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empira / PDFsharp-1.5

A .NET library for processing PDF
MIT License
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Converting a pdf to tiff or multiple images? #145

Closed justinmchase closed 1 year ago

justinmchase commented 3 years ago

Suppose I load a PDF using PDFsharp, how can I then render the entire document as a Tiff, or alternately render each page as an image and save to disk?

If I had each page as an image I could figure out how to build a tiff from those images, but I'm struggling to see how to use the XGraphics api to render a page to an image. All the examples I've seen so far do the reverse of rendering an image into the page.

Any help would be greatly appreciated, thanks.

TH-Soft commented 3 years ago

See FAQ No. 3: http://pdfsharp.net/wiki/PDFsharpFAQ.ashx#Can_PDFsharp_show_PDF_files_Print_PDF_files_Create_images_from_PDF_files_3

It'll take some effort on your side to render PDF using the XGraphics class. But this would be an interesting extension.

justinmchase commented 3 years ago

Ok so I see this sample: http://pdfsharp.net/wiki/Preview-sample.ashx

But it's not clear to me how it's being previewed based on that sample code. The sample seems incomplete, the creation of the XGraphics instance is not included for example, and I can't seem to find a full version in the code base.

It says in the code in the example:

"• draw in a bitmap image"

This is what I want I think, but how can I do this? I don't see the API that would allow it.

TH-Soft commented 3 years ago

The complete source code can be found on - surprise, surprise - GitHub: https://github.com/empira/PDFsharp-samples/tree/master/samples/gdi/GraphicsPreview

XGraphics can draw on PDF pages and on any DC, including DCs for printers and bitmaps.

You see a red X on the preview window because PDFs are not rendered there. The PDF shows in the Adobe Reader screen shot.