Error with sift.detectAndCompute() in OpenCV 4.5.1

[kgdthomas]

Can this be run on OpenCV 4.5.1? I'm having an error pointing back at
#detect sift features for both images
sift = cv2.SIFT_create()

kp1, des1 = sift.detectAndCompute(img1 , None)
kp2, des2 = sift.detectAndCompute(img2 , None)

This area of the code.

The error is as follows:

Traceback (most recent call last):
File "C:\Users\Kent-ROG\PycharmProjects\pythonProject\venv\lib\site-packages\IPython\core\interactiveshell.py", line 3418, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "", line 33, in
kp1, des1 = sift.detectAndCompute(img1 , None)
cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-i1s8y2i1\opencv\modules\features2d\src\sift.dispatch.cpp:477: error: (-5:Bad argument) image is empty or has incorrect depth (!=CV_8U) in function 'cv::SIFT_Impl::detectAndCompute'

I hope you can assist me.