- From: Robb Beal <robb@veriskope.com>
- Date: Mon, 10 May 2021 13:54:54 -0500
- To: Lars Borg <borg@adobe.com>
- Cc: Pierre-Anthony Lemieux <pal@sandflow.com>, Christopher Cameron <ccameron@google.com>, Chris Lilley <chris@w3.org>, "public-colorweb@w3.org" <public-colorweb@w3.org>
- Message-ID: <CAGrL5eGKgvT3f9YK4gKwYyTBG8ETnqmTbo3XSMxzUd2jZtkiUw@mail.gmail.com>
> > Do image browsers/editors use canvas? The Google Photos editor does. On Mon, May 10, 2021 at 1:41 PM Lars Borg <borg@adobe.com> wrote: > Here is a simple use case. > Camera or other source delivers images with this kind of ICC profile. > Uploaded to Adobe Stock, Lightroom Web, Dropbox or Google or whatever. > User browses their image library, determines which images are OK vs crap. > Reasonable fidelity is needed, or else images will look like crap. > User edits image in image browser/editor. > Do image browsers/editors use canvas? > > Right now, ungraded HDR images come across as too dark in Lightroom Web. > Seems color management info is missing and it's read as SDR. > > Lars > > -----Original Message----- > From: Pierre Lemieux <pal@sandflow.com> > Date: Sunday, May 9, 2021 at 7:21 PM > To: Lars Borg <borg@adobe.com> > Cc: Christopher Cameron <ccameron@google.com>, Chris Lilley <chris@w3.org>, > "public-colorweb@w3.org" <public-colorweb@w3.org> > Subject: Re: ICC profile with headroom above SDR was: HTML Canvas - > Transforms for HDR and WCG > > Hi Lars, > > I am trying to understand if/how the existence of these images/ICC > profile combinations affect the Canvas API. It does not look like it > does, but maybe? > > I have added the topic to the agenda of our call on 2021-05-10. > > Best, > > -- Pierre > > > On Sat, May 8, 2021 at 6:49 PM Lars Borg <borg@adobe.com> wrote: > > > > If you have specific questions, that would help. > > > > -----Original Message----- > > From: Lars Borg <borg@adobe.com> > > Date: Saturday, May 8, 2021 at 3:49 PM > > To: Pierre Lemieux <pal@sandflow.com> > > Cc: Christopher Cameron <ccameron@google.com>, Chris Lilley < > chris@w3.org>, "public-colorweb@w3.org" <public-colorweb@w3.org> > > Subject: Re: ICC profile with headroom above SDR was: HTML Canvas - > Transforms for HDR and WCG > > > > You're asking for use cases. > > That will take more time to determine. > > > > -----Original Message----- > > From: Pierre Lemieux <pal@sandflow.com> > > Date: Friday, May 7, 2021 at 12:40 PM > > To: Lars Borg <borg@adobe.com> > > Cc: Christopher Cameron <ccameron@google.com>, Chris Lilley < > chris@w3.org>, "public-colorweb@w3.org" <public-colorweb@w3.org> > > Subject: ICC profile with headroom above SDR was: HTML Canvas - > Transforms for HDR and WCG > > > > Hi Lars, > > > > It is still not clear to me how these profiles are used and how the > > images are created. > > > > Couple of questions come to mind: > > > > - are the images created on an SDR or HDR display? > > > > - is the ICC profile applied while the image is created, i.e. is the > > author manipulating the results of the image after processing through > > the ICC profile? > > > > - in the case of a PNG file, is the image expected to be acceptable on > > an sRGB display without the ICC profile applied? > > > > Best, > > > > -- Pierre > > > > On Fri, May 7, 2021 at 12:15 AM Lars Borg <borg@adobe.com> wrote: > > > > > > In this context any ICC profile with headroom above SDR white is > applicable. > > > Adobe currently ships such profiles, all having a significant > headroom. Also attached. > > > This covers both cine camera profiles and HDR profiles. All are V4 > profiles. > > > AFAIK, there are more such profiles in the market place. > > > (Adobe started shipping such profiles in 2006) > > > > > > ARRI LogC3 Wide Color Gamut - El 160 > > > ARRI LogC3 Wide Color Gamut - El 1600 > > > ARRI LogC3 Wide Color Gamut - El 800 > > > Canon Cinema CLog2 > > > Canon Cinema CLog3 > > > e-sRGB > > > P3 D65 PQ W203 > > > P3 D65 PQ W300 > > > P3 PQ Display Full > > > Panasonic V-Gamut V-Log > > > Rec.2100 HLG Scene W63 > > > Rec.2100 HLG Scene W75 > > > Rec.2100 HLG Scene W81 > > > Rec.2100 HLG W100 > > > Rec.2100 HLG W203 > > > Rec.2100 HLG W300 > > > Rec.2100 PQ W100 > > > Rec.2100 PQ W203 > > > Rec.2100 PQ W300 > > > Rec.lTU-R BT.2100 HLG Scene Full > > > Rec.lTU-R BT.2100 HLG Scene Narrow > > > Rec.lTU-R BT.2100 PQ Display Full > > > Sony S-Gamut3.Cine/S-Log3 > > > Sony S-Gamut3/S-Log3 > > > Universal Camera Film Printing Density > > > > > > > > > A user can embed any of the above profiles in these file formats with > these extensions (using Photoshop). > > > Other tools can support other formats. > > > > > > psd Photoshop > > > psb Large Document Format > > > eps Photoshop EPS > > > jpg JPEG > > > jpf JPEG 2000 > > > jps JPEG Stereo > > > mpo Multi-Picture Format > > > pdf Photoshop PDF > > > png PNG > > > tif TIFF > > > > > > Not tested if these work with SVG. > > > > > > ICC profiles provide a color transform from RGB to XYZ D50. > > > ICC profiles do not provide colorimetry info in the style of an ISO > 22028 color image encoding specification. > > > These profiles do not do tone mapping, but preserve the headroom. > > > The relative colorimetric intent, present in all of these profiles, > together with the chad tag, provides colorimetric values for each RGB value. > > > A few of the profiles indicate scene-referred colorimetry. > > > A few of the profiles indicate nits for graphics white. > > > A few of the profiles contain the draft CICP tag. > > > > > > The ICC profile is embedded in the wrapper, not in the codec data > (AFAIK). > > > Besides the ICC profile, there is no colorimetry info in the files. > > > > > > Lars > > > > > > -----Original Message----- > > > From: Pierre Lemieux <pal@sandflow.com> > > > Date: Monday, May 3, 2021 at 5:07 AM > > > To: Lars Borg <borg@adobe.com> > > > Cc: Christopher Cameron <ccameron@google.com>, Chris Lilley < > chris@w3.org>, "public-colorweb@w3.org" <public-colorweb@w3.org> > > > Subject: Re: HTML Canvas - Transforms for HDR and WCG > > > > > > Hi Lars, > > > > > > I think the group will need details before the group can take any > > > meaningful action: > > > > > > - file format(s) used > > > - codec(s) used > > > - colorimetry metadata within the codec (if any) > > > - colorimetry metadata within the file (if any) > > > - colorimetry metadata within the ICC profile > > > - etc. > > > > > > Best, > > > > > > -- Pierre > > > > > > On Mon, May 3, 2021 at 12:13 AM Lars Borg <borg@adobe.com> wrote: > > > > > > > > The images with hlg and pq encoding and icc profiles already exist. > Started several years ago afaik. If you need to know I can find out when we > shipped our first such profile. > > > > Doing an hdr canvas with these images would be new. > > > > > > > > Thanks, > > > > > > > > Lars Borg > > > > Adobe > > > > Hawaii > > > > > > > > ________________________________ > > > > From: Pierre-Anthony Lemieux <pal@sandflow.com> > > > > Sent: Sunday, May 2, 2021 2:29:04 PM > > > > To: Lars Borg <borg@adobe.com> > > > > Cc: Christopher Cameron <ccameron@google.com>; Chris Lilley < > chris@w3.org>; public-colorweb@w3.org <public-colorweb@w3.org> > > > > Subject: Re: HTML Canvas - Transforms for HDR and WCG > > > > > > > > > Legacy. > > > > > > > > I do not see legacy playing a role here since HDR is new to the web.. > > > > > > > > On Sun, May 2, 2021 at 5:03 PM Lars Borg <borg@adobe.com> wrote: > > > > > > > > > > Legacy. > > > > > > > > > > Lars > > > > > > > > > > -----Original Message----- > > > > > From: Pierre Lemieux <pal@sandflow.com> > > > > > Date: Saturday, May 1, 2021 at 2:26 PM > > > > > To: Christopher Cameron <ccameron@google.com> > > > > > Cc: Chris Lilley <chris@w3.org>, "public-colorweb@w3.org" < > public-colorweb@w3.org> > > > > > Subject: Re: HTML Canvas - Transforms for HDR and WCG > > > > > Resent-From: <public-colorweb@w3.org> > > > > > Resent-Date: Saturday, May 1, 2021 at 2:26 PM > > > > > > > > > > > To the original question of "what to do about ICC profiles > specifying HLG anonymously?". > > > > > > > > > > What is the use case for not specifying the pixel color scheme? > > > > > > > > > > Best, > > > > > > > > > > -- Pierre > > > > > > > > > > On Sat, May 1, 2021 at 5:19 PM Christopher Cameron < > ccameron@google.com> wrote: > > > > > > > > > > > > On Thu, Apr 29, 2021 at 10:34 AM Chris Lilley <chris@w3.org> > wrote: > > > > > >> > > > > > >> > > > > > >> On 2021-04-28 15:23, Christopher Cameron wrote: > > > > > >> > In all browsers today, for "Colorbars in HLG 203 > display.png", any > > > > > >> > signal value above 0.75 is clamped to SDR-white. > > > > > >> > > > > > >> The choice of 0.75 follows from the HLG specification - a code > value of > > > > > >> 0.75 is media white, while a code value of 1.0 is peak white > and is 12x > > > > > >> higher luminance. > > > > > >> > > > > > >> The choice of clamping all HDR highlights, with no tone mapping > is an > > > > > >> easy but bad one. However, dislaying HDR content on SDR is in > general > > > > > >> hard; HLG is easier here than PQ (by design). > > > > > > > > > > > > > > > > > > Suppose we have a video that identifies itself as HLG (not > anonymously), and is displayed using a <video> tag on an SDR device. > Should it clamp values above 0.75? My answer is "no". > > > > > > > > > > > > We have established that it is inevitable that pixel values over > 0.75 in an image with the ICC profile "Colorbars in HLG 203 display" will > be clamped. > > > > > > > > > > > > To the original question of "what to do about ICC profiles > specifying HLG anonymously?". My answer would be "treat them as extended > SDR, not as HLG, and there is no way for them to truly be the same as HLG". > > > > > > > > > > > > > > > > > > > > >
Received on Monday, 10 May 2021 19:13:48 UTC