Using masks for image transparency

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   Hi everyone,
I'm just new to the QuickPDF library and I was wondering if someone had a small example of how to set a mask to preserve the transparency in a GIF or PNG image in the outgoing PDF.
I've checked the bug list and I'm assuming that this works as expected.
Mark

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mrickan Members Profile Find Members Posts Beginner Joined: 22 Jan 06 Location: Canada Status: Offline Points: 2	Post Options Post Reply Quote mrickan Report Post Thanks(0) Quote Reply Topic: Using masks for image transparency Posted: 22 Jan 06 at 11:44PM
	Hi everyone, I'm just new to the QuickPDF library and I was wondering if someone had a small example of how to set a mask to preserve the transparency in a GIF or PNG image in the outgoing PDF. I've checked the bug list and I'm assuming that this works as expected. Mark

Michel_K17 Members Profile Find Members Posts Newbie www.exp-systems.com Joined: 25 Jan 03 Status: Offline Points: 297	Post Options Post Reply Quote Michel_K17 Report Post Thanks(0) Quote Reply Posted: 24 Jan 06 at 10:56PM
	The use of transparencies in PDFs is an interesting subject. Transparencies are indeed supported since specification v1.3 (Acrobat v5) but it is not supported by the Postscript Printer language. Therefore, a transparent object in a program such as MS Word will not look "right" in the PDF, and will usually be a simulated transparency (a bitmap with holes). With respect to the quickpdf library, I have good news and bad news: you can insert transparent GIF files, and they seem to be handled properly and will even display properly in the PDF Reader. However, the bad news, if you also decide to use QuickPDF to display a PDF by generating an image of a page of a PDF will convert the transparent GIF into garbage (all garbled). Therefore, if you plan to use quickPDF to render, then you will hit that limitation. Otherwise, you should be OK.

mrickan Members Profile Find Members Posts Beginner Joined: 22 Jan 06 Location: Canada Status: Offline Points: 2	Post Options Post Reply Quote mrickan Report Post Thanks(0) Quote Reply Posted: 24 Jan 06 at 11:40PM
	This is encouraging from the PDF generation side at least. Have you had any success using the masking features for this purpose? I've been able to set the transparent colour for an image using SetImageMask but it's not clear to me the order of operations to do the same using SetImageMaskfromImage.