Display errors on tile borders

[stefanheinze]

In our project we are using OpenSeadragon (4.1.0) to display medical images of big file size by using DZI tiled images in PNG format.

For all of our images we are facing the issue that the tiles are not correctly displayed in some zoom levels.

You can see in the following that in the initial zoom level for this example the blood vessel in the eye looks very thin in that area:

But after zooming in you can see that the vessel has a regular size in that area.

You can find that example for checking also under the following domain.

https://stefanheinze.github.io/openseadragon-tiled-images-bug/

And the source code can be found here: https://github.com/stefanheinze/openseadragon-tiled-images-bug

We checked the tiles and it turns out that there is a tile border at this position. Unfortunately there seems to be an overlap of the tiles which results in the loss of displayed information. This might be acceptable for displaying ordinary photos, but its not acceptable in medical context.

We also checked the tiles itself. They are cutted correctly.

Is this a known problem or are we doing anything wrong in using OpenSeadragon? Are there any solutions for that?

[pearcetm]

Can you try out the current master branch? The new webgl drawer (#2310) should fix tiling artifacts like what you're seeing here.

[iangilman]

@stefanheinze You're likely encountering #1722. The fix for 4.1.0 is to create your images with tile overlap. A more robust fix is on the master branch as @pearcetm says.

[stefanheinze]

Thanks a lot for the fast response. My first test looks very good!

we will do some more tests around it. Very intersting for us is your timeline for the version 5.0.0, is that planned in the near future?

[iangilman]

The timing for 5.0.0 was just being discussed over here: #2482 😊