Generate PDF page thumbnails in Xamarin.iOS

To create a PDF page thumbnail in multiple image formats.

PDFDoc doc = new PDFDoc(filename);
PDFDraw draw = new PDFDraw();

// set the output resolution
draw.SetDPI(92);

// Rasterize the first page in the document and save the result as PNG.
Page pg = doc.GetPage(1);
draw.Export(pg, output_filename, "PNG");

Convert PDF to image (JPG, PNG, BMP, TIFF)
Full code sample illustrates how to use the built-in rasterizer in order to render PDF images on the fly and how to save resulting images in PNG and JPEG format.

More image format options:

• "RAW" : RAW format.

  There are four possibilities:

  • e_rgba - if transparent and color page;
  • e_gray_alpha - if transparent and gray page;
  • e_rgb - if opaque and color page;
  • e_gray - if opaque and gray page. NOTE that if page is set to be transparent (SetPageTransparent), the output color channels are already multiplied by the alpha channel.

• "BMP" : Bitmap image format (BMP)

• "JPEG" : Joint Photographic Experts Group (JPEG) image format

• "PNG" : 24-bit W3C Portable Network Graphics (PNG) image format

• "PNG8" : 8-bit, palettized PNG format. The exported file size should be smaller than the one generated using "PNG", possibly at the expense of some image quality.

• "TIFF" : Tag Image File Format (TIFF) image format.

• "TIFF8" : Tag Image File Format (TIFF) image format (with 8-bit palete).