv2 #from pil import image referenceimage import referenceimage detectobject_stream import detectobject_stream collections import deque datawriter import datawriter   backgroundimage=referenceimage() threadn = cv2.getnumberofcpus() pool = threadpool(processes = threadn) pending = deque() numberofimages=500  starttime=time.time()  #datawrite=datawriter() #datawrite.start()  def outputs():     stream = io.bytesio()     start=true     global backgroundimage     in range(numberofimages):         yield stream          #print time.time()-starttime         #start = time.time()         while len(pending) > 0 , pending[0].ready():             timestamps = pending.popleft().get()             #print timestamps             if len(pending)<threadn:             stream.seek(0)             task = pool.apply_async(detectobject_stream, (stream.getvalue(),backgroundimage,start,0))         pending.append(task)             start=false          stoptime = time.time()          print stoptime-start          stream.seek(0)         stream.truncate()         #print  picamera.picamera() camera:     #camera.resolution = (640, 480)     camera.resolution = (1280, 720)     camera.framerate = 60     camera.start_preview()      time.sleep(2)     start = time.time()     camera.capture_sequence(outputs(),format='bgr',use_video_port=true)     finish = time.time()     print('captured images @ %.2ffps' % (numberofimages / (finish - start))) 

thanks in advance