Universal Viewer files blurry


Can someone please help me understand how I can get the zoom in Universal Viewer to display the images with greater clarity? It is completely blurry when the user zooms in. The only option for clarity is to download. Please advise.


If your original images are small, you can’t get them clean. If they are big (more than 1MB to 5MB, according to your server and your user bandwith), you have to create tiles from your images with the plugin OpenLayersZoom (https://omeka.org/add-ons/plugins/openlayerszoom/).

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Ok, thank you. Are there a limited number of tiles that can be selected for zoom? When I have a large number of tiles selected it doesn’t finish the update in a timely way. Also, when I go back to the tiles after they have been selected and updated, the check is gone. Please advise.

You can select the image you want in the user interface. Nevertheless, for big pictures or many pictures, the time to create tiles is too long for a web call (more than 30 seconds). So, if needed, you can run the command line tool “bulk_build_tiles.php”, that is available at the root of plugin. Simply edit it to set the number of the items or items set, and launch it. See readme.

I am not clear how to edit the script to make it work the way I want it to. There is some direction in the command line tool:
You should edit manually the collection id, the item ids or set “$all” to* true. In all cases, processed files are not retiled.
If I understand correctly, it could work for me to set $all to true. I would just appreciate some direction on where specifically to do that. I don’t know the code but can usually work out where to place it with some direction.

You choose what you want. If you want to tile all your files, set $all = true;. If only some collections, set $collection_ids = array(1, 5, 7);. If you want only some items, for example to try, set $item_ids = array(19, 45, 89); (ids are example of course).

Thank you, Daniel, that is very helpful. Is there anything I need to do to run the script or is changing the code sufficient?

No, you don’t need anything else than specify the items you want to tile. Next, go to the root of the plugin.

cd /path/to/my/omeka/plugins/OpenLayersZoom
php -f bulk_build_tiles.php

The process wasn’t quite as simple as anticipated and although it seems to have resolved saving the zoomed files, it still hasn’t resolved the issue of timing out. Any suggestions on how this can be handled? Also, does the command need to be run repeatedly as I add new content? Thanks.

On most servers, the time out is generally 30 seconds for a command run via the web interface (that’s why there may be an issue with OpenLayersZoom with big or numerous files). The time out is unlimited via the command line, so this is the recommanded way to use the plugin. There may be issues on any cms you use, because the configs of the server are various and the cms can’t manage all the cases. I upgraded the plugin In Omeka S and the process is simpler, because it is possible to do such a job as a backgroup process more easily, even in the web interface.

For now, in your Omeka Classic, it seems that there is an issue on your background job configuration. In your config.ini, did you changed the options jobs.dispatcher.default and jobs.dispatcher.longRunning? Did you already use a plugin with a background process?

For the last point, the script can be launched on the command line when you want, even on the same set of items: if the item is already tiled (if there are files in your files/zoom_tiles for this item), it will be skipped.

I did not change the jobs.dispatcher.default and jobs.dispatcher.longRunning in config.ini. I see it there, but am not clear how to change it. Thank you.

So don’t change anything, the job processing will be useless here. I don’t know what is your issue. I didn’t add an web interface to launch the tiling process, but from the command line, nobody tells me about a problem. The script was written by a librarian in Bordeaux and it works fine in all the projects I know. Did you succeed to run it?

My issue is with multiple larger files. The zoom tiling is working fine with single or a few items. I had some help from our hosted web service in running the command line.

Perfect. If the hosting services don’t like when their servers overload, you can do it on your computer and copy the folder of tiles in the good place.

I am at a loss again. My high-resolution files are displaying blurry again in the Universal Viewer. There is no advantage to zooming the tiles because the image is blurry in the Viewer. The thumbnails are fine. Any idea what the problem may be?

Is there a public page to check it?

Here is an example of a recently added file that is blurry in the Viewer:


In this page, the tiles are well created (you can see the manifest here), but they are not available on the server, probably related to the Archive Repertory configuration. In the config of ArchiveRepertory, check if the param “Other derivative folders” contains zoom_tiles|_zdata and that you have read the warning.

There is another issue. In fact, there is a bad redirection:
the iiif link “http://vwudigitalcollections.org/image/4706/full/5958%2C4746/0/default.jpg” redirects to “http://vwudigitalcollections.orghttp//vwudigitalcollections.org/files/zoom_tiles/9/600/twpa-arc-loc-his-pho-026_zdata/TileGroup0/1-1-0.jpg”, and “http://vwudigitalcollections.orghttp//vwudigitalcollections.org” doesn’t exist. So you have to check why.

The tiles are good: http://vwudigitalcollections.org/files/zoom_tiles/9/600/twpa-arc-loc-his-pho-026_zdata/TileGroup0/1-1-0.jpg is available. The issue is just the redirect.

Thank you, Daniel, for providing some direction. I think I’ve resolved the issue. I deactivated the Archive Repertory for now and re-uploaded the files. They seem to be good now and the zoom is working fine too.