print('type(img1):',type(img1)) #type(img1):<class'numpy.ndarray'>
print('img1.shape:',img1.shape) #img1.shape:(480,640)
print('img2.shape:',img2.shape) #img2.shape:(480,640,3)
print('img2.dtype:',img2.dtype) #img2.dtype:uint8
Reference
1) 제로베이스 데이터스쿨 강의자료