title: What is the difference between warpPerspective and perspectiveTransform?
body: <p>I have used four sets of points to get a perspective transform matrix. Then using <code>warpPerspective</code> to transform the matrix <code>A</code> to matrix <code>B</code>. Point a from Mat A. I want to get the new point a position in mat B. But <code>warpPerspective</code> cannot do that, while <code>perspectiveTransform</code> can. </p>
  
  <p>Here I want to know if the position that <code>perspectiveTransform</code> gets is the same as the position in matrix B by using <code>warpPerspective</code>.</p>
  
  <p>So, what is the difference between <code>warpPerspective</code> and <code>perspectiveTransform</code>?</p>
  
  <pre><code>Mat trans = getPerspectiveTransform(dst, gpsPoints);
  warpPerspective(A, B, trans, image.size());
  Point2f a = Point2f(..., ...);         //were known
  vector&lt;Point2f&gt; obj(1);
  obj[0] = a;
  vector&lt;Point2f&gt; b; 
  perspectiveTransform(obj, b, trans);//if the new point in B is c, is c equals to b?
  </code></pre>