Hi Prasanti,
Thanks for inquiring Aspose.Slides.
I have observed the requirements shared by you and regret to share that what you are looking for is not possible using Aspose.SlAides. Aspose.Slides offers to generate the thumbnails of slides inside presentation. If you are interested in generating the slide thumbnails then please visit this documentation link for your kind reference.
If you have any further technical inquiries related to Aspose.Slides features support and their useability you are always welcome to share with us.
Many Thanks,