HDR Standards & Tone Mapping Flashcards

In PQ (SMPTE ST 2084) calibration, what luminance level represents diffuse (reference) white?

Answer: 203 nits

In PQ/HDR10 content, diffuse white is encoded at approximately 203 nits, providing luminance headroom above reference white for specular highlights.

What is 'clipping' in the context of HDR tone mapping?

Answer: Loss of highlight detail when content luminance exceeds the display's peak capability

Clipping occurs when HDR content specifies a luminance level beyond what the display can output, causing bright highlights to be rendered without detail.

What luminance value does code value 0 represent in SMPTE ST 2084 (PQ)?

Answer: 0 nits (absolute black)

In ST 2084, code value 0 maps to 0 nits (absolute black), with the PQ curve providing perceptually uniform encoding all the way to this minimum.

When evaluating HDR display performance for ISF calibration, which pair of measurements is most critical?

Answer: Both peak white and black level to calculate dynamic range

ISF HDR evaluation requires measuring both peak luminance and black level to fully characterize the display's dynamic range and native contrast ratio.

What is the minimum peak luminance requirement for an LCD-type display to achieve UHD Alliance 'Ultra HD Premium' certification?

Answer: 1,000 nits

The UHD Alliance requires LCD-based displays to reach at least 1,000 nits peak luminance with a black level at or below 0.05 nits for Ultra HD Premium certification.

What primary advantage does Dolby Vision's 12-bit processing offer over HDR10's 10-bit processing?

Answer: Greater tonal precision with fewer banding artifacts in smooth gradients

Dolby Vision's 12-bit depth provides four times more tonal steps than HDR10's 10-bit, significantly reducing visible banding in smooth luminance or color transitions.

In tone mapping, what does 'roll-off' refer to when approaching a display's peak luminance?

Answer: The gradual, smooth compression of highlights to preserve detail rather than hard clipping

Roll-off is the technique of gradually compressing highlight luminance as it approaches the display's peak, preserving more highlight detail than abrupt hard clipping.