> On Mar 22, 2016, at 6:54 pm, Rik Cabanier <cabanier@gmail.com> wrote: > > On Tue, Mar 22, 2016 at 5:49 PM, Simon Fraser <smfr@me.com <mailto:smfr@me.com>> wrote: > > > The 4k/5k iMac and the new iPad Pro composite in unclipped sRGB, and map to the display colorspace (DCI-P3) at the end. We (WebKit) have no control over the colorspace used for compositing, so we don’t have knobs to tune here. > > Why can't you use colorsync? > https://developer.apple.com/library/ios/technotes/tn2313/_index.html#//apple_ref/doc/uid/DTS40014694-CH1-FRAMEWORKS_FOR_COLOR_MATCHING_WHEN_RENDERING_TO_THE_DISPLAY <https://developer.apple.com/library/ios/technotes/tn2313/_index.html#//apple_ref/doc/uid/DTS40014694-CH1-FRAMEWORKS_FOR_COLOR_MATCHING_WHEN_RENDERING_TO_THE_DISPLAY> > ColorSync is about doing color matching, not composting. To be clear, when I say “compositing” here I mean what happens when you paint non-opaque images and colors on top of each other, and when the GPU composites non-opaque textures. > Also, if you composite in unclipped sRGB, how are you honoring images with a high gamut profile such as p3 or AdobeRGB? Because it’s unclipped? Compositing happens in 10-bit or half-float textures which may contain < 0 or > 1 values. A P3 image is mapped into this unclipped sRGB space for compositing, then the final result is mapped into Display-P3 at the end. Simon
Received on Wednesday, 23 March 2016 05:20:03 UTC