C#/ASP.NET - Get thumbnail from PDF/DOC files

Question

I have an ASP.NET WebForms application (written in C#) that allows users to upload files using the FileUpload control.

What'd be great is if I could automatically generate thumbnails from files. Images such as JPG/PNG are trivial of course, but users will often upload .DOC and .PDF files - is there a way I can essentially convert .DOC and .PDF files to images so I can get a thumbnail?

Thanks!

Answer 1

You can use GhostScriptWrapper for generating image thumbnails directly from pdf.You can get ghostScriptWrapper from GitHub or you can include ghostscript.dll from nuget package manager solution.

Answer 2

On paper the most hopeful approach would be to do so server side. So, if the file were uploaded, the server could generate a preview image.

On Windows, there would be a few options.

a) Windows Shell has a way to do it. The path is dangerous though. b) https://filepreviews.io/ Is a service that does it, but they charge. c) box is another service that does it.

Now on Linux, or even, perhaps, a Linux in a Windows subsystem, could do it with some command line utilities.

a) Convert the doc to pdf:

Convert DOC to PDF

b) Then, get a bitmap of the first page of the pdf, use ghostscript. ghostscript also exists for .NET and Windows.

Bitmap of PDF First Page