Metric fitting results

This is the proposed metric described in detail in the paper "HDR-VDP-2: A calibrated visual metric for visibility and quality predictions in all luminance conditions" (doi). It shares many similarities with VDP'93 and HDR-VDP, as it was inspired by these metrics, but the functionality is much extended and individual components are thoroughly revised. The major differences are:

• The metric predicts both visibility (detection/decrimination) and image quality (mean-opinion-score).
• The metric is based on new CSF measurements, made in the consistent viewing conditions for a large range of luminance and frequency.
• The new metric models L-, M-, S- and rod sensitivities and is sensitive to different spectral characteristic of the incoming light.
• Photoreceptor light sensitivity is modelled separately for cones and rods, though L and M cones share the same characteristic.
• The intra-ocular light scatter function (glare) has been fitted to the experimental data.
• The model used a steerable pyramid rather than cortex transform to decompose image into spatially- and orientation-selective bands. Steerable filter introduces less ringing and in general case is computationally more efficient.
• The new model of contrast masking introduces inter-band masking and the effect of CSF flattening.
• A simple spatial-integration formula using probability summation is used to account for the effect of stimuli size.