ISF HDR Standards & Tone Mapping 2 — Questions and Answers
Question 1: What key feature distinguishes Dolby Vision from HDR10?
- Higher peak luminance support
- Dynamic metadata updated per scene or frame (Correct answer)
- Wider color gamut coverage
- Lower bandwidth requirements
Correct answer: Dynamic metadata updated per scene or frame
Dolby Vision uses dynamic metadata that can be adjusted per scene or per frame, enabling precise tone mapping for every moment of content.
Question 2: What is the primary purpose of tone mapping in HDR content delivery?
- To convert SDR content to HDR
- To adapt HDR content for displays with lower peak luminance capability (Correct answer)
- To increase color saturation in highlights
- To correct gamma curve errors
Correct answer: To adapt HDR content for displays with lower peak luminance capability
Tone mapping compresses the HDR luminance range to fit within the output capabilities of a specific display, preserving as much visible detail as possible.
Question 3: What color gamut container is specified for HDR10 color primaries?
- sRGB (BT.709)
- DCI-P3
- BT.2020 (Correct answer)
- AdobeRGB
Correct answer: BT.2020
HDR10 uses BT.2020 as its color container, though most content is mastered within the DCI-P3 subset of that gamut.
Question 4: What does MaxFALL (Maximum Frame Average Light Level) measure in HDR10 metadata?
- The peak luminance of the mastering display
- The average luminance across the entire program
- The maximum average luminance value of any single frame (Correct answer)
- The minimum frame luminance in the content
Correct answer: The maximum average luminance value of any single frame
MaxFALL specifies the highest average luminance value (averaging all pixels) found in any single frame throughout the content.
Question 5: HDR10+ was developed as a royalty-free alternative to Dolby Vision. Who created it?
- Dolby Laboratories
- Samsung and Amazon Video (Correct answer)
- BBC and NHK
- Sony and Netflix
Correct answer: Samsung and Amazon Video
HDR10+ was developed by Samsung and Amazon Video as an open, royalty-free dynamic metadata HDR format competing with Dolby Vision.
Question 6: How does the HLG transfer function achieve backward compatibility with SDR displays?
- It uses PQ encoding — compatible via firmware update
- Its lower signal portion follows a gamma curve matching SDR, while the upper portion uses a logarithmic curve (Correct answer)
- It embeds an SDR downconvert track alongside the HDR signal
- It uses linear transfer — needs no conversion
Correct answer: Its lower signal portion follows a gamma curve matching SDR, while the upper portion uses a logarithmic curve
HLG uses a hybrid curve where the lower portion matches a standard gamma curve (SDR-compatible), while the upper portion uses a logarithmic extension for HDR highlights.
Question 7: What is the nominal reference white luminance level for HLG broadcast signals?
- 100 nits
- 203 nits (Correct answer)
- 400 nits
- 1,000 nits
Correct answer: 203 nits
In HLG, the nominal reference white corresponds to approximately 203 nits, roughly double the 100-nit SDR reference white convention.
ISF HDR Standards & Tone Mapping 2
What key feature distinguishes Dolby Vision from HDR10?