http://www.quickpdf.org/forum/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Sat, 04 Apr 2026 05:51:19 +0000 Thu, 19 Feb 2009 01:52:29 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 11.01 360 www.quickpdf.org/forum/RSS_post_feed.asp?TID=1013 http://www.quickpdf.org/forum/forum_images/QPDF_Forum_Title.png http://www.quickpdf.org/forum/ http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4761.html#4761 Author: Autodidact
Subject: 1013
Posted: 19 Feb 09 at 1:52AM

You can set a mask based on colors in the image as well with SetImageMask/SetImageMaskCMYK, but then it is important that this color is not present in the part of the image that is to be preserved as it will make odd looking holes/gaps. In RGB, using pixels of 100% green should be the safest color to use. Using white would be asking for trouble, and as I see it, there are no way to specify a transparent pixel/color ...

There is also SetClippingPath. Images can have a clipping path added in Photoshop. I assume that would be a bit much to ask from the user to create such a path, and I am not so sure this path is what the documentation refer to but rather a path created with the library. I assume so because the function have no argument to specify the path to use. It only uses the "current path" object.

I guess this is a library limitation, where the creators maybe have chosen the easy route because the library has no support for EPS-vector graphics either, and I could really use that as EMF import is unstable, and neither it or WMF supports CMYK-colors.
]]> Thu, 19 Feb 2009 01:52:29 +0000 http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4761.html#4761 http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4760.html#4760 Author: Eddy
Subject: 1013
Posted: 18 Feb 09 at 5:07PM

 In fact, I'm working on an application in whitch a user can create a pdf file and add images or text in it. So, I can't use the mask, since I don't know in advance whitch kind of image the user will add...
I thought that quickpdf should manage that, may be I'm wrong... or maybe it is a pdf limitation...
Thanks for your answer, even if it is not exactly what I was looking for...

Eddy
]]> Wed, 18 Feb 2009 17:07:36 +0000 http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4760.html#4760 http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4759.html#4759 Author: Autodidact
Subject: 1013
Posted: 18 Feb 09 at 2:05PM

I have only tried placing PNG-files with transparency, and although the file format supports it, the result was just as you experience with the GIF-file.

Since there are functions for making masks in the library, I tend to belive that transparence within the file is not supported. Check out the SetImageAsMask and SetImageMaskFromImage — and perhaps the ReverseImage.

Maybe I should look into it myself too ... 8o)
]]> Wed, 18 Feb 2009 14:05:42 +0000 http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4759.html#4759 http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4758.html#4758 Author: Eddy
Subject: 1013
Posted: 18 Feb 09 at 12:57PM

Hi,
I am trying to add a gif image to a pdf file.
Perhaps my question is stupid, but is it possible to manage the transparency of that image if it is a gif file with transparency ?
I perform a AddImageFromFile, before a drawImage... and the result is an image with a white opaque backstyle... Do I do something wrong ?
Thanks in advance.
Eddy


Edited by Eddy - 18 Feb 09 at 12:58PM]]> Wed, 18 Feb 2009 12:57:15 +0000 http://www.quickpdf.org/forum/adding-a-gif-image-with-transparency_topic1013_post4758.html#4758