General Discussion - Asymmetrical DPI Rendering

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Asymmetrical DPI Rendering

Printed From: Debenu Quick PDF Library - PDF SDK Community Forum
Category: For Users of the Library
Forum Name: General Discussion
Forum Description: Discussion board for Debenu Quick PDF Library and Debenu PDF Viewer SDK
URL: http://www.quickpdf.org/forum/forum_posts.asp?TID=2415
Printed Date: 26 Nov 24 at 8:58AM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com

Topic: Asymmetrical DPI Rendering

Posted By: Eric24
Subject: Asymmetrical DPI Rendering
Date Posted: 23 Sep 12 at 10:18PM

Anything on the horizon for asymmetrical DPI rendering?

Replies:

Posted By: AndrewC
Date Posted: 24 Sep 12 at 8:46AM

I am wondering why you you need asymmetrical DPI rendering for ? Fax images ?

Andrew.

Posted By: tfrost
Date Posted: 29 Sep 12 at 11:58AM

I would be interested in this feature also. For fax images. 204x196 can be approximated with 200x200, but to create a low-resolution 204x98 you can usually get better quality going direct than converting high to low.

Posted By: Eric24
Date Posted: 11 Oct 12 at 2:25PM

Yes, that's correct. It's subtle, but rendering a fax at 200x200 or 200x100 causes just enough distortion to cause problems. I've experimented with things like rendering at very high resolution (i.e. 400x400 or 600x600) and then resizing the resulting image to 204x196. That actually works reasonably well, but the overhead of rendering such a large file makes it unusably slow.

As-is, the RenderPageToFile or RenderDocumentToFile functions are ideal for my purpose, with the one exception of the single DPI parameter. If it had DPIX and DPIY, I'd be golden!

PS - I'm assuming that using the RenderPageToFile function on a multi-page document that's already been loaded into memory doesn't have to "re parse" the entire PDF file for each call to RenderPageToFile?