diff --git a/modules/imgcodecs/src/grfmt_bmp.hpp b/modules/imgcodecs/src/grfmt_bmp.hpp
index b4443b7dcc..ccbaa9140d 100644
--- a/modules/imgcodecs/src/grfmt_bmp.hpp
+++ b/modules/imgcodecs/src/grfmt_bmp.hpp
@@ -58,18 +58,18 @@ enum BmpCompression
 
 
 // Windows Bitmap reader
-class BmpDecoder : public BaseImageDecoder
+class BmpDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     BmpDecoder();
-    ~BmpDecoder();
+    ~BmpDecoder() CV_OVERRIDE;
 
-    bool  readData( Mat& img );
-    bool  readHeader();
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
     void  close();
 
-    ImageDecoder newDecoder() const;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
 
@@ -83,15 +83,15 @@ protected:
 
 
 // ... writer
-class BmpEncoder : public BaseImageEncoder
+class BmpEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     BmpEncoder();
-    ~BmpEncoder();
+    ~BmpEncoder() CV_OVERRIDE;
 
-    bool  write( const Mat& img, const std::vector<int>& params );
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
 
-    ImageEncoder newEncoder() const;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 };
 
 }
diff --git a/modules/imgcodecs/src/grfmt_exr.hpp b/modules/imgcodecs/src/grfmt_exr.hpp
index 331d099f71..ec08028e22 100644
--- a/modules/imgcodecs/src/grfmt_exr.hpp
+++ b/modules/imgcodecs/src/grfmt_exr.hpp
@@ -63,19 +63,19 @@ using namespace Imath;
 
 /* libpng version only */
 
-class ExrDecoder : public BaseImageDecoder
+class ExrDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     ExrDecoder();
-    ~ExrDecoder();
+    ~ExrDecoder() CV_OVERRIDE;
 
-    int   type() const;
-    bool  readData( Mat& img );
-    bool  readHeader();
+    int   type() const CV_OVERRIDE;
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
     void  close();
 
-    ImageDecoder newDecoder() const;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
     void  UpSample( uchar *data, int xstep, int ystep, int xsample, int ysample );
@@ -103,15 +103,15 @@ private:
 };
 
 
-class ExrEncoder : public BaseImageEncoder
+class ExrEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     ExrEncoder();
-    ~ExrEncoder();
+    ~ExrEncoder() CV_OVERRIDE;
 
-    bool  isFormatSupported( int depth ) const;
-    bool  write( const Mat& img, const std::vector<int>& params );
-    ImageEncoder newEncoder() const;
+    bool  isFormatSupported( int depth ) const CV_OVERRIDE;
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 };
 
 }
diff --git a/modules/imgcodecs/src/grfmt_gdal.hpp b/modules/imgcodecs/src/grfmt_gdal.hpp
index 0273960490..47b360f855 100644
--- a/modules/imgcodecs/src/grfmt_gdal.hpp
+++ b/modules/imgcodecs/src/grfmt_gdal.hpp
@@ -103,7 +103,7 @@ void write_ctable_pixel( const double& pixelValue,
 /**
  * Loader for GDAL
 */
-class GdalDecoder : public BaseImageDecoder{
+class GdalDecoder CV_FINAL : public BaseImageDecoder{
 
     public:
 
@@ -115,17 +115,17 @@ class GdalDecoder : public BaseImageDecoder{
         /**
          * Destructor
         */
-        ~GdalDecoder();
+        ~GdalDecoder() CV_OVERRIDE;
 
         /**
          * Read image data
         */
-        bool readData( Mat& img );
+        bool readData( Mat& img ) CV_OVERRIDE;
 
         /**
          * Read the image header
         */
-        bool readHeader();
+        bool readHeader() CV_OVERRIDE;
 
         /**
          * Close the module
@@ -135,7 +135,7 @@ class GdalDecoder : public BaseImageDecoder{
         /**
          * Create a new decoder
         */
-        ImageDecoder newDecoder() const;
+        ImageDecoder newDecoder() const CV_OVERRIDE;
 
         /**
          * Test the file signature
@@ -144,7 +144,7 @@ class GdalDecoder : public BaseImageDecoder{
          * The reason is that GDAL tends to overlap with other image formats and it is probably
          * safer to use other formats first.
         */
-        virtual bool checkSignature( const String& signature ) const;
+        virtual bool checkSignature( const String& signature ) const CV_OVERRIDE;
 
     protected:
 
diff --git a/modules/imgcodecs/src/grfmt_gdcm.hpp b/modules/imgcodecs/src/grfmt_gdcm.hpp
index d8dc60f522..7cb7e13305 100644
--- a/modules/imgcodecs/src/grfmt_gdcm.hpp
+++ b/modules/imgcodecs/src/grfmt_gdcm.hpp
@@ -53,14 +53,14 @@ namespace cv
 {
 
 // DICOM image reader using GDCM
-class DICOMDecoder : public BaseImageDecoder
+class DICOMDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
     DICOMDecoder();
-    bool  readData( Mat& img );
-    bool  readHeader();
-    ImageDecoder newDecoder() const;
-    virtual bool checkSignature( const String& signature ) const;
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
+    virtual bool checkSignature( const String& signature ) const CV_OVERRIDE;
 };
 
 }
diff --git a/modules/imgcodecs/src/grfmt_hdr.hpp b/modules/imgcodecs/src/grfmt_hdr.hpp
index 3ed8015e00..04947eae58 100644
--- a/modules/imgcodecs/src/grfmt_hdr.hpp
+++ b/modules/imgcodecs/src/grfmt_hdr.hpp
@@ -55,34 +55,34 @@ enum HdrCompression
 };
 
 // Radiance rgbe (.hdr) reader
-class HdrDecoder : public BaseImageDecoder
+class HdrDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
     HdrDecoder();
-    ~HdrDecoder();
-    bool readHeader();
-    bool readData( Mat& img );
-    bool checkSignature( const String& signature ) const;
-    ImageDecoder newDecoder() const;
-    size_t signatureLength() const;
+    ~HdrDecoder() CV_OVERRIDE;
+    bool readHeader() CV_OVERRIDE;
+    bool readData( Mat& img ) CV_OVERRIDE;
+    bool checkSignature( const String& signature ) const CV_OVERRIDE;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
+    size_t signatureLength() const CV_OVERRIDE;
 protected:
     String m_signature_alt;
     FILE *file;
 };
 
 // ... writer
-class HdrEncoder : public BaseImageEncoder
+class HdrEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     HdrEncoder();
-    ~HdrEncoder();
-    bool write( const Mat& img, const std::vector<int>& params );
-    ImageEncoder newEncoder() const;
-    bool isFormatSupported( int depth ) const;
+    ~HdrEncoder() CV_OVERRIDE;
+    bool write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
+    bool isFormatSupported( int depth ) const CV_OVERRIDE;
 protected:
 
 };
 
 }
 
-#endif/*_GRFMT_HDR_H_*/
\ No newline at end of file
+#endif/*_GRFMT_HDR_H_*/
diff --git a/modules/imgcodecs/src/grfmt_jpeg.hpp b/modules/imgcodecs/src/grfmt_jpeg.hpp
index 628dd166e2..90d80b4b59 100644
--- a/modules/imgcodecs/src/grfmt_jpeg.hpp
+++ b/modules/imgcodecs/src/grfmt_jpeg.hpp
@@ -53,18 +53,18 @@
 namespace cv
 {
 
-class JpegDecoder : public BaseImageDecoder
+class JpegDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     JpegDecoder();
     virtual ~JpegDecoder();
 
-    bool  readData( Mat& img );
-    bool  readHeader();
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
     void  close();
 
-    ImageDecoder newDecoder() const;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
 
@@ -77,14 +77,14 @@ private:
 };
 
 
-class JpegEncoder : public BaseImageEncoder
+class JpegEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     JpegEncoder();
     virtual ~JpegEncoder();
 
-    bool  write( const Mat& img, const std::vector<int>& params );
-    ImageEncoder newEncoder() const;
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 };
 
 }
diff --git a/modules/imgcodecs/src/grfmt_jpeg2000.hpp b/modules/imgcodecs/src/grfmt_jpeg2000.hpp
index 0c0954f8b3..586f16f0fa 100644
--- a/modules/imgcodecs/src/grfmt_jpeg2000.hpp
+++ b/modules/imgcodecs/src/grfmt_jpeg2000.hpp
@@ -50,17 +50,17 @@
 namespace cv
 {
 
-class Jpeg2KDecoder : public BaseImageDecoder
+class Jpeg2KDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     Jpeg2KDecoder();
     virtual ~Jpeg2KDecoder();
 
-    bool  readData( Mat& img );
-    bool  readHeader();
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
     void  close();
-    ImageDecoder newDecoder() const;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
     bool  readComponent8u( uchar *data, void *buffer, int step, int cmpt,
@@ -73,15 +73,15 @@ protected:
 };
 
 
-class Jpeg2KEncoder : public BaseImageEncoder
+class Jpeg2KEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     Jpeg2KEncoder();
     virtual ~Jpeg2KEncoder();
 
-    bool  isFormatSupported( int depth ) const;
-    bool  write( const Mat& img, const std::vector<int>& params );
-    ImageEncoder newEncoder() const;
+    bool  isFormatSupported( int depth ) const CV_OVERRIDE;
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 
 protected:
     bool  writeComponent8u( void *img, const Mat& _img );
diff --git a/modules/imgcodecs/src/grfmt_pam.hpp b/modules/imgcodecs/src/grfmt_pam.hpp
index 8b3b1f10c9..3b740e3692 100644
--- a/modules/imgcodecs/src/grfmt_pam.hpp
+++ b/modules/imgcodecs/src/grfmt_pam.hpp
@@ -59,19 +59,19 @@
 namespace cv
 {
 
-class PAMDecoder : public BaseImageDecoder
+class PAMDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     PAMDecoder();
-    virtual ~PAMDecoder();
+    virtual ~PAMDecoder() CV_OVERRIDE;
 
-    bool  readData( Mat& img );
-    bool  readHeader();
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
 
-    size_t signatureLength() const;
-    bool checkSignature( const String& signature ) const;
-    ImageDecoder newDecoder() const;
+    size_t signatureLength() const CV_OVERRIDE;
+    bool checkSignature( const String& signature ) const CV_OVERRIDE;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
 
@@ -82,18 +82,18 @@ protected:
 };
 
 
-class PAMEncoder : public BaseImageEncoder
+class PAMEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     PAMEncoder();
-    virtual ~PAMEncoder();
+    virtual ~PAMEncoder() CV_OVERRIDE;
 
-    bool  isFormatSupported( int depth ) const;
-    bool  write( const Mat& img, const std::vector<int>& params );
+    bool  isFormatSupported( int depth ) const CV_OVERRIDE;
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
 
-    ImageEncoder newEncoder() const;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 };
 
 }
 
-#endif /* _OPENCV_PAM_HPP_ */
\ No newline at end of file
+#endif /* _OPENCV_PAM_HPP_ */
diff --git a/modules/imgcodecs/src/grfmt_png.hpp b/modules/imgcodecs/src/grfmt_png.hpp
index 3a3d004ffd..3d8d1a764a 100644
--- a/modules/imgcodecs/src/grfmt_png.hpp
+++ b/modules/imgcodecs/src/grfmt_png.hpp
@@ -51,18 +51,18 @@
 namespace cv
 {
 
-class PngDecoder : public BaseImageDecoder
+class PngDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     PngDecoder();
     virtual ~PngDecoder();
 
-    bool  readData( Mat& img );
-    bool  readHeader();
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
     void  close();
 
-    ImageDecoder newDecoder() const;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
 
@@ -78,16 +78,16 @@ protected:
 };
 
 
-class PngEncoder : public BaseImageEncoder
+class PngEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     PngEncoder();
     virtual ~PngEncoder();
 
-    bool  isFormatSupported( int depth ) const;
-    bool  write( const Mat& img, const std::vector<int>& params );
+    bool  isFormatSupported( int depth ) const CV_OVERRIDE;
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
 
-    ImageEncoder newEncoder() const;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 
 protected:
     static void writeDataToBuf(void* png_ptr, uchar* src, size_t size);
diff --git a/modules/imgcodecs/src/grfmt_pxm.hpp b/modules/imgcodecs/src/grfmt_pxm.hpp
index 3c7100b7d8..b4d5ad08fa 100644
--- a/modules/imgcodecs/src/grfmt_pxm.hpp
+++ b/modules/imgcodecs/src/grfmt_pxm.hpp
@@ -57,20 +57,20 @@ enum PxMMode
     PXM_TYPE_PPM = 3  // color format
 };
 
-class PxMDecoder : public BaseImageDecoder
+class PxMDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     PxMDecoder();
-    virtual ~PxMDecoder();
+    virtual ~PxMDecoder() CV_OVERRIDE;
 
-    bool  readData( Mat& img );
-    bool  readHeader();
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
     void  close();
 
-    size_t signatureLength() const;
-    bool checkSignature( const String& signature ) const;
-    ImageDecoder newDecoder() const;
+    size_t signatureLength() const CV_OVERRIDE;
+    bool checkSignature( const String& signature ) const CV_OVERRIDE;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
 
@@ -82,16 +82,16 @@ protected:
     int             m_maxval;
 };
 
-class PxMEncoder : public BaseImageEncoder
+class PxMEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     PxMEncoder(PxMMode mode);
-    virtual ~PxMEncoder();
+    virtual ~PxMEncoder() CV_OVERRIDE;
 
-    bool  isFormatSupported( int depth ) const;
-    bool  write( const Mat& img, const std::vector<int>& params );
+    bool  isFormatSupported( int depth ) const CV_OVERRIDE;
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
 
-    ImageEncoder newEncoder() const
+    ImageEncoder newEncoder() const CV_OVERRIDE
     {
         return makePtr<PxMEncoder>(mode_);
     }
diff --git a/modules/imgcodecs/src/grfmt_sunras.hpp b/modules/imgcodecs/src/grfmt_sunras.hpp
index ef09f9b1f9..ecd5c743fc 100644
--- a/modules/imgcodecs/src/grfmt_sunras.hpp
+++ b/modules/imgcodecs/src/grfmt_sunras.hpp
@@ -64,18 +64,18 @@ enum SunRasMapType
 
 
 // Sun Raster Reader
-class SunRasterDecoder : public BaseImageDecoder
+class SunRasterDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     SunRasterDecoder();
-    virtual ~SunRasterDecoder();
+    virtual ~SunRasterDecoder() CV_OVERRIDE;
 
-    bool  readData( Mat& img );
-    bool  readHeader();
+    bool  readData( Mat& img ) CV_OVERRIDE;
+    bool  readHeader() CV_OVERRIDE;
     void  close();
 
-    ImageDecoder newDecoder() const;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
 
@@ -89,15 +89,15 @@ protected:
 };
 
 
-class SunRasterEncoder : public BaseImageEncoder
+class SunRasterEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     SunRasterEncoder();
-    virtual ~SunRasterEncoder();
+    virtual ~SunRasterEncoder() CV_OVERRIDE;
 
-    bool write( const Mat& img, const std::vector<int>& params );
+    bool write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
 
-    ImageEncoder newEncoder() const;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 };
 
 }
diff --git a/modules/imgcodecs/src/grfmt_tiff.hpp b/modules/imgcodecs/src/grfmt_tiff.hpp
index eb0756f4d6..cd1b55ed02 100644
--- a/modules/imgcodecs/src/grfmt_tiff.hpp
+++ b/modules/imgcodecs/src/grfmt_tiff.hpp
@@ -90,20 +90,20 @@ enum TiffFieldType
 
 
 // libtiff based TIFF codec
-class TiffDecoder : public BaseImageDecoder
+class TiffDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
     TiffDecoder();
-    virtual ~TiffDecoder();
+    virtual ~TiffDecoder() CV_OVERRIDE;
 
-    bool  readHeader();
-    bool  readData( Mat& img );
+    bool  readHeader() CV_OVERRIDE;
+    bool  readData( Mat& img ) CV_OVERRIDE;
     void  close();
-    bool  nextPage();
+    bool  nextPage() CV_OVERRIDE;
 
-    size_t signatureLength() const;
-    bool checkSignature( const String& signature ) const;
-    ImageDecoder newDecoder() const;
+    size_t signatureLength() const CV_OVERRIDE;
+    bool checkSignature( const String& signature ) const CV_OVERRIDE;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
     void* m_tif;
@@ -119,19 +119,19 @@ private:
 };
 
 // ... and writer
-class TiffEncoder : public BaseImageEncoder
+class TiffEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     TiffEncoder();
-    virtual ~TiffEncoder();
+    virtual ~TiffEncoder() CV_OVERRIDE;
 
-    bool isFormatSupported( int depth ) const;
+    bool isFormatSupported( int depth ) const CV_OVERRIDE;
 
-    bool  write( const Mat& img, const std::vector<int>& params );
+    bool  write( const Mat& img, const std::vector<int>& params ) CV_OVERRIDE;
 
-    bool writemulti(const std::vector<Mat>& img_vec, const std::vector<int>& params);
+    bool writemulti(const std::vector<Mat>& img_vec, const std::vector<int>& params) CV_OVERRIDE;
 
-    ImageEncoder newEncoder() const;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 
 protected:
     void  writeTag( WLByteStream& strm, TiffTag tag,
diff --git a/modules/imgcodecs/src/grfmt_webp.hpp b/modules/imgcodecs/src/grfmt_webp.hpp
index ea692bf8d2..79e041b212 100644
--- a/modules/imgcodecs/src/grfmt_webp.hpp
+++ b/modules/imgcodecs/src/grfmt_webp.hpp
@@ -52,36 +52,36 @@
 namespace cv
 {
 
-class WebPDecoder : public BaseImageDecoder
+class WebPDecoder CV_FINAL : public BaseImageDecoder
 {
 public:
 
     WebPDecoder();
-    ~WebPDecoder();
+    ~WebPDecoder() CV_OVERRIDE;
 
-    bool readData( Mat& img );
-    bool readHeader();
+    bool readData( Mat& img ) CV_OVERRIDE;
+    bool readHeader() CV_OVERRIDE;
     void close();
 
-    size_t signatureLength() const;
-    bool checkSignature( const String& signature) const;
+    size_t signatureLength() const CV_OVERRIDE;
+    bool checkSignature( const String& signature) const CV_OVERRIDE;
 
-    ImageDecoder newDecoder() const;
+    ImageDecoder newDecoder() const CV_OVERRIDE;
 
 protected:
     Mat data;
     int channels;
 };
 
-class WebPEncoder : public BaseImageEncoder
+class WebPEncoder CV_FINAL : public BaseImageEncoder
 {
 public:
     WebPEncoder();
-    ~WebPEncoder();
+    ~WebPEncoder() CV_OVERRIDE;
 
-    bool write(const Mat& img, const std::vector<int>& params);
+    bool write(const Mat& img, const std::vector<int>& params) CV_OVERRIDE;
 
-    ImageEncoder newEncoder() const;
+    ImageEncoder newEncoder() const CV_OVERRIDE;
 };
 
 }
diff --git a/modules/imgcodecs/src/loadsave.cpp b/modules/imgcodecs/src/loadsave.cpp
index 814d307748..c2042b8ae9 100644
--- a/modules/imgcodecs/src/loadsave.cpp
+++ b/modules/imgcodecs/src/loadsave.cpp
@@ -89,7 +89,7 @@ public:
 protected:
     virtual pos_type seekoff( off_type offset,
                               std::ios_base::seekdir dir,
-                              std::ios_base::openmode )
+                              std::ios_base::openmode ) CV_OVERRIDE
     {
         char* whence = eback();
         if (dir == std::ios_base::cur)