DualHead-HF's symmetric architecture includes two independent overlay controllers and programmable mixing engines. Each overlay controller is equipped with a scalar unit and a look-up table (LUT) for gamma-corrected overlays. Video has a gamma curve different from RGB data found on the desktop. Therefore, it needs to be corrected independently of the primary display to produce an accurate color output.
Dual mixing engines enable various blending options of the primary surface with the overlay surface. These mixing engines support 256 levels of alpha-keying with per-pixel independent alpha support, as well as chroma and color keying on a per-component range.