cv2.error: OpenCV(4.5.5)

[Strive1s]

import dxcam import cv2

camera = dxcam.create() camera.grab() region=[0,0,480,480] while True: img = camera.grab(region=region) img = cv2.cvtColor(img,cv2.COLOR_RGB2BGR) cv2.imshow("window",img) if cv2.waitKey(1) & 0xFF ==ord('d'): cv2.destroyAllWindows() break I always get an error when I test, the program can only run for a short time before the error occurs

Erro Code: Traceback (most recent call last): File "c:/Users/Administrator/Desktop/DXcam-main/dxcamtest.py", line 9, in img = cv2.cvtColor(img,cv2.COLOR_RGB2BGR) cv2.error: OpenCV(4.5.5) D:\a\opencv-python\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

[ra1nty]

It is worth noting that .grab will return None if there is no new frame since the last time you called .grab. Usually it means there's nothing new to render since last time (E.g. You are idling).

You should add an additional condition to check if the returned value is None. Also, if you want BGR output you can simply use:

camera = dxcam.create(output_color=“BGR”)

[Strive1s]

import dxcam import cv2

left, top = (2560 - 640) // 2, (1440 - 640) // 2 right, bottom = left + 640, top + 640 region = (left, top, right, bottom) camera = dxcam.create(output_color="BGR") while True: img = camera.grab(region=region) if camera.grab(region=region) is not None: cv2.imshow('window',img) if cv2.waitKey(1) & 0xFF ==ord('d'): cv2.destroyAllWindows() break

I changed my code and it still seems to be a problem, it still doesn't work.

[ra1nty]

import dxcam
import cv2
left, top = (2560 - 640) // 2, (1440 - 640) // 2
right, bottom = left + 640, top + 640
region = (left, top, right, bottom)
camera = dxcam.create(output_color="BGR")
while True:
    img = camera.grab(region=region)
    if img is not None:
        cv2.imshow('window',img)
    if cv2.waitKey(1) & 0xFF ==ord('d'):
        cv2.destroyAllWindows()
        break

Check the returned variable from .grab