a function that is called to save each block of data that the save routine generates. [scope call]
user data to pass to the save function. [closure save_func]
name of file format.
name of options to set, NULL-terminated. [array zero-terminated=1][element-type utf8]
values for named options. [array zero-terminated=1][element-type utf8]
whether an error was set
GException on failure.
Saves pixbuf to a callback in format type, which is currently "jpeg", "png", "tiff", "ico" or "bmp". If error is set, FALSE will be returned. See gdk_pixbuf_save_to_callback() for more details. Since 2.4