`sig
val image_surface_create_from_channel :
Stdlib.in_channel -> Cairo.image_surface
val image_surface_create_from_file : string -> Cairo.image_surface
external image_surface_create_from_stream :
(string -> unit) -> Cairo.image_surface
= "ml_cairo_image_surface_create_from_png_stream"
val surface_write_to_channel :
[> `Any ] Cairo.surface -> Stdlib.out_channel -> unit
val surface_write_to_file : [> `Any ] Cairo.surface -> string -> unit
external surface_write_to_stream :
[> `Any ] Cairo.surface -> (string -> unit) -> unit
= "ml_cairo_surface_write_to_png_stream"
end`