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/npr_demo.cpp

@@ -38,7 +38,7 @@ int main(int argc, char* argv[])
 
     Mat I = imread(argv[1]);
 
-    if(!I.data)
+    if(I.empty())
     {
         cout <<  "Image not found" << endl;
         exit(0);