Way to determine if page is empty

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tdonovan
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Posts: 61
Joined: Tue Jun 12, 2007 9:21 pm

Way to determine if page is empty

Post by tdonovan »

I can determine if there is any text on a page, but do not know how to determine if there are any images on a page. I would like to be able to determine if the page is just a blank page and doesn't have any text or images. How do I determine if there are images on a page.

Thank you.
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Vasyl - PDF-XChange
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Posts: 2445
Joined: Thu Jun 30, 2005 4:11 pm

Re: Way to determine if page is empty

Post by Vasyl - PDF-XChange »

Hi, tdonovan.

It is too difficult to say that page is blank or not... In common case you must have exact feedback info from pdf-renderer - something was painted or not.
Еven in this case, you are not protected from trouble - page can have a simple white rectangle and the pdf-renderer will say: "the visible content exists and was painted"..

I think you must rasterize the page and when result-image isn't a simple white rectangle - then page isn't blank... Or more correct way - rasterize page with "fully transparent background" option, and when result-image is still fully transparent - then page is actually blank.

HTH.
PDF-XChange Co. LTD (Project Developer)

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tdonovan
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Posts: 61
Joined: Tue Jun 12, 2007 9:21 pm

Re: Way to determine if page is empty

Post by tdonovan »

Maybe someday in the future you could add a feature to allow us to determine this. I understand exactly what you are saying and will work on implementing. Just thinking maybe the viewer could determine this without having to generate the image and examine the image. Thanks.