mDCv and cLLi are now mDCV and cLLI

[svgeesus]

Because these chunks are unsafe-to-copy, the chunk names were changed:

• mDCV Mastering Display Color Volume
• cLLI Content Light Level Information

No change to the contents of these chunks.

[ProgramMax]

I see this support cICP from Third Edition. But I don't think it support mDCV or cLLI yet, right?
So to clarify, I think the request isn't to catch up to the renaming--it's to preemptively add them as mDCV and cLLI instead of mDCv and cLLi when they do get implemented.

[tleguern]

Hello. Chunks mDCV and cLLI have never been implemented regardless of capitalisation. I never encountered a file containing either of them yet and frankly don't really understand what they do.

[ProgramMax]

I'm not a color expert so I'll try to answer to the best of my knowledge but take what I say with a grain of salt.

mDCV and cLLI provide information for the final display to apply tone mapping.
As an example, the image doesn't know the final display's capabilities. So maybe the image stores colors and brightness that the display can't handle. Tone mapping allows the display to bring things within its capabilities while still preserving important details for its intended viewing.

Like if we just darken all colors, maybe an important clue becomes too dim. So a flat or linear dark won't work. Maybe we need a curve or steps. The display knows how much processing power it has, its capabilities, and this content information -- thus what tone mapping algorithm is the best fit.