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How to speed up thumbnail generation?

Posted: Thu Jul 13, 2017 3:39 am
by accudave
Hey there,
I am generating thumbnails by using GdPictureImaging.GetThumbnailHQ, but it is pretty slow. This is quite noticeable on larger documents (e.g 30 pages takes over 3-4 seconds). The non-HQ method is not much faster.

Is there a way to use parallel processing? I have attempted this, but it appears that this cannot be done due to the underlying stream being accessed by multiple threads at the same time. Appears GdPicture cannot handle this scenario. I can open a new stream for each page on each core, but that is slower due to having to open the file each time.

Using ThumbnailEx for WinForms or WPF is not really an option at the moment. Are there any techniques that can be applied using just the API you provide? Or am I stuck here?

(This would be for both TIF and PDF, though right now I'm testing on TIF documents)

Re: How to speed up thumbnail generation?

Posted: Thu Mar 14, 2019 5:30 pm
by Hugo
Hi there,

Are you still experiencing these difficulties on the latest version of GdPicture?