Thank you for using syncfusion product.
Yes we can export the images using SfPdfViewer Control. We have created the sample which exports first page of the PDF document as the image by using the following code snippet:
Image page = pdfViewerControl1.GetPage(0);
Also please find the sample from the below link,
In this sample, the first five pages of the document will export as images if we clicked the Exported first page.
Please let us know if you need further assistance.
Thank you for your update,
Using SfRichTextBoxAdv control you can retrieve the pages as bitmap image. For Your reference we have prepared a sample to illustrate your requirement to get first page in SfRichTextBoxAdv control as bitmap image. Please do find the sample from below link.
Yes, In PdfViewer Control we can load only one document at a time. So if one wants to get the first page of the 15 documents they need to load all those documents separately in PdfViewer Control.
Please let us know if you have any other questions.