230855 2021-09-27 13:21:35 -0700 Canvas memory limit of 4096 × 4096 pixels when calling ctx.getImageData 2025-05-05 07:12:21 -0700 1 1 1 Unclassified WebKit Canvas Safari Technology Preview Unspecified macOS 11 NEW https://bugs.webkit.org/show_bug.cgi?id=230887 https://bugs.webkit.org/show_bug.cgi?id=144335 InRadar P2 Normal --- 1 bramus webkit-unassigned daniel dino ik jarek kevin_neal lwarlow mmaxfield sabouhallawa simon.fraser thorton vepomoc webkit-bug-importer oldest_to_newest 1797613 0 bramus 2021-09-27 13:21:35 -0700 Spotted on Twitter [1], by Rik Schennink “Safari 15 has a canvas memory limit of 4096 × 4096 pixels where Safari 14 could deal with resolutions up to 16384 x 16384” Can verify via the CodePen Demo [2] Rik also shared, in which he creates a 4097x4097 canvas. Upon calling `ctx.getImageData(0, 0, size, size)` the code fails. “Unable to get image data from canvas. Requested size was 4097 x 4097” While searching for bugs I did find [3] where the limit was added for iOS, but this is now applied on macOS too apparently. Is this a regression? [1] https://twitter.com/rikschennink/status/1442443774748082185 [2] https://codepen.io/rikschennink/pen/YzQRdwZ [3] https://bugs.webkit.org/show_bug.cgi?id=145998 1797614 1 bramus 2021-09-27 13:23:15 -0700 I read in https://bugs.webkit.org/show_bug.cgi?id=229237 that the “2D memory limit” test got marked as expected to Crash, so I guess that that explains why this went undetected? 1797797 2 bramus 2021-09-28 02:40:03 -0700 Update: Creating a canvas of 16384 x 16384 on macOS and drawing on it still works. It's only when calling `ctx.getImageData` that Safari fails to cooperate. 1798337 3 kevin_neal 2021-09-29 08:22:24 -0700 Thank you for filing. The appropriate engineers have been notified. 1798338 4 webkit-bug-importer 2021-09-29 08:22:34 -0700 <rdar://problem/83671710> 1803558 5 mmaxfield 2021-10-12 16:45:33 -0700 <rdar://problem/83575501> 1803559 6 mmaxfield 2021-10-12 16:46:34 -0700 static const float MaxClampedLength = 4096; static const float MaxClampedArea = MaxClampedLength * MaxClampedLength; 1803562 7 mmaxfield 2021-10-12 16:47:39 -0700 Might have been caused by https://bugs.webkit.org/show_bug.cgi?id=144335? 1803566 8 simon.fraser 2021-10-12 16:54:33 -0700 Or by the GPU Process?