added CameraInfo class into opencv_stitching

modules/stitching/camera.cpp

@@ -0,0 +1,31 @@
+#include <fstream>
+#include "camera.hpp"
+
+using namespace std;
+using namespace cv;
+
+
+CameraInfo CameraInfo::load(const string &path)
+{
+    FileStorage fs(path, FileStorage::READ);
+    CV_Assert(fs.isOpened());
+
+    CameraInfo cam;
+    if (!fs["R"].isNone())
+        fs["R"] >> cam.R;
+    if (!fs["K"].isNone())
+        fs["K"] >> cam.K;
+    return cam;
+}
+
+
+void CameraInfo::save(const string &path)
+{
+    FileStorage fs(path, FileStorage::WRITE);
+    CV_Assert(fs.isOpened());
+
+    if (!R.empty())
+        fs << "R" << R;
+    if (!K.empty())
+        fs << "K" << K;
+}