Changed to ctrl+d since it's easier to press.

tools/imglab/src/metadata_editor.cpp

@@ -336,7 +336,7 @@ on_keydown (
             last_keyboard_jump_pos_update = 0;
         }
 
-        if (key == 'r' && (state&base_window::KBD_MOD_CONTROL))
+        if (key == 'd' && (state&base_window::KBD_MOD_CONTROL))
         {
             remove_selected_images();
         }
@@ -578,7 +578,7 @@ display_about(
                         "a rectangle selects it and the delete key removes it.  You can also mark "
                         "a rectangle as ignored by hitting the i key when it is selected.  Ignored "
                         "rectangles are visually displayed with an X through them.  You can remove an image "
-                        "entirely by selecting it in the list on the left and pressing ctrl+r."
+                        "entirely by selecting it in the list on the left and pressing ctrl+d."
                         ,0,0) << endl << endl;
 
     sout << wrap_string("It is also possible to label object parts by selecting a rectangle and "