301398 2025-10-23 21:18:58 -0700 [HDR] IMG tag CSS features position and transform switch HDR JPEG with gainmap to SDR 2025-11-17 15:09:38 -0800 1 1 1 Unclassified WebKit Images Safari Technology Preview Mac (Apple Silicon) macOS 26 RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=282299 InRadar P2 Normal --- 1 web simon.fraser heycam sabouhallawa simon.fraser webkit-bug-importer oldest_to_newest 2153917 0 web 2025-10-23 21:18:58 -0700 In current release Safari 26.0.1 of macOS 26 and also current Safari Technology Preview 230 on macOS 26, HDR gainmap JPGs are not shown in HDR and switch back to SDR when the img tag attributes position or transform are used. Chrome and Opera do show HDR with these attributes. Example with failed HDR using attributes transform and position: https://areo.info/mars20/ecams/1662/tn/NLF_1662_0814484811_380ECM_N0791762NCAM00501_01_295J_calib01_areo.info.jpg.html Example with working HDR without those attributes: https://areo.info/mars20/ecams/1662/ 2154051 1 webkit-bug-importer 2025-10-24 09:41:40 -0700 <rdar://problem/163347703> 2154174 2 simon.fraser 2025-10-24 16:12:58 -0700 This reproduces in a very simple test case with a relatively-positioned image. The detection code must be failing to traverse into the RenderLayer. 2154195 3 simon.fraser 2025-10-24 20:31:10 -0700 <rdar://156858374> 2154197 4 simon.fraser 2025-10-24 20:39:04 -0700 Pull request: https://github.com/WebKit/WebKit/pull/52982 2154530 5 ews-feeder 2025-10-27 14:51:30 -0700 Committed 302200@main (52936d4f17f0): <https://commits.webkit.org/302200@main> Reviewed commits have been landed. Closing PR #52982 and removing active labels. 2154538 6 web 2025-10-27 14:59:53 -0700 Thanks! I'll try with the next safari tech preview release. 2159383 7 web 2025-11-17 15:09:38 -0800 With Safari Tech Preview 232 (WebKit 21624.1.2.19.2) the large images with those CSS features now display in HDR, thanks!