Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?

(Oh, the files are already named "SDR-BT.709" and not just "SDR". So the
file names are fine.)

On Wed, Dec 6, 2023 at 6:07 PM Chris Blume (ProgramMax) <
programmax@gmail.com> wrote:

> I'm creating those .chunk files now.
> But I realized a potential mistake I made in the batch of 5 images I sent
> you.
>
> You provided the correct CICP values and I blindly copied them. However,
> they need to be adapted for PNG.
> PNG currently only supports the identity matrix. So the third field should
> always be 0.
>
> Values I used:
> SDR CICP: 1-1-1
> PQ CICP: 9-16-9
> HLG CICP: 9-18-9
>
> Values I should have used:
> SDR CICP: 1-1-0
> PQ CICP: 9-16-0
> HLG CICP: 9-18-0
>
> (Also, I want to rename the file from "SDR" to "BT709". I'll also create
> an sRGB file.)
>
> Will these CICP values be a problem for your testing? Should we revisit
> the CICP chunk to allow non-zero matrix coefficients?
>
>
> On Wed, Dec 6, 2023 at 5:42 PM Seeger, Chris (NBCUniversal) <
> Chris.Seeger@nbcuni.com> wrote:
>
>> I’ve sent the example files to MediaArea to see if they can add detection
>> to MediaInfo.
>>
>>
>>
>> *From: *Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com>
>> *Date: *Wednesday, December 6, 2023 at 5:41 PM
>> *To: *Chris Blume (ProgramMax) <programmax@gmail.com>
>> *Cc: *Portable Network Graphics (PNG) Working Group <public-png@w3.org>
>> *Subject: *Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?
>>
>> Hi Chris,
>>
>>
>>
>> Do you have the raw cicp.chunk files with each value (of the 6
>> variations).  We can use them to change future files.
>>
>>
>>
>> Thx.
>>
>>
>>
>> *From: *Chris Blume (ProgramMax) <programmax@gmail.com>
>> *Date: *Wednesday, December 6, 2023 at 5:12 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?
>>
>> 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
>> <https://urldefense.com/v3/__http:/HexEd.it__;!!PIZeeW5wscynRQ!ojwrBR6jR3-svspWLLmi1N_ZGz0nu2iGkJRX82x3p2CR9ElYZ4ANFsR04-MBHxq5KizMxgWA4AwDvSxkTFCy$>
>> to open the cicp.chunk file and change the last 4 bytes to different CICP
>> values. Save your changes.
>>
>> Then, with TweakPNG
>> <https://urldefense.com/v3/__https:/entropymine.com/jason/tweakpng/__;!!PIZeeW5wscynRQ!ojwrBR6jR3-svspWLLmi1N_ZGz0nu2iGkJRX82x3p2CR9ElYZ4ANFsR04-MBHxq5KizMxgWA4AwDvZ-Skuci$>,
>> 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]
>>
>>
>>
>>