Module Images

The image data structure definition.

exception Out_of_image

Exception for illegal point access

exception Wrong_image_type

Exception for illegal internal image type

exception Wrong_file_type

Exception for unsupported image FILE format

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

Generic image type

type sequence = {
seq_width : int;
seq_height : int;
seq_frames : frame list;
seq_loops : int;
}
and frame = {
frame_left : int;
frame_top : int;
frame_image : t;
frame_delay : int;
}
type rgb = Color.rgb = {
mutable r : int;
mutable g : int;
mutable b : int;
}

Colors: the copies of color.mli

type rgba = Color.rgba = {
color : rgb;
mutable alpha : int;
}
type cmyk = Color.cmyk = {
mutable c : int;
mutable m : int;
mutable y : int;
mutable k : int;
}
type 'a map = 'a Color.map = {
mutable max : int;
mutable map : 'a array;
}
type format =
| Gif
| Bmp
| Jpeg
| Tiff
| Png
| Xpm
| Ppm
| Ps

Image formats

val extension : format -> string

Functions for filename extensions

returns the corresponding extension "gif", "bmp" etc. for given format

val guess_format : string -> format

returns the image format guessed from the file extension of a given file name

val get_extension : string -> string * string

Lower interface

val guess_extension : string -> format
type colormodel = Info.colormodel =
| Gray
| RGB
| Index
| GrayA
| RGBA
| YCbCr
| CMYK
type info = Info.info =
| Info_DPI of float

dot per inch

| Info_BigEndian
| Info_LittleEndian

endianness of image file

| Info_ColorModel of colormodel

color model of image file

| Info_Depth of int

Image bit depth

| Info_Corrupted

For corrupted PNG files

Infos attached to bitmaps

val dpi : info list -> float option

Info query

type header = {
header_width : int;
header_height : int;
header_infos : info list;
}

Image file header

val file_format : string -> format * header

file_format filename reads the header of image file filename and returns its format and some useful information found in the header (ex. width, height). file_format does not read image contents, but just quickly returns file header information.

file_format does not depend on any external libraries

type load_option =
| Load_Progress of float -> unit

For progress meters

| Load_Resolution of float * float

Pixel/Inch for rasterization of PS

| Load_only_the_first_frame

Load only the first frame of an animation

Load options

type save_option =
| Save_Quality of int

Save quality for Jpeg compression

| Save_Progress of float -> unit

For progress meters

| Save_Interlace

Interlaced Gif

Save options

val load_progress : load_option list -> (float -> unit) option

Option queries

val load_resolution : load_option list -> (float * float) option
val save_progress : save_option list -> (float -> unit) option
val save_interlace : save_option list -> bool
val save_quality : save_option list -> int option
type format_methods = {
check_header : string -> header;
load : (string -> load_option list -> t) option;
save : (string -> save_option list -> t -> unit) option;
load_sequence : (string -> load_option list -> sequence) option;
save_sequence : (string -> save_option list -> sequence -> unit) option;
}
val add_methods : format -> format_methods -> unit

If you write new drivers for some image format, use this function to register their loading/saving functions into the libaray

val load : string -> load_option list -> t

load filename options read the header of an image file filename, loads the image by calling corresponding loading method, and returns it. If the file format is not supported by the library, a Wrong_file_type exception will be raised. You can specify loading options in options such as progressive meter function.

val save : string -> format option -> save_option list -> t -> unit

save filename formatopt options image saves image into a file filename. The image format can be specified by formatopt. If formatopt is Some format, then format is used. If it is None, then the image format is guessed from filename. You can specify some saving parameters options. Some options are specific to some image formats and do not work with the others.

val load_sequence : string -> load_option list -> sequence
val save_sequence : string -> format option -> save_option list -> sequence -> unit
val unoptimize_sequence : sequence -> sequence
val size : t -> int * int

Returns size (width and height) of image

val destroy : t -> unit

Free the image. If you turn on image swapping (see bitmap.mli), you can call this function explicitly to tell the library that this image is no longer used. (This is not required, though.)

val sub : t -> int -> int -> int -> int -> t

sub dst x y width height returns sub-bitmap of dst, at (x, y) - (x + width - 1, y + height - 1).

val blit : t -> int -> int -> t -> int -> int -> int -> int -> unit

blit src sx sy dst dx dy width height copies the rectangle region of src at (sx, sy) - (sx + width - 1, sy + height - 1) to dst, at (dx, dy) - (dx + width - 1, dy + height - 1).

val blocks : t -> int * int