title: Combining multiple image descriptors (SIFT+HOG)
body: <p>Can anyone clarify as to how mutiple image descriptors can be combined together. I mean , if I do a normal SIFT , then it gives me a 128xN matrix, where N is the number of descriptors. Now to add the HOG descriptor matrix which can be of a different dimension, what is the procedure (because simply concatenating them does not sound meaningful) ?. The final output of the combination would be used to create the bag of words model using k-means clustering.</p>