SURF feature detector detects no keypoints
Greetings
This is opencv 4.1.0 on windows 10;
using the below simple image SURF feature detector gives no keypoints. code snippet:
std::vector<cv::KeyPoint> keypoints;
cv::Ptr<cv::xfeatures2d::SURF> detector = cv::xfeatures2d::SURF::create( 1 );
detector->detect( img, keypoints);
printf("keypoints.size=%zu\n", keypoints.size());
keypoints.size() is 0, any explanation?
img:
Any hints?
I have done some test with your code and your image, and i am getting also 0, i think it's because your image is too small
Yes, thank you; Copying the small image to a 64x64, getting 8 keypoints. Now I'm trying to find the minimum image size, as I cant find any hint in the docs. Have i nice weekend.
Instead of copying I just enlarge the object by 5 and get 18 keypinints...
imho, your image is not suitable for this:
please tell us: what did you want to achieve here, in general ? what's the purpose of it ?
I'm playin with the examples, just to get familiar with. Thank you for your time.