face: add a toplevel node to write(String) method

modules/face/src/face_basic.cpp

@@ -53,7 +53,10 @@ cv::Mat BasicFaceRecognizer::getMean() const
 void BasicFaceRecognizer::read(const FileNode& fs)
 {
     //read matrices
-    fs["threshold"] >> _threshold;
+    double _t = 0;
+    fs["threshold"] >> _t; // older versions might not have "threshold"
+    if (_t !=0)
+        _threshold = _t;    // be careful, not to overwrite DBL_MAX with 0 !
     fs["num_components"] >> _num_components;
     fs["mean"] >> _mean;
     fs["eigenvalues"] >> _eigenvalues;

modules/face/src/facerec.cpp

@@ -59,7 +59,7 @@ void FaceRecognizer::read(const String &filename)
     FileStorage fs(filename, FileStorage::READ);
     if (!fs.isOpened())
         CV_Error(Error::StsError, "File can't be opened for reading!");
-    this->read(fs.root());
+    this->read(fs.getFirstTopLevelNode());
     fs.release();
 }
 
@@ -68,7 +68,9 @@ void FaceRecognizer::write(const String &filename) const
     FileStorage fs(filename, FileStorage::WRITE);
     if (!fs.isOpened())
         CV_Error(Error::StsError, "File can't be opened for writing!");
+    fs << getDefaultName() << "{";
     this->write(fs);
+    fs << "}";
     fs.release();
 }
 

modules/face/src/lbph_faces.cpp

@@ -115,7 +115,10 @@ public:
 
 
 void LBPH::read(const FileNode& fs) {
-    fs["threshold"] >> _threshold;
+    double _t = 0;
+    fs["threshold"] >> _t; // older versions might not have "threshold"
+    if (_t !=0)
+        _threshold = _t;    // be careful, not to overwrite DBL_MAX with 0 !
     fs["radius"] >> _radius;
     fs["neighbors"] >> _neighbors;
     fs["grid_x"] >> _grid_x;

modules/face/test/test_loadsave.cpp

+/*
+By downloading, copying, installing or using the software you agree to this
+license. If you do not agree to this license, do not download, install,
+copy or use the software.
+
+                          License Agreement
+               For Open Source Computer Vision Library
+                       (3-clause BSD License)
+
+Copyright (C) 2013, OpenCV Foundation, all rights reserved.
+Third party copyrights are property of their respective owners.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+  * Redistributions of source code must retain the above copyright notice,
+    this list of conditions and the following disclaimer.
+
+  * Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+  * Neither the names of the copyright holders nor the names of the contributors
+    may be used to endorse or promote products derived from this software
+    without specific prior written permission.
+
+This software is provided by the copyright holders and contributors "as is" and
+any express or implied warranties, including, but not limited to, the implied
+warranties of merchantability and fitness for a particular purpose are
+disclaimed. In no event shall copyright holders or contributors be liable for
+any direct, indirect, incidental, special, exemplary, or consequential damages
+(including, but not limited to, procurement of substitute goods or services;
+loss of use, data, or profits; or business interruption) however caused
+and on any theory of liability, whether in contract, strict liability,
+or tort (including negligence or otherwise) arising in any way out of
+the use of this software, even if advised of the possibility of such damage.
+*/
+
+#include "test_precomp.hpp"
+
+// regression for #1267
+// let's make sure, that both Algorithm::save(String) and
+// FaceRecognizer::write(String) lead to the same result
+
+void make_test_data(std::vector<cv::Mat> &images, std::vector<int> &labels) {
+    for (int i=0; i<5; i++) {
+        cv::Mat m(100,100,CV_8U);
+        cv::randu(m,0,255);
+        images.push_back(m);
+        labels.push_back(i);
+    }
+}
+
+TEST(CV_Face_SAVELOAD, use_save) {
+    std::vector<cv::Mat> images;
+    std::vector<int> labels;
+    make_test_data(images, labels);
+    cv::Ptr<cv::face::FaceRecognizer> model1 = cv::face::LBPHFaceRecognizer::create();
+    model1->train(images,labels);
+    model1->save("fr.xml");
+    int p1 = model1->predict(images[2]);
+    cv::Ptr<cv::face::FaceRecognizer> model2 = cv::face::LBPHFaceRecognizer::create();
+    model2->read("fr.xml");
+    EXPECT_EQ(model2->empty(), false);
+    EXPECT_EQ(p1, model2->predict(images[2]));
+}
+
+TEST(CV_Face_SAVELOAD, use_write) {
+    std::vector<cv::Mat> images;
+    std::vector<int> labels;
+    make_test_data(images, labels);
+    cv::Ptr<cv::face::FaceRecognizer> model1 = cv::face::LBPHFaceRecognizer::create();
+    model1->train(images,labels);
+    model1->write("fr.xml");
+    int p1 = model1->predict(images[2]);
+    cv::Ptr<cv::face::FaceRecognizer> model2 = cv::face::LBPHFaceRecognizer::create();
+    model2->read("fr.xml");
+    EXPECT_EQ(model2->empty(), false);
+    EXPECT_EQ(p1, model2->predict(images[2]));
+}