Merge pull request #20367 from augustinmanecy:features2d-rw

**Merge with contrib**: https://github.com/opencv/opencv_contrib/pull/3003

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or other license that is incompatible with OpenCV
- [x] The PR is proposed to proper branch
- [ ] There is reference to original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

modules/features2d/src/mser.cpp

@@ -87,6 +87,48 @@ public:
 
     virtual ~MSER_Impl() CV_OVERRIDE {}
 
+    void read( const FileNode& fn) CV_OVERRIDE
+    {
+      // if node is empty, keep previous value
+      if (!fn["delta"].empty())
+        fn["delta"] >> params.delta;
+      if (!fn["minArea"].empty())
+        fn["minArea"] >> params.minArea;
+      if (!fn["maxArea"].empty())
+        fn["maxArea"] >> params.maxArea;
+      if (!fn["maxVariation"].empty())
+        fn["maxVariation"] >> params.maxVariation;
+      if (!fn["minDiversity"].empty())
+        fn["minDiversity"] >> params.minDiversity;
+      if (!fn["maxEvolution"].empty())
+        fn["maxEvolution"] >> params.maxEvolution;
+      if (!fn["areaThreshold"].empty())
+        fn["areaThreshold"] >> params.areaThreshold;
+      if (!fn["minMargin"].empty())
+        fn["minMargin"] >> params.minMargin;
+      if (!fn["edgeBlurSize"].empty())
+        fn["edgeBlurSize"] >> params.edgeBlurSize;
+      if (!fn["pass2Only"].empty())
+        fn["pass2Only"] >> params.pass2Only;
+    }
+    void write( FileStorage& fs) const CV_OVERRIDE
+    {
+      if(fs.isOpened())
+      {
+        fs << "name" << getDefaultName();
+        fs << "delta" << params.delta;
+        fs << "minArea" << params.minArea;
+        fs << "maxArea" << params.maxArea;
+        fs << "maxVariation" << params.maxVariation;
+        fs << "minDiversity" << params.minDiversity;
+        fs << "maxEvolution" << params.maxEvolution;
+        fs << "areaThreshold" << params.areaThreshold;
+        fs << "minMargin" << params.minMargin;
+        fs << "edgeBlurSize" << params.edgeBlurSize;
+        fs << "pass2Only" << params.pass2Only;
+      }
+    }
+
     void setDelta(int delta) CV_OVERRIDE { params.delta = delta; }
     int getDelta() const CV_OVERRIDE { return params.delta; }
 
@@ -96,6 +138,24 @@ public:
     void setMaxArea(int maxArea) CV_OVERRIDE { params.maxArea = maxArea; }
     int getMaxArea() const CV_OVERRIDE { return params.maxArea; }
 
+    void setMaxVariation(double maxVariation) CV_OVERRIDE { params.maxVariation = maxVariation; }
+    double getMaxVariation() const CV_OVERRIDE { return params.maxVariation; }
+
+    void setMinDiversity(double minDiversity) CV_OVERRIDE { params.minDiversity = minDiversity; }
+    double getMinDiversity() const CV_OVERRIDE { return params.minDiversity; }
+
+    void setMaxEvolution(int maxEvolution) CV_OVERRIDE { params.maxEvolution = maxEvolution; }
+    int getMaxEvolution() const CV_OVERRIDE { return params.maxEvolution; }
+
+    void setAreaThreshold(double areaThreshold) CV_OVERRIDE { params.areaThreshold = areaThreshold; }
+    double getAreaThreshold() const CV_OVERRIDE { return params.areaThreshold; }
+
+    void setMinMargin(double min_margin) CV_OVERRIDE { params.minMargin = min_margin; }
+    double getMinMargin() const CV_OVERRIDE { return params.minMargin; }
+
+    void setEdgeBlurSize(int edge_blur_size) CV_OVERRIDE { params.edgeBlurSize = edge_blur_size; }
+    int getEdgeBlurSize() const CV_OVERRIDE { return params.edgeBlurSize; }
+
     void setPass2Only(bool f) CV_OVERRIDE { params.pass2Only = f; }
     bool getPass2Only() const CV_OVERRIDE { return params.pass2Only; }