Rendering pages to images

Render pages to PNG bytes via PDFtoImage (PDFium):

using var doc = PdfFile.Open("report.pdf");
byte[] png = doc.RenderPage(0, dpi: 150);
File.WriteAllBytes("page1.png", png);

var allPages = doc.RenderAllPages(dpi: 96);

• Page indexes are 0-based.
• dpi controls output resolution; 96 is screen resolution, 150–300 suits print previews and thumbnails at higher fidelity.
• Rendering is also handy for visual testing of fluent layouts together with DebugOverlay().