dlib C++ Library - scan_image_pyramid_tools.h

// Copyright (C) 2011 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_SCAN_IMaGE_PYRAMID_TOOLS_Hh_
#define DLIB_SCAN_IMaGE_PYRAMID_TOOLS_Hh_
#include "scan_image_pyramid_tools_abstract.h"
#include "../statistics.h"
#include <list>
#include "../geometry.h"
#include <iostream>
namespace dlib
{
// ----------------------------------------------------------------------------------------
 namespace impl
 {
 inline bool compare_first (
 const std::pair<unsigned long,rectangle>& a,
 const std::pair<unsigned long,rectangle>& b
 )
 {
 return a.first < b.first;
 }
 }
 template <typename image_scanner_type>
 std::vector<rectangle> determine_object_boxes (
 const image_scanner_type& scanner,
 const std::vector<rectangle>& rects,
 double min_match_score
 )
 {
 // make sure requires clause is not broken
 DLIB_ASSERT(0 < min_match_score && min_match_score <= 1,
 "\t std::vector<rectangle> determine_object_boxes()"
 << "\n\t Invalid inputs were given to this function. "
 << "\n\t min_match_score: " << min_match_score 
 );
 typename image_scanner_type::pyramid_type pyr;
 typedef std::list<std::pair<unsigned long, rectangle> > list_type;
 unsigned long max_area = 0;
 // Copy rects into sorted_rects and sort them in order of increasing area. But
 // only include the rectangles that aren't already obtainable by the scanner.
 list_type sorted_rects;
 for (unsigned long i = 0; i < rects.size(); ++i)
 {
 if (scanner.get_num_detection_templates() > 0)
 {
 rectangle temp = scanner.get_best_matching_rect(rects[i]);
 const double match_score = (rects[i].intersect(temp).area())/(double)(rects[i] + temp).area();
 // skip this rectangle if it's already matched well enough.
 if (match_score > min_match_score)
 continue;
 }
 max_area = std::max(rects[i].area(), max_area);
 sorted_rects.push_back(std::make_pair(rects[i].area(), rects[i]));
 }
 sorted_rects.sort(dlib::impl::compare_first);
 // Make sure this area value is comfortably larger than all the 
 // rectangles' areas.
 max_area = 3*max_area + 100;
 std::vector<rectangle> object_boxes;
 while (sorted_rects.size() != 0)
 {
 rectangle cur = sorted_rects.front().second;
 sorted_rects.pop_front();
 object_boxes.push_back(centered_rect(point(0,0), cur.width(), cur.height()));
 // Scale cur up the image pyramid and remove any rectangles which match.
 // But also stop when cur gets large enough to not match anything.
 for (unsigned long itr = 0; 
 itr < scanner.get_max_pyramid_levels() && cur.area() < max_area; 
 ++itr)
 {
 list_type::iterator i = sorted_rects.begin();
 while (i != sorted_rects.end())
 {
 const rectangle temp = move_rect(i->second, cur.tl_corner());
 const double match_score = (cur.intersect(temp).area())/(double)(cur + temp).area();
 if (match_score > min_match_score)
 {
 i = sorted_rects.erase(i);
 }
 else
 {
 ++i;
 }
 }
 cur = pyr.rect_up(cur);
 }
 }
 return object_boxes;
 }
// ----------------------------------------------------------------------------------------
 template <typename image_scanner_type>
 std::vector<rectangle> determine_object_boxes (
 const image_scanner_type& scanner,
 const std::vector<std::vector<rectangle> >& rects,
 double min_match_score
 )
 {
 // make sure requires clause is not broken
 DLIB_ASSERT(0 < min_match_score && min_match_score <= 1,
 "\t std::vector<rectangle> determine_object_boxes()"
 << "\n\t Invalid inputs were given to this function. "
 << "\n\t min_match_score: " << min_match_score 
 );
 std::vector<rectangle> temp;
 for (unsigned long i = 0; i < rects.size(); ++i)
 {
 for (unsigned long j = 0; j < rects[i].size(); ++j)
 {
 temp.push_back(rects[i][j]);
 }
 }
 return determine_object_boxes(scanner, temp, min_match_score);
 }
// ----------------------------------------------------------------------------------------
 template <typename image_scanner_type>
 void setup_grid_detection_templates (
 image_scanner_type& scanner,
 const std::vector<std::vector<rectangle> >& rects,
 unsigned int cells_x,
 unsigned int cells_y,
 double min_match_score = 0.75
 )
 {
 const std::vector<rectangle>& object_boxes = determine_object_boxes(scanner, rects, min_match_score);
 for (unsigned long i = 0; i < object_boxes.size(); ++i)
 {
 scanner.add_detection_template(object_boxes[i], create_grid_detection_template(object_boxes[i], cells_x, cells_y));
 }
 }
// ----------------------------------------------------------------------------------------
 template <typename image_scanner_type>
 void setup_grid_detection_templates_verbose (
 image_scanner_type& scanner,
 const std::vector<std::vector<rectangle> >& rects,
 unsigned int cells_x,
 unsigned int cells_y,
 double min_match_score = 0.75
 )
 {
 const std::vector<rectangle>& object_boxes = determine_object_boxes(scanner, rects, min_match_score);
 std::cout << "number of detection templates: "<< object_boxes.size() << std::endl;
 for (unsigned long i = 0; i < object_boxes.size(); ++i)
 {
 std::cout << " object box " << i << ": width: " << object_boxes[i].width() 
 << " height: "<< object_boxes[i].height() << std::endl;
 scanner.add_detection_template(object_boxes[i], create_grid_detection_template(object_boxes[i], cells_x, cells_y));
 }
 }
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_SCAN_IMaGE_PYRAMID_TOOLS_Hh_