So I wanted to test performance difference between python-opencv library and newest opencv compiled, on a raspberry pi 4 board. After this change cv2.resize()
stopped working in my script and only outputs max resolution from my webcam. I also tried imutils library but without success.I tried using both:
cv2.CAP_PROP_FRAME_WIDTH
cv2.CAP_PROP_FRAME_HEIGHT
But I only get a resized window not frame
Additionally I get this error GStreamer warning:Cannot query video position: status=0, value=-1, duration=-1
What have I missed?
Update: Minimal code
import cv2
from imutils.video import FPS
cap = cv2.VideoCapture(0)
#cap.set(cv2.CAP_PROP_FRAME_WIDTH,960)
#cap.set(cv2.CAP_PROP_FRAME_HEIGHT,540)
fps = FPS().start()
font = cv2.FONT_HERSHEY_DUPLEX
while cap.isOpened():
ret, frame = cap.read()
small_frame = cv2.resize(frame, (0, 0), fx=0.75, fy=0.75)
fps.update()
fps.stop()
cv2.putText(small_frame,"FPS {:.1f}".format(fps.fps()),
(10,30),font, 1.0, (255, 255, 255), 1)
cv2.imshow("Frame",small_frame)
key = cv2.waitKey(1)
if key == ord('q'):
break
if key == ord('p'):
cv2.waitKey(-1)
cap.release()
cv2.destroyAllWindows()
you are using scale and dimentions 0 togheter try this:
import cv2
img = cv2.imread('/home/img/python.png', cv2.IMREAD_UNCHANGED)
print('Original Dimensions : ',img.shape)
scale_percent = 60 # percent of original size
width = int(img.shape[1] * scale_percent / 100)
height = int(img.shape[0] * scale_percent / 100)
dim = (width, height)
# resize image
resized = cv2.resize(img, dim, interpolation = cv2.INTER_AREA)
print('Resized Dimensions : ',resized.shape)
cv2.imshow("Resized image", resized)
cv2.waitKey(0)
cv2.destroyAllWindows()
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