title: SIFT and SURF feature extraction Implementation using MATLAB
body: <p>I am doing an ancient coins recognition system using matlab. What I have done so far is:</p>
  
  <ol>
  <li>convert to grayscale</li>
  <li>remove noise using Gaussian filter</li>
  <li>contrast enhancement</li>
  <li>edge detection using canny edge detector.</li>
  </ol>
  
  <p>Now I want to extract feature for classification. Features I thought to select are roundness, area, colour, SIFT and SURF. My problem is how I can apply SIFT and SURF algorithms to my project. I couldn't find built-in functions for both. </p>