how to convert the pdf to image by using asp.net

You can use Spire.PDF to convert PDF to TIFF in C#.

 

https://www.e-iceblue.com/Tutorials/Spire.PDF/Spire.PDF-Program-Guide/Conversion/Save-PDF-Document-as-tiff-image.html 

You can use LEADTOOLS Document SDK technology in your application.

https://www.leadtools.com/sdk/products/document

You can leverage the DocumentConverter class, to convert any LEADTOOLS supported file format to any other LEADTOOLS supported file format (i.e. PDF to TIFF). Another option you can look into using is the LEADTOOLS `RasterCodecs` class, which will allow you to convert PDF to an image file like the `DocumentConverter`. The difference is that the `DocumentConverter` class uses a combination of the LEADTOOLS Raster, SVG, OCR, and Document Writers technologies to convert images and documents using the best possible blend of accuracy and speed.

 

For sample code you can take a look at the tutorial in the below link:

https://www.leadtools.com/help/sdk/v21/tutorials/dotnet-console-convert-files-with-the-document-converter.html

 

DISCLOSURE: I am an employee of the company offering this toolkit.

you can try to use PDFLib, it's an open source library, can convert pdf to images. before your coding. how to convert the pdf to image by using asp.net (https://www.iditect.com/tutorial/pdf-to-image/) to have a test.