Bug 288705 – [HDR] Enable SupportHDRDisplay feature by default

• Status: RESOLVED
• Resolution: FIXED
• Component: Images

[Said Abou-Hallawa]

The feature is usable and testable right now.

[Radar WebKit Bug Importer]

<rdar://problem/145723539>

[Radar WebKit Bug Importer]

<rdar://problem/145723657>

[Said Abou-Hallawa]

Pull request: https://github.com/WebKit/WebKit/pull/41501

[EWS]

Committed 291387@main (c8790926c7ec): <https://commits.webkit.org/291387@main>

Reviewed commits have been landed. Closing PR #41501 and removing active labels.

[Greg]

Great to see this coming!

Any more info on how to enable and test this in Safari 215? I see "support HDR display" dev flag enabled and am trying both HDR and gain map formats in AVIF, HEIF, JPG, and JXL but see only SDR results. Running MacOS 15.3.2, is Sequoia beta required here?

[isenberg]

On my 15.3.2 on the Macbook Pro M2 with today's preview 215 from https://developer.apple.com/safari/resources I can see HDR in the HDR image gallery on https://gregbenzphotography.com/hdr which isn't presented in HDR on the normal release Safari. But no all features on the page show up in HDR.

But my HDR JPEGs on https://areo.info/mars20 are only shown in SDR so far there.

[isenberg]

Release 215 (Safari 18.4, WebKit 20622.1.6.111.4
Test #8 a - c: fail
Test #8 d: shows the extreme white text
Test #9, 10, 11 passes

[Greg]

@isenberg My images are not showing as HDR on https://gregbenzphotography.com/hdr, they are using an improved tone mapping. For example, note that the top of #2 (HDR spectrum) that the maximum white in the image matches the page background). Or just compare the page to an HDR capable browser like Chrome on an HDR capable monitor.

Test #8d (the JXL gain map is interesting). The result from production Safari v18.3.1 is correct if the display is SDR (my display is not, but this seems to show some awareness of JXL gain maps and decoding to SDR). The behavior in Safari Tech Preview 215 shows no support for the JXL gain map (expected result would be you do not see the white text on the display when there is 0 HDR headroom). I am not surprised to see the tech preview fail, but I am surprised at how the regular version of Safari seems to manage it (sort of, as the HDR display result is wrong).

Aside from #8d and the tone mapping, the results in the tech preview are same as the production Safari. Unless I am missing some setting to enable, the current tech preview does not successfully display any HDR photos. I have been unable to get any HDR photo (JGP, JXL, AVIF, or HEIF using simple HDR or gain maps) to work.

I do see that Lightroom on the web now shows proper HDR display and editing (this is not an HDR photo, looks like an HDR <canvas> element).

[isenberg]

I compared again with Chrome on my 15.3.2 Macbook Pro M2 and the 10 HDR images in the gallery are identical to Chrome with nice HDR. Also the #2 spectrum shows a brighter white than the page background. Just the JPEG with gainmaps are missing. Maybe you used a slightly older tech preview build 215? Mine is 215 Safari 18.4, WebKit 20622.1.6.111.4.

[Greg]

That's very interesting. It clearly fails in my setup using Safari Tech Preview Release 215 (Safari 18.4, WebKit 20622.1.6.111.4) under MacOS 15.3.2 on an M4 Max MBP. There are dev flags for HDR in the Safari Tech Preview, and they (along with all GPU flags) are enabled in my setup.

I've heard from several others that the tech preview also failed to render photos as HDR, you are the first to report success. Are you using a MacOS beta or any special settings? 

The images on my test page are a mix of formats, but most of the images are simple HDR AVIF (very little use of gain maps on that page as most of the demo images were posted before gain maps were an option and I have yet to update them).

[isenberg]

All standard here, nothing custom or beta and on the built-in screen. The only special setting could be the enabled Developer Menu in Safari where I can see the following which was already enabled in the Feature Flags section:
WebGPU support for HDR: Preview
Support HDR Display: Stable

I'll compare later today with my M1 Macbook Air and the external HDR screen.

[isenberg]

Also works fine with that tech preview in HDR on the Macbook Air M1 on its built-in screen, there of course less HDR headroom, and when attached to the external HDR display.

[isenberg]

Created attachment 474695 [details]
HDR visible in screenshot Macbook Pro M2 gregs testpage 1

[isenberg]

Created attachment 474696 [details]
HDR visible in screenshot Macbook Pro M2 gregs testpage 2

[isenberg]

I've added two photos showing HDR mostly working on a Macbook Pro M2 in 215 Safari 18.4, WebKit 20622.1.6.111.4:
HDR visible in screenshot Macbook Pro M2 gregs testpage 1
HDR visible in screenshot Macbook Pro M2 gregs testpage 2

What's missing is the support for JPEG with gain maps (Adobe and ISO format).

[Greg]

I'm seeing that the CSS media under tech preview 215 query fails when using ProDisplay XDR, but works for 14" M4 Max MBP. There are display-specific failures for HDR either in this build or in MacOS in a way that affects this build. Submitting details in Apple Feedback Assistant.

[isenberg]

On my external non-Apple HDR screen it works fine on both Macbooks, attached over USB-C.
In case other readers are wondering: The screen photos are taken with a Samsung phone as JPEG with gainmap. Works for example in Display.app on Macbooks, otherwise only the SDR part will be shown.

[isenberg]

Correction: Preview.app I meant.