How to make Frame Rate constant of Allied Vision Camera using Vimba SDK?

Question

I am using Allied Vision Camera Manta G-201C for a project. The requirement is of constant 30 FPS (Fames Per Second), but I am having a higher rate of 33-34 and is not constant.

The following code I am using:

#! /usr/bin/python3.7

from datetime import datetime
from functools import partial
import queue
import time

from vimba import *
import cv2


def setup_camera(cam):
    cam.set_pixel_format(PixelFormat.BayerRG8)
    cam.ExposureTimeAbs.set(10000)
    cam.BalanceWhiteAuto.set('Off')
    cam.Gain.set(0)
    cam.AcquisitionMode.set('Continuous')
    cam.GainAuto.set('Off')
    # NB: Following adjusted for my Manta G-033C
    cam.Height.set(492)
    cam.Width.set(656)

# Called periodically as frames are received by Vimba's capture thread
# NB: This is invoked in a different thread than the rest of the code!
def frame_handler(frame_queue, cam, frame):
    img = frame.as_numpy_ndarray()
    img_rgb = cv2.cvtColor(img, cv2.COLOR_BAYER_RG2RGB)
    try:
        # Try to put the frame in the queue...
        frame_queue.put_nowait(img_rgb)
    except queue.Full:
        # If that fials (queue is full), just drop the frame
        # NB: You may want to handle this better...
        print('Dropped Frame')
    cam.queue_frame(frame)
    
def do_something(img, count):
    filename = 'data/IMG_' + str(count) + '.jpg'
    cv2.putText(img, str(datetime.now()), (20, 40)
        , cv2.FONT_HERSHEY_PLAIN, 2, (255, 255, 255)
        , 2, cv2.LINE_AA)
    cv2.imwrite(filename, img)

def run_processing(cam):
    try:
        # Create a queue to use for communication between Vimba's capture thread
        # and the main thread, limit capacity to 10 entries
        frame_queue = queue.Queue(maxsize=10)
        # Start asynchronous capture, using frame_handler
        # Bind the first parameter of frame handler to our frame_queue
        cam.start_streaming(handler=partial(frame_handler,frame_queue)
            , buffer_count=10)

        start = time.time()
        frame_count = 0
        while True:
            if frame_queue.qsize() > 0:
                # If there's something in the queue, try to fetch it and process
                try:
                    frame = frame_queue.get_nowait()
                    frame_count += 1
                    cv2.imshow('Live feed', frame)
                    do_something(frame, frame_count)
                except queue.Empty:
                    pass
                
            key = cv2.waitKey(1)
            if (key == ord('q')) or (frame_count >= 100):
                cv2.destroyAllWindows()
                break
        
        fps = int((frame_count + 1)/(time.time() - start))
        print('FPS:', fps)
    finally:
        # Stop the asynchronous capture
        cam.stop_streaming()

#@profile
def main():
    with Vimba.get_instance() as vimba:
        with vimba.get_all_cameras()[0] as cam:
            setup_camera(cam)
            run_processing(cam)

if __name__ == "__main__":
    main()

I want to have a constant FPS of 30 for image capturing. I don't know how to solve this? Any idea is appreciated!

Answer 1

You can set a static framerate with this feature:

AcquisitionFrameRateAbs

If TriggerSelector = FrameStart and either TriggerMode = Off or TriggerSource = FixedRate, this feature specifies the frame rate. Depending on the exposure duration, the camera may not achieve the frame rate set here.

More information about the features would be in the Feature Reference on the Manta Documentation Download site.

With Vimba Python you use:

feature = cam.get_feature_by_name("AcquisitionFrameRateAbs")
feature.set(30) #specifies 30FPS
# set the other features TriggerSelector and TriggerMode
feature = cam.get_feature_by_name("TriggerSelector")
feature.set("FrameStart")
feature = cam.get_feature_by_name("TriggerMode")
feature.set("Off")