HDR Assessment & Evaluation Techniques 2 — Questions and Answers
Question 1: Which metric is used to evaluate the maximum light level of an entire HDR frame, averaged across all bright pixels?
- MaxCLL
- MaxFALL (Correct answer)
- EOTF
- OOTF
Correct answer: MaxFALL
MaxFALL (Maximum Frame Average Light Level) represents the highest average luminance of any single frame in a content piece.
Question 2: When performing a subjective evaluation of HDR content, what viewing environment condition is most critical to control?
- Room temperature
- Ambient light level (Correct answer)
- Screen size
- Viewer distance from display
Correct answer: Ambient light level
Ambient light level directly affects perceived contrast and must be controlled to ITU-R BT.2100 recommendations for valid HDR evaluation.
Question 3: In HDR quality control, which EOTF is specifically used for broadcast and streaming HDR applications alongside SDR compatibility?
- PQ (ST 2084)
- HLG (Hybrid Log-Gamma) (Correct answer)
- Gamma 2.4
- sRGB
Correct answer: HLG (Hybrid Log-Gamma)
HLG was designed for broadcast to maintain backward compatibility with SDR displays while supporting HDR viewing.
Question 4: What is the primary purpose of a test pattern showing a 5% white window on a black field during HDR display assessment?
- Evaluate color accuracy
- Measure peak luminance under realistic load conditions (Correct answer)
- Check gamma curve linearity
- Assess black level uniformity
Correct answer: Measure peak luminance under realistic load conditions
A 5% white window on black simulates realistic peak highlights and tests how well a display sustains peak luminance without thermal throttling.
Question 5: Which tool is considered the industry standard for objective measurement of display luminance in HDR evaluation?
- Spectroradiometer (Correct answer)
- Colorimeter
- Oscilloscope
- Vectorscope
Correct answer: Spectroradiometer
A spectroradiometer measures absolute luminance and color with high accuracy, making it the reference instrument for HDR display calibration and evaluation.
Question 6: During HDR mastering review, what does a 'clipping' artifact in the luminance channel indicate?
- The image is too dark
- Highlight detail is lost because luminance exceeds the mastering display ceiling (Correct answer)
- Color saturation is incorrect
- The frame rate is inconsistent
Correct answer: Highlight detail is lost because luminance exceeds the mastering display ceiling
Clipping occurs when luminance values exceed the mastering display's peak capability, permanently losing highlight detail in the final deliverable.
Question 7: When evaluating an HDR10 deliverable, which static metadata fields are mandatory per the SMPTE ST 2086 specification?
- MaxCLL and MaxFALL only
- Display primaries, white point, min/max luminance of mastering display (Correct answer)
- ColorSpace and bit depth only
- EOTF type and peak nit value
Correct answer: Display primaries, white point, min/max luminance of mastering display
SMPTE ST 2086 requires the mastering display color primaries, white point, and min/max luminance to be embedded as static HDR metadata.
HDR Assessment & Evaluation Techniques 2
Which metric is used to evaluate the maximum light level of an entire HDR frame, averaged across all bright pixels?