Image overlays
| Operation | Syntax |
|---|---|
| Image overlay | -/overlay/:uuid/ -/overlay/:uuid/:rel_dimensions/:rel_coords/:opacity/ |
| Self overlay | -/overlay/self/ -/overlay/self/:rel_dimensions/:rel_coords/:opacity/ |
| Text overlay | -/text/:rel_dimensions/:rel_coords/:text/ |
| Color overlay | -/rect/:color/:relative_dimensions/:relative_coordinates/ |
