The following packages contain pixbuf: 
gdk-pixbuf-loaders
gstreamer-gdkpixbuf
lib64gdk-pixbuf-gnomecanvas1
lib64gdk-pixbuf-xlib2
lib64gdk-pixbuf2
lib64gdk-pixbuf2-devel
lib64gdk_pixbuf2.0_0
lib64gdk_pixbuf2.0_0-devel
ruby-gdkpixbuf2