After watching the (excellent) EDR session at WWDC, I'm trying to understand EDR's ability to take advantage of larger headroom when display brightness is dimmed. I'm testing on a MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports) running Big Sur 11.3 (20E232), using the "Color LCD" profile that shipped with the Mac. I believe this display has a max brightness of 500 nits. At full brightness, maximumExtendedDynamicRangeColorComponentValue returns 1.25. When I turn the display brightness down, maximumExtendedDynamicRangeColorComponentValue increases, up to the maximumPotentialExtendedDynamicRangeColorComponentValue of 2.0. However, it hits this maximum surprisingly quickly, when display brightness is only slightly reduced (kIODisplayBrightnessKey returned 0.9863281). Visually testing an OpenEXR version of the Luxo image (found here http://markfairchild.org/HDRPS/Scenes/LuxoDoubleChecker.html) in Preview.app reveals that, indeed, a few more clipped highlights become unclipped at this slightly-reduced display brightness. Cool! What I don't understand is why I'm capped to 2.0. Where is this cap coming from? Intuitively, I thought maximumExtendedDynamicRangeColorComponentValue would increase with every step down in display brightness, all the way down to the minimum display brightness, but that is evidently not the case, at least on this hardware/OS/display profile/NSScreen instance.

I use AVSimpleBufferDisplayLayer to show HDR videos in my app, the content is displayed well when the HDR video is going on, but the screenshot image of the HDR Video is overexposed. The screenshot is the system behavior, is there anything developers can do to avoid overexposed when screenshot ? NEED HELP.

Hi, Does the bitmapImageRepForCachingDisplayInRect function support EDR environment on an display with XDR capabilities, and in particular the wantsExtendedDynamicRangeContent flag? And in this case, is the created bitmap 16 or 32 bits? With float or integer channels? Is its associated color space a P3 one ?

I'm trying to set a complete pipeline that conforms to the EDR environment. Currently, I am able to generate a half-float buffer that contains my renderings after using my own tone mapping (and of course, with values that can be greater than 1).  Firstly, I have to say that this produces really awesome outputs on the new M1 XDR screen! But now, I would like to keep this extended buffer into an image file... I found no clear answer in the excellent WWDC presentation video (WWDC 2021 10161).  ken Greenebaum talks about creating CGImage or texture from HDR resources, but I found nothing about the reverse operation.  So what are Apple’s recommendations and required formats for such an image with float channels? HEIC? PNG? JPEG 2000? OpenEXR? With what kind of extended range color space? Extended linear display P3? Is the resultant image viewable in HDR in macOS. How can I complement the pipeline? I can use OpenEXR, but I have no clue on how this will be rendered by macOS, the finder and Preview (is 111 reference white? Can I attach a color space to OpenEXR? ...) At the moment, I had no success with the HEIC format which I thought was the predestined format for this kind of task, but which I failed to generate beyond 8 bits by using the standard CGImage API. By advance, thanks  for your help!

Could someone please confirm that NSImageView does not support the EDR environment for HDR contents? All my attempts failed... And as far as I know, there is no way to set maximumExtendedDynamicRangeColorComponentValue on NSImageView. Thanks!

I'm looking to use high-quality and large images as animated sprites via SpriteKit. Is it possible to display sprites with HDR colors in SpriteKit? What about SpriteKit via SceneKit or RealityKit? I've looked all around and it seems as though *.PNG is the only accepted image format, and it doesn't seem to have HDR support.