- From: Chris Blume (ProgramMax) <programmax@gmail.com>
- Date: Wed, 6 Dec 2023 17:21:08 -0500
- To: "Seeger, Chris (NBCUniversal)" <Chris.Seeger@nbcuni.com>
- Cc: "Portable Network Graphics (PNG) Working Group" <public-png@w3.org>
- Message-ID: <CAG3W2KeseOosmaQsdUZJ0G_Q+N3E3p1D_03isENx+x6H=TgyNA@mail.gmail.com>
I just realized I could pre-make a bunch of common CICP files for us. The vast majority of our usage will be: SDR (narrow & full) HLG (narrow & full) PQ (full) Display-P3 (full) Right? That probably covers the bulk of use cases. And it's only 6 files. On Wed, Dec 6, 2023 at 5:11 PM Chris Blume (ProgramMax) < programmax@gmail.com> wrote: > Attached are the 5 images with the CICP values you provided. I changed the > file names so the "NoCICP" part is now just "CICP". > > I'm also attaching a file named cicp.chunk. This simplifies if we want to > add cICP chunks to other PNGs in the future. Here is how: > The cicp.chunk file has the CICP values 0-0-0-0. You can use a hex editor > like HexEd.it to open the cicp.chunk file and change the last 4 bytes to > different CICP values. Save your changes. > Then, with TweakPNG <https://entropymine.com/jason/tweakpng/>, you can > use the menu Edit -> Import Chunk... and select the cicp.chunk file. This > will add the cICP chunk to the PNG you have open. > > It is a bit of a pain to need to manually edit the cicp.chunk file every > time. But the benefit of using this approach is you don't need to manually > compute the chunk's CRC values, since TweakPNG will add them for you. > Also, since this process is a pain I'm happy to do this for people in the > future. > > Hope this helps :D > > > > On Wed, Dec 6, 2023 at 1:57 PM Seeger, Chris (NBCUniversal) < > Chris.Seeger@nbcuni.com> wrote: > >> I haven’t made contact with Pixelmator folks yet. But here are the >> Affinity Folks. >> >> >> >> I’m corresponding with: >> >> >> >> Andy Somerfield asomerfield@serif.com (dev) >> >> John Atkin john@serif.com (PR) >> >> >> >> This is what Andy shared so far: >> >> >> >> Internally, Photo manipulates HDR content as ICC profiled, linear 32bit >> floating point data. Conversion from PQ / HLG is dealt with at import time >> (for example, a PQ encoded HEIF from a Canon camera will be converted to >> Linear sRGB). >> >> >> >> All compositing is then done in a linear colour space and we support a >> number of clipping visualisation options as well as native HDR display >> (which is presently a bit better on Mac than Windows - Apple’s approach to >> HDR display is the right approach, but others are yet to properly copy it). >> A large number of (nearly all) Photo features work properly in 32bit HDR - >> aside from the obvious (Invert, etc. where there is no logical “Maximum”). >> >> >> >> We currently do not support encoding to PQ / HLG at export time - >> although it’s something we are actively looking to do. I guess we are >> waiting for the format war to conclude (or rather, to begin..) >> >> >> >> Our 32bit compositing pipeline was developed primarily for VFX users - so >> our EXR round-trip stuff is pretty good - but that’s not what you’re >> looking for, I assume. >> >> >> >> -Chris >> >> >> >> >> >> *From: *Chris Blume (ProgramMax) <programmax@gmail.com> >> *Date: *Wednesday, December 6, 2023 at 1:45 PM >> *To: *Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com> >> *Cc: *Portable Network Graphics (PNG) Working Group <public-png@w3.org> >> *Subject: *Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709? >> >> Do we have contacts at either of those two companies? >> >> >> >> On Wed, Dec 6, 2023 at 12:39 PM Seeger, Chris (NBCUniversal) < >> Chris.Seeger@nbcuni.com> wrote: >> >> Thanks so much 😊. This will move us forward more quickly. >> >> >> >> Two new apps to test that might be worth some more investigation: >> >> >> >> Photomator >> >> https://apps.apple.com/us/app/photomator-photo-editor/id1444636541 >> <https://urldefense.com/v3/__https:/apps.apple.com/us/app/photomator-photo-editor/id1444636541__;!!PIZeeW5wscynRQ!p_ez9avjNcZUjumErOtECBA-lsR2cn4LVb2Y1Z2g_SZ18aSceD1onLjF28JZsu_85wsz__0QELd90TshvzdG$> >> >> >> >> Affinity Photo >> >> https://apps.apple.com/us/app/affinity-photo-2/id1616822987?mt=12 >> <https://urldefense.com/v3/__https:/apps.apple.com/us/app/affinity-photo-2/id1616822987?mt=12__;!!PIZeeW5wscynRQ!p_ez9avjNcZUjumErOtECBA-lsR2cn4LVb2Y1Z2g_SZ18aSceD1onLjF28JZsu_85wsz__0QELd90REW-68w$> >> >> >> >> >> >> Best, >> >> Chris >> >> >> >> *From: *Chris Blume (ProgramMax) <programmax@gmail.com> >> *Date: *Wednesday, December 6, 2023 at 11:52 AM >> *To: *Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com> >> *Cc: *Portable Network Graphics (PNG) Working Group <public-png@w3.org> >> *Subject: *Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709? >> >> Simon is right. >> I'll work on adding cICP chunks now. >> >> >> >> On Wed, Dec 6, 2023 at 11:11 AM Seeger, Chris (NBCUniversal) < >> Chris.Seeger@nbcuni.com> wrote: >> >> Yes. They are public. Can we start with cicp only as they are not >> required for PQ, HLG or SDR? >> >> >> >> If you show me how to do it, and with what tools, maybe I can help. >> >> >> >> Best, >> >> Chris >> >> >> >> Get Outlook for iOS >> <https://urldefense.com/v3/__https:/aka.ms/o0ukef__;!!PIZeeW5wscynRQ!uLCseTAx_Hyxx7ImY4JuTY9ZQE6yQqk9WuV4Jp7w5pOovkCOED_tSs63dlwwyry1KgwghWlvJWWUJ5s7UYwx$> >> ------------------------------ >> >> *From:* Chris Blume (ProgramMax) <programmax@gmail.com> >> *Sent:* Wednesday, December 6, 2023 10:37:11 AM >> *To:* Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com> >> *Cc:* Portable Network Graphics (PNG) Working Group <public-png@w3.org> >> *Subject:* [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709? >> >> >> >> I can hexedit in cICP values. >> >> Although, maybe I should wait until we have mDCv and cLLi values as well? >> How long do you think it would take to get those values? >> >> My thought is: I don't want to start distributing test images only to >> later tell people to use these new test images instead (when they don't yet >> have a way to see which ones are new/old). >> But maybe it will take a while to get mDCv and cLLi values. So maybe it >> would be good to get some new test images sooner? >> >> (Are these images public domain? Can we distribute them widely?) >> >> >> >> On Wed, Dec 6, 2023 at 8:53 AM Seeger, Chris (NBCUniversal) < >> Chris.Seeger@nbcuni.com> wrote: >> >> Hi Chris and All, >> >> >> >> Do we have any conformance files in each format (PQ, HLG, SDR-BT.709)? >> I’ve got a number of developers who’d like to add the functionality into >> their apps. Once of them requested test files. >> >> >> >> I’ve created test files if someone can add cICp chunks to them: >> >> >> >> >> https://www.dropbox.com/scl/fo/a44vfxw3p21kvkh8nywpc/h?rlkey=v63ekq5y49kd4omg59ng9q3zr&dl=0 >> <https://urldefense.com/v3/__https:/www.dropbox.com/scl/fo/a44vfxw3p21kvkh8nywpc/h?rlkey=v63ekq5y49kd4omg59ng9q3zr&dl=0__;!!PIZeeW5wscynRQ!u3P4S_qNlSUgxiBGGql3lAci2mnjiYXwiMFO_BJmTverJdmVa01jIZup7LNb0VmqqIefc7ZiC_qDHR576Lqb$> >> >> >> >> SDR CICP: 1-1-1 (Narrow and Full Range versions marked NR or FR) >> >> PQ CICP: 9-16-9 (Full Range only as there is no benefit to NR PQ) >> >> HLG CICP: 9-18-9 (Narrow and Full Range versions marked NR or FR) >> >> >> >> I will send mDCv and cLLI values (just an example at a later date since >> cICp is most important to get to developers). >> >> >> >> Thanks very much, >> >> >> >> *Chris Seeger* >> >> Director, Advanced Content Production >> >> Office of the CTO >> >> C: 551-238-3768 >> >> [image: signature_856391991] >> >> >> >>
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Received on Wednesday, 6 December 2023 22:21:28 UTC