Programming Camlimages

Core Manual is here. Please refer to for how to programming o'caml with camlimages and other development kits. An example 1.ml to write image to bmp file:

open Graphics;;
open Images;; (*before versioni 2.4, it's Image*)
open Rgb24;;
open_graph "";;
 let sx, sy = size_x (), size_y () in
  let maxr = min (sx / 4) (sy / 4) and maxc = 256 in
  while not (key_pressed ()) do
    let x, y, r, color =
      Random.int sx, Random.int sy, Random.int maxr,
      rgb (Random.int maxc) (Random.int maxc) (Random.int maxc) in
    Graphics.set_color color; fill_circle x y r
  done              ;;
 let img = Graphic_image.image_of (get_image 0 0 (size_x ()) (size_y()));;
Bmp.save "ddd" [] (Images.Rgb24 img);;

Here, the third para of Bmp.save is Images.t; Graphic_image.image_of returns a value with type of Rgb24.t; Images.t is a sum type:

type t=
   | Index8 of Index8.t
   | Rgb24 of Rgb24.t
   | Index16 of Index16.t
   | Rgba32 of Rgba32.t
   | Cmyk32 of Cmyk32.t

thus, (Images.Rgb24 img)'s type is Image.t
To load needed modules, there are several methods.

1. during compile: ocamlc -I /usr/lib/ocaml/camlimages ci_core.cma graphics.cma ci_graphics.cma ci_bmp.cma 1.ml
2. in top-level: start ocaml, and then: #directory "/usr/lib/ocaml/camlimages";; #load "ci_core.cma";; #load "graphics.cma";; #load "ci_graphics.cma";; #load "ci_graphics.cma";; #load "ci_bmp.cma";;
   furthurmore, by adding these commands to 1.ml, it can be interpreted by ocaml directly.