I need help about SIFT descriptors. I read some papers and reports but I found them a bit complicated. Can anyone recommend simple documents, presentations, reports about SIFT?
You could try the Scholarpedia article on SIFT:
http://www.scholarpedia.org/article/Scale_Invariant_Feature_Transform
SIFT are quite standard in computer vision, though there are many types of features that are in use: histograms of gradients, wavelets, LESH, GLOH, ORB, SURF, to mention a few... You might want to check them out if working on image analysis.
As for the descriptor in SIFT, it is simply a set of binned orientation histograms computed on some pixel neighborhoods around the keypoint. The descriptor size may vary (it's not necessarily 128, you can make it smaller or wider) - and you could also use PCA/SVD for some dimensionality reduction, unless I am mistaken
Look at the SIFT section of this MATLAB Tutorial by Gonzalo Vaca-Castano: http://www.cs.ucf.edu/~gvaca/REU2012/
The tutorial references this blog series: http://www.aishack.in/2010/05/sift-scale-invariant-feature-transform/
Salam Hadjer,http://www.vlfeat.org/~vedaldi/code/sift.html
the link contains document about SIFT and a matlab C implementation
http://web.eecs.umich.edu/~silvio/teaching/EECS598/lectures/lecture10_1.pdf
There is a good blog on this, which explains these feature detection algorithm step by step , which you can easily follow.
http://www.aishack.in/2010/05/sift-scale-invariant-feature-transform/
Good luck.
- Badges
- Science topic
- Similar topics
- Engineering
- Electrical Engineering
- Signal Processing
- Image Processing