added image stitching module

modules/stitching/util.hpp

@@ -0,0 +1,72 @@
+#ifndef _OPENCV_STITCHING_UTIL_HPP_
+#define _OPENCV_STITCHING_UTIL_HPP_
+
+#include <vector>
+#include <list>
+#include <opencv2/core/core.hpp>
+
+#define ENABLE_LOG 1
+
+#if ENABLE_LOG
+  #include <iostream>
+  #define LOG(msg) std::cout << msg;
+#else
+  #define LOG(msg)
+#endif
+
+#define LOGLN(msg) LOG(msg << std::endl)
+
+
+class DjSets
+{
+public:
+    DjSets(int n = 0) { create(n); }
+
+    void create(int n);
+    int find(int elem);
+    int merge(int set1, int set2);
+
+    std::vector<int> parent;
+    std::vector<int> size;
+
+private:
+    std::vector<int> rank_;
+};
+
+
+struct GraphEdge
+{
+    GraphEdge(int from, int to, float weight) 
+        : from(from), to(to), weight(weight) {}
+    bool operator <(const GraphEdge& other) const { return weight < other.weight; }
+    bool operator >(const GraphEdge& other) const { return weight > other.weight; }
+
+    int from, to;
+    float weight;
+};
+
+
+class Graph
+{
+public:
+    Graph(int num_vertices = 0) { create(num_vertices); }
+
+    void create(int num_vertices) { edges_.assign(num_vertices, std::list<GraphEdge>()); }
+
+    int numVertices() const { return static_cast<int>(edges_.size()); }
+
+    void addEdge(int from, int to, float weight);
+
+    template <typename B>
+    B forEach(B body) const;
+
+    template <typename B> 
+    B walkBreadthFirst(int from, B body) const;
+    
+private:
+    std::vector< std::list<GraphEdge> > edges_;
+};
+
+#include "util_inl.hpp"
+
+#endif // _OPENCV_STITCHING_UTIL_HPP_