error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

[bossxdev]

Hello i have an error with your code on detect_save_images files programs is report error:

File "detect_save_images.py", line 41, in gray_img= cv2.cvtColor(color_img, cv2.COLOR_BGR2GRAY) cv2.error: OpenCV(4.5.1) /home/pi/opencv-4.5.1/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

Please help me, Thanks