title: Bag of visual word model for feature clustering
body: <p>I am using bag of visual words to cluster the features of the image. So far all the work i came across used BOW for clustering features computed using SIFT, SURF, etc. Maybe I missed this out but is it possible to represent Color Histogram Feature into BOW and also Edge oriented Histogram feature in BOW. </p>
  
  <p>I am working on image classifier and I want to used SIFT with RGB color Histogram as feature descriptors in Opencv. So i was wondering is it correct to concatenate the 2 feature vectors into one and add to BOW or is it correct to add SIFT feature to BOW and concatenate the Histogram feature to BOW (I am using this model as of now but I am wondering which one is correct.)</p>