using a png with alpha channel will be the best suggestion. but maybe you can import a png and use one of cairo painting operator to remove the color.. maybe, i dont know, is just and idea. http://cairographics.org/operators/ i think 1.10 has much more operators than that<div> </div>Jerónimo Barraco Mármol</div> <div>http://nande.com.ar http://ar.linkedin.com/in/nande <div style="font-family: verdana, helvetica, sans-serif; font-size: 12pt;"><div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"><hr size="1">De: Maarten Bosmans <mkbosmans@gmail.com> Para: Carlo <defrag1986@gmail.com> CC: cairo@cairographics.org Enviado: jueves, 27 de octubre de 2011 3:45 Asunto: Re: [cairo] How to use a specified color as png transparent color? 2011/10/26 Carlo <<a ymailto="mailto:defrag1986@gmail.com" href="mailto:defrag1986@gmail.com">defrag1986@gmail.com</a>>: > Hi. I would import a png and copy it on a surface with the "target color" > used as transparent color. > I'm working with different set of png, each set has a background color that > I don't want to show. > How can I make this?? Adding a general remark to Bill's answer: Cairo has no functions for import and export of images. The png related functions are mainly for debugging purposes and intentionally only handle a specific subset of PNG files. Furthermore, Cairo is a vector graphics library, so doing pixel-per-pixel operations on an image is not something we really have good support for. These two thing together mean that you are probably better of using another program/library to edit the png files before you use them in Cairo. Maarten -- cairo mailing list <a ymailto="mailto:cairo@cairographics.org" href="mailto:cairo@cairographics.org">cairo@cairographics.org</a> <a href="http://lists.cairographics.org/mailman/listinfo/cairo" target=_blank >http://lists.cairographics.org/mailman/listinfo/cairo</a> </div></div>