Graph.cpp

/**
 * @author Manuel Guenther <manuel.guenther@idiap.ch>
 * @date Wed Jun 11 17:20:43 CEST 2014
 *
 * @brief The C++ implementations of a Graph of Gabor jets
 *
 * Copyright (C) 2011-2014 Idiap Research Institute, Martigny, Switzerland
 */

#include <bob.ip.gabor/Graph.h>

/**
 * Generates grid graphs which will be placed according to the given eye positions
 * @param lefteye  Position of the left eye
 * @param righteye Position of the right eye
 * @param between  Number of nodes to place between the eyes (excluding the eye nodes themselves)
 * @param along    Number of nodes to place left and right of the eye nodes (excluding the eye nodes themselves)
 * @param above    Number of nodes to place above the eyes (excluding the eye nodes themselves)
 * @param below    Number of nodes to place below the eyes (excluding the eye nodes themselves)
 */
bob::ip::gabor::Graph::Graph(
  blitz::TinyVector<int,2> righteye,
  blitz::TinyVector<int,2> lefteye,
  int between,
  int along,
  int above,
  int below
)
{
  // shortcuts for eye positions
  int rex = righteye[1], rey = righteye[0];
  int lex = lefteye[1], ley = lefteye[0];
  // compute grid parameters
  double stepx = double(lex - rex) / double(between+1);
  double stepy = double(ley - rey) / double(between+1);
  double xstart = rex - along*stepx + above*stepy;
  double ystart = rey - along*stepy - above*stepx;
  int xcount = between + 2 * (along+1);
  int ycount = above + below + 1;

  // create grid positions
  m_nodes.resize(xcount*ycount);
  for (int y = 0, i = 0; y < ycount; ++y){
    for (int x = 0; x < xcount; ++x, ++i){
      // y position
      m_nodes[i][0] = round(ystart + y * stepx + x * stepy);
      // x position
      m_nodes[i][1] = round(xstart + x * stepx - y * stepy);
    }
  }
}

/**
 * Generates a grid graph starting at the given first index, ending at (or before) the given last index, and advancing the given step size.
 * @param first  First node to be placed (top-left)
 * @param last   Last node to be placed (bottom-right). Depending on the step size, this node might not be reached.
 * @param step   The step size (in pixel) between two nodes
 */
bob::ip::gabor::Graph::Graph(
  blitz::TinyVector<int,2> first,
  blitz::TinyVector<int,2> last,
  blitz::TinyVector<int,2> step
)
{
  int ycount = (last[0] - first[0]) / step[0] + 1;
  int xcount = (last[1] - first[1]) / step[1] + 1;

  // create grid positions
  m_nodes.resize(xcount*ycount);
  for (int y = 0, i = 0; y < ycount; ++y){