python中数字图像处理出现报错(-5:Bad argument)

OpenCV(4.5.2) :-1: error: (-5:Bad argument) in function 'drawKeypoints'
> Overload resolution failed:
>  - drawKeypoints() missing required argument 'outImage' (pos 3)
>  - drawKeypoints() missing required argument 'outImage' (pos 3)

以上是报错全部，

gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
img = cv2.drawKeypoints(imagre1,imagre,color=(255,0,255))
dest = cv2.drawMatchesKnn(imagre1,imagre,None,flags=2)

这是我使用的代码

求大神解决

drawKeypoints少了个参数，应该是drawKeypoints(imagre1,imagre,outImage，color=(255,0,255))，少个outImage

name 'outImage' is not defined