int main (int argc, const char *argv[]) {

  if(argc < 2) {

    cout << "Drag and drop files to the exe" << endl;
    cin.get();
    return 0;

  } else {

    string line;
    for(int i = 1; i < argc; i++) {
      cout << "> load image from: " << argv[i] << endl;
    }

  }

}

Drag and Drop onto Exe to execute

C++