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

 Very easy to fix now that I have these .chunk files :D
Attached are the updated PNG test files using zero as the matrix
coefficient.

Also attached are all the .chunk files I used.
I also am attaching a Display P3 Full .chunk file and a sRGB Full .chunk
file. I did not apply these to any images. If you happen to have test
images for those, I'll add them.

On Wed, Dec 6, 2023 at 6:14 PM Seeger, Chris (NBCUniversal) <
Chris.Seeger@nbcuni.com> wrote:

> Thanks.  I made a mistake.  The matrix coefficients should have been “0”
> because we are RGB (not YCbCr).
>
>
>
> MediaArea folks already detected this also.
>
>
>
> Is this easy to fix?
>
>
>
> -Chris
>
>
>
> *From: *Chris Blume (ProgramMax) <programmax@gmail.com>
> *Date: *Wednesday, December 6, 2023 at 6:08 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?
>
> 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]
>
>
>
>