Several type of formal refactoring:

1. someMatrix.data -> someMatrix.prt()
2. someMatrix.data + someMatrix.step * lineIndex -> someMatrix.ptr( lineIndex )
3. (SomeType*) someMatrix.data -> someMatrix.ptr<SomeType>()
4. someMatrix.data -> !someMatrix.empty() ( or !someMatrix.data -> someMatrix.empty() ) in logical expressions

samples/cpp/image.cpp

@@ -48,7 +48,7 @@ int main( int argc, char** argv )
     }
 #endif
 
-    if( !img.data ) // check if the image has been loaded properly
+    if( img.empty() ) // check if the image has been loaded properly
         return -1;
 
     Mat img_yuv;