Addressing #341 #342 and #343 #345
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| can be derived from cICP chunk formats. Specific examples of its most common use-cases | ||
| for both HDR and SDR are available in [[ITU-T-Series-H-Supplement-19]].</p> | ||
| on its inherent capabilities. The mDCv chunk should be included for PQ | ||
| images. It is less common for other image formats but may be included. Color Primaries and White Point characteristics |
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Do we have any other examples besides absolute luminance, display-referred, BT.2100 PQ?
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I believe @chrisn was aware of cases where mDCv is useful in SDR cases. Chris Needham, can you confirm?
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I'm not sure that was me ... perhaps @digitaltvguy?
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Oh, you're right. Sorry.
| @@ -3898,7 +3934,7 @@ <h2><span class="chunk">mDCv</span> Mastering Display Color Volume</h2> | |||
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| <aside class="example"> | |||
| Example <span class="chunk">mDCv</span> chunk mastering display maximum | |||
| luminance using traditional SDR shading techniques at 100 cd/m<sup>2</sup> | |||
| luminance using traditional live television production techniques at 100 cd/m<sup>2</sup> | |||
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This is okay as it is just an example, not a list of all use cases.
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| <p>A value of zero for either MaxCLL or MaxFALL means that the value is unknown or not currently calculable.</p> | ||
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| <p class="note">An example where this will not be calculable is when creating a live animated PNG stream, when not all frames will be available to compute the values until the stream ends. The encoder may wish to use the value zero initially and replace this with the calculated value when the stream ends.</p> |
| <dt id="3pq"><dfn>high dynamic range (HDR)</dfn> | ||
| </dt> | ||
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| <dd> | ||
| an image format capable of storing images with a relatively low dynamic range of 5-8 stops. Examples include sRGB, Display P3, ITU-R BT.709 | ||
| </dd> |
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1.) I would prefer new IDs to not include the section number.
2.) The ID ("pq") doesn't match the term ("HDR") which doesn't match the definition ("low dynamic range"). Was this supposed to be a definition of SDR?
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| <dd> | ||
| <a>transfer function</a> defined in ITU-R BT.2100 Table 5. (A relative scene-referred system) |
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Can "ITU-R BT.2100 Table 5" be a link to the standard?
| <dt id="3sdr"><dfn>standard dynamic range (SDR)</dfn> | ||
| </dt> | ||
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| <dd> | ||
| an image format capable of storing images with a relatively high dynamic range similar to or in excess of the human visual system's instantaneous dynamic range (~12-14 stops). PNG allows the use of 2 HDR formats, HLG and PQ. | ||
| </dd> |
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The term ("SDR") doesn't match the description ("high dynamic range").
I'm guessing this was meant to be a definition of HDR.
| <dt id="3stop"><dfn>stop</dfn> | ||
| </dt> |
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Small formatting difference here of whitespace.
| can be derived from cICP chunk formats. Specific examples of its most common use-cases | ||
| for both HDR and SDR are available in [[ITU-T-Series-H-Supplement-19]].</p> | ||
| on its inherent capabilities. The mDCv chunk should be included for PQ | ||
| images. It is less common for other image formats but may be included. Color Primaries and White Point characteristics |
There was a problem hiding this comment.
I believe @chrisn was aware of cases where mDCv is useful in SDR cases. Chris Needham, can you confirm?
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Oh, it looks like many of the things I mentioned are fixed in #348 |
Once we're happy with the text, still need to: