save xmp to file or convert it to jpeg, png or gif

["Sergey V. Beloshitsky" <snowman ukrpost com ua>]

Hi, all i'm new here an already have a question :)

        i have GdkPixmap *pixmap with a pixmap in it. 
        And i want to convert it to jpeg or png or gif, or just save it to 
file, so How can i do it using gtk or maybe some other stuff 

Please help me enyone