Blurred image with rotation

[Harmony222]

Hello! We have an image with an overlay, both image and overlay are added as tiled images and the overlay is added with a set opacity. If the viewer is at 0 degrees rotation on page load and then the images are rotated, the overlay image’s edges are blurry. We have imageSmoothingEnabled set to false. The blurred edge resolves upon page reload or viewer resize. If the images are already rotated at page load, the blurred edge is not observed and rotating the image does not result in a blurred edge. I’ve linked 2 videos, the first starts at 0 degree rotation and you can see the overlay edge become blurred upon rotation (the overlay is the orange color). The seconds starts with the images not at 0 degree rotation and demos no blurriness with rotation.
I'm not sure if this is a bug and would appreciate input. Thanks!

Screen.Recording.2024-04-05.at.12.47.42.PM.mov

Screen.Recording.2024-04-05.at.12.47.01.PM.mov

[iangilman]

That's wild! When you say "overlay", what sort of overlay is it? Is it another tiled image that's loaded like the base image? Or is it one of the built-in OSD overlays? Or is it one of the overlay plugins?

Would it be possible to share a repro of this so we can look at the code?

[pearcetm]

What version of OpenSeadragon is are you seeing this behavior with? And, if it is the current build, which drawer are you using (canvas vs webgl)?

My best guess so far is this is related to the sketch canvas some how.

[Harmony222]

That's wild! When you say "overlay", what sort of overlay is it? Is it another tiled image that's loaded like the base image? Or is it one of the built-in OSD overlays? Or is it one of the overlay plugins?

Would it be possible to share a repro of this so we can look at the code?

Our overlays are just another tiled image loaded like the base image (i.e. we are not using built in overlays or plugins). Unfortunately I can't share code : (
The overlay images are loaded the same way our base images are (but with opacity < 1). Interestingly, when I addTiledImage for the overlay withOUT the opacity, the issue does not occur - so seems to be related to using opacity option?

What version of OpenSeadragon is are you seeing this behavior with? And, if it is the current build, which drawer are you using (canvas vs webgl)?

My best guess so far is this is related to the sketch canvas some how.

We are using v4.1.0 and are using canvas drawer.

[pearcetm]

I'd be curious if the problem would be solved if you built from master and used drawer: webgl instead of canvas

[Harmony222]

I'd be curious if the problem would be solved if you built from master and used drawer: webgl instead of canvas

Thanks for the suggestion. My initial attempt at building from master and using drawer: webgl is creating smooth/blurred edges all around, but there may be some additional changes I need to make in our application to get this working correctly. I see that imageSmoothingEnabled only applies when using the canvas drawer, is it expected that the webgl drawer will always draw smooth edges? or is there a separate setting for this that I am not seeing?

[pearcetm]

The “imageSmoothingEnabled” setting relates to how pixels are rendered by canvas implementations when zoomed. It doesn’t really relate to edges, and the webgl rendering pipeline automatically handles this and isn’t affected by the setting. It should always draw smooth edges (and avoid tiling artifacts too).

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On Tue, Apr 9, 2024 at 8:18 PM Harmony Scarlet ***@***.***> wrote: I'd be curious if the problem would be solved if you built from master and used drawer: webgl instead of canvas Thanks for the suggestion. My initial attempt at building from master and using drawer: webgl is creating smooth/blurred edges all around, but there may be some additional changes I need to make in our application to get this working correctly. I see that imageSmoothingEnabled only applies when using the canvas drawer, is it expected that the webgl drawer will always draw smooth edges? or is there a separate setting for this that I am not seeing? — Reply to this email directly, view it on GitHub <#2508 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AC7LYHPJ54KOKKKUFFNUB4LY4SAPFAVCNFSM6AAAAABFZWR4NCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDANBWGIZTKNJVHA> . You are receiving this because you commented.Message ID: ***@***.***>