Power Platform Community Forum Thread Details

Generate Thumbnail for large files

Hi Team,

I have developed a custom coding power page, where i have used Dropzone using JS libraries. Where i am uploading multiple files which are .jpeg/.png/.avi/.psd/.psb/.tiff at a time and able to submit to sharepoint library using Chunk model.

I am generating thumbnails using Graph api at runtime once the files are uploaded to sharepoint successfully. The issue i am facing is, i can't generate the thumbnails which are greater than 250MB. Why because Graph cant generate thumbnails >250MB files.

Can anyone suggest me a way to generate thumbnails for large files(1GB/3GB .psd/.psb)?

I know using power automate we can generate thumbnails by using connector computer vision api connector, action Generate Thumbnail.
But, due to DLP restrictions i can't use it in PowerAutomate. I will try to check to check with admin team on that and verify.

Thanks in Advance.

Categories:

Customize & extend

@CU24071054-0

You're correct that Microsoft Graph API has a 250MB limit for generating thumbnails, which poses a challenge for large files like high-resolution PSD/PSB formats. Since Power Automate is restricted due to DLP policies, here are some alternative approaches you can consider:

Alternative Solutions for Generating Thumbnails for Large Files

1. Use a Local or Server-Side Image Processing Tool

You can set up a backend service (e.g., using Node.js, Python, or .NET) that:

Downloads the large file from SharePoint.
Uses a library like:
- ImageMagick or GraphicsMagick (for PSD/PSB support)
- Python PIL/Pillow (for basic image formats)
- PSD.js (for parsing PSD files in Node.js)
Generates a thumbnail (e.g., 300x300px JPEG).
Uploads the thumbnail back to SharePoint or stores it in a separate location.

This avoids the Graph API limitation entirely.

2. Use Desktop Batch Tools like ImBatch

ImBatch is a free Windows tool that can batch process large image files, including resizing and thumbnail generation. You could:

Download the files locally.
Use ImBatch to generate thumbnails.
Re-upload the thumbnails to SharePoint.

This is more manual but useful for one-off or periodic processing.

3. Use Azure Functions or Azure VM

If you're open to cloud solutions outside Power Automate:

Deploy an Azure Function or Azure VM with ImageMagick or another image processing tool.
Trigger it via an HTTP request or SharePoint webhook when a file is uploaded.
Process the file and store the thumbnail.

This gives you full control and avoids DLP issues tied to Power Automate.

🏷️ Tag me if you have any further questions or if the issue persists.

✅ Click "Accept as Solution" if my post helped resolve your issue—it helps others facing similar problems. ❤️ Give it a Like if you found the approach useful in any way.

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