python OpenCV（3.4.2）错误：（-215：断言失败）

Question

I'm trying to use the SIFT descriptors for image matching. I am planning to match one image with another.

This is the code with which I am trying to make the match

sift = cv2.xfeatures2d.SIFT_create()

kp_1, desc_1 = sift.detectAndCompute(original, None)
kp_2, desc_2 = sift.detectAndCompute(image_to_compare, None)
index_params = dict(algorithm=0, trees=5)
search_params = dict()
flann = cv2.FlannBasedMatcher(index_params, search_params)
matches = flann.knnMatch(desc_1, desc_2, k=2)

but I get the following error:

<ipython-input-6-1f81512d446c> in AlgSift(imagen, imagentocompare, umbral)
   21     search_params = dict()
   22     flann = cv2.FlannBasedMatcher(index_params, search_params)
---> 23     matches = flann.knnMatch(desc_1, desc_2, k=2)
   24 
   25 


   error: OpenCV(3.4.2) /io/opencv/modules/flann/src/miniflann.cpp:487: error: 
   (-215:Assertion failed) (size_t)knn <= index_->size() in function 
   'runKnnSearch_'

Answer 1

An error such as Assertion failed occurred in my case because the position of the image to be loaded was not correct. Please check your storage location and code once.