Preview images in modern experience libraries

Question

I am looking at the Modern experience in documents and lists, and specifically the tiles view option.

I can see that the tile preview img tag src attribute for each of the tiles points to the following url:

<img class="od-ImageTile-image" src="https://australiasoutheast1-mediap.svc.ms/transform/thumbnail?provider=spo&inputFormat=png&cs=fFNQTw&docid=https%3A%2F%2Fmytenant.sharepoint.com%3A443%2F_api%2Fv2.0%2Fdrives%2Fb!QTd0bWaqp0m9xt6dA0TZpPKwJE7AaWJPnQIO7sEpJGXSgX2dXgwXR4orEx4jtBgl%2Fitems%2F013366R3CR7MYYFKOSE5EZRQFVHK452X7P%3Fversion%3DPublished&access_token=...&encodeFailures=1&width=172&height=172&srcWidth=&srcHeight=&cropMode=dochead" style="left: 0%; top: 0%; width: 100%;">

Does anyone know if it is possible to call this “service” https://australiasoutheast1-mediap.svc.ms/transform/thumbnail from your own code?

I would love to be able to use this service to generate previews of content in a similar way that the OOTB “tiles” view is doing.

Is there any documentation or other guidance around this?

Thanks in advance

Answer 1

You can make use of the built-in getpreview.ashx handler to generate thumbnails for your document as well as images.

So, for example, if you have uploaded an image in the Images library named test.jpg, then your file path would be something like:

https://tenant.sharepoint.com/sites/test/Images/test.jpg

To get the image preview, you can use the below url:

https://tenant.sharepoint.com/sites/test/_layouts/15/getpreview.ashx?
path=https://tenant.sharepoint.com/sites/test/Images/test.jpg

The same will work for Office documents as well.

Related reading -

Generate thumbnail of a document stored in SharePoint from its URL

Image Renditions available in Modern Team Sites

Answer 2

The following works for files stored in SharePoint Online document libraries using the Graph API to retrieve the thumbnail URLs:

1. Open the Microsoft Graph Explorer site to check your REST call syntax.

2. Call https://graph.microsoft.com/v1.0/sites/contoso.sharepoint.com:/sites/anothersitecollection:/drives to get the document libraries as drives and save the ID of the document library you need. Substitute your SharePoint tenant for "contoso" and your site collection URL component for "anothersitecollection".

3. Call https://graph.microsoft.com/v1.0/drives/b!aXYZmss8ZEiVokyC-JytN274MKTABCdAqaqixLW2-0JqtL9COCftQr9Ct9neeDKJ/root/children to get the documents in the document library. Substitute your long drive ID for the example.

4. Call https://graph.microsoft.com/v1.0/drives/b!aXYZmss8ZEiVokyC-JytN274MKTABCdAqaqixLW2-0JqtL9COCftQr9Ct9neeDKJ/items/01EQBDECC66F3P3O5YI5ABCIGG7O6M4Q23/thumbnails to get the thumbnail URLs. Substitute your long document ID for the example.

From my blog post: http://blog.larslynch.com/2019/01/3d-and-other-thumbnails-in-sharepoint.html