I am developing a GUI with PyQt5 and I am stuck.
Because my program is running on a RaspberryPi4 I have limited processing power. I am getting video input from my webcam and want to perform face_recognition operations on this input. Due to the limited processing power i need to ignore a lot of input frames and just use every n-th frame to perform face recognition with to speed up the process.
I tried to program a delay similar to this thread: Call function every x seconds (Python) but it didn't work. Is there a possibility to directly refer to a frame?
This is the function where I am reading from the webcam:
def run(self):
checker=0
process_this_frame = 0
# capture from web cam
cap = cv2.VideoCapture(0)
cap.set(cv2.CAP_PROP_FRAME_WIDTH,640);
cap.set(cv2.CAP_PROP_FRAME_HEIGHT,300);
while True:
ret, cv_img = cap.read()
if ret:
img = cv2.resize(cv_img, (0, 0), fx=0.25, fy=0.25)
process_this_frame = process_this_frame+2
print('process_this_frame: ' , process_this_frame)
if process_this_frame % 20 == 0:
predictions = predict(img, model_path="trained_knn_model.clf")
print('showing predicted face')
cv_img = show_prediction_labels_on_image(cv_img, predictions)
checker=1
self.change_pixmap_signal.emit(cv_img)
else:
checker=0
self.change_pixmap_signal.emit(cv_img)
Specifically I am looking for a suitable if condition to execute the predict function only on every n-th frame and when I am not doing the predict on the cv_img I want to display just the frame in my else case. I tried with multiple modulo operators but did not find a suitable solution.
How can I do that? It would be cool to refer to a number of frames instead of using a time delay so I can try to find the best solution.
