CS1674: Homework 4 - Written

1. [3 pts] What does it mean to quantize the gradient orientations?
2. [3 pts] What is the effect of gradient magnitude on the histogram of gradient orientations, in the computation of the SIFT descriptor?
3. [3 pts] How can we find to which cluster we should assign a new feature, which was not part of the set of features used to compute the clustering?
4. [3 pts] How do we use clustering to compute a bag-of-words image representation?
5. [3 pts] When is it more efficient to create an inverted file index to match a query image to other images in the database, rather than comparing the query to all database images without an index?