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All images handled by this module are stored as 24-bit RGB images. This means that a 1024 pixel wide and 1024 pixel high image will use 1024*1024*3 bytes = 3 megabytes. It is quite easy to mess up and use up all the memory by giving the wrong argument to one of the scaling functions.
Most functions in this module work by creating a new Image and then returning that instead of changing the Image you are working with. This makes it possible to share the same image between many variables without having to worry that it will be changed by accident. This can reduce the amount of memory used.
Many functions in this module work with the 'current color', this can be thought of as the background color if you wish. To change the current color you use 'setcolor'.
Let's look at an example of how this can be used:
This very simple example can be used as a CGI script to produce a gif image which says what time it is in white text on a black background.#!/usr/local/bin/pike
int main()
{
write("Content-type: image/gif\n\n");
object font=Image.font();
font->load("testfont");
object image=font->write(ctime(time));
write(Image.GIF.encode(image));
}
| Image.Image | Basic image manipulation |
| Image.Font | Creating images from text |
| Image.Colortable | Color reduction, quantisation and dither |
| Image.Color | Color names, objects and conversion |
| encoding/decoding image files | |
| Image.GIF | GIF encoding/decoding capabilities |
| Image.JPEG | JPEG encoding/decoding capabilities (needs libjpeg) |
| Image.PNG | PNG encoding/decoding capabilities (needs libz) |
| Image.PNM | PNM (PBM/PGM/PPM) encoding/decoding capabilities |
| Image.XFace | XFace encoding/decoding capabilities (needs libgmp) |
| Image.XWD | XWD (X-windows dump) decoding capabilities |
| advanced | |
| Image.X | module for supporting X-windows low-level formats, keeping a lot of bit-mending stuff. |
Image module documentation is based on these file versions:$Id: blit.c,v 1.37 1999/06/18 19:19:14 mirar Exp $ $Id: blit_layer_include.h,v 1.6 1999/04/13 12:32:11 mirar Exp $ $Id: colors.c,v 1.30 2000/02/03 19:02:22 grubba Exp $ $Id: colortable.c,v 1.77 1999/10/30 11:51:41 mirar Exp $ $Id: colortable.h,v 1.17 1999/04/11 12:55:43 mirar Exp $ $Id: colortable_lookup.h,v 1.9 1999/04/10 02:02:07 mirar Exp $ $Id: dct.c,v 1.14 1999/06/18 19:19:20 mirar Exp $ $Id: any.c,v 1.16 2000/03/22 18:12:19 peter Exp $ $Id: bmp.c,v 1.20 2000/02/03 12:25:18 grubba Exp $ $Id: gif.c,v 1.50 1999/11/14 22:16:08 mast Exp $ $Id: gif_lzw.c,v 1.6 1999/05/30 20:11:14 mirar Exp $ $Id: gif_lzw.h,v 1.7 1999/05/30 20:11:15 mirar Exp $ $Id: ilbm.c,v 1.13 2000/02/03 19:01:29 grubba Exp $ $Id: pnm.c,v 1.20 1999/06/19 11:08:00 mirar Exp $ $Id: x.c,v 1.26 2000/03/27 07:42:35 hubbe Exp $ $Id: xwd.c,v 1.13 2000/01/11 01:42:36 mast Exp $ $Id: font.c,v 1.58 2000/03/25 23:34:32 hubbe Exp $ $Id: image.c,v 1.160 2000/04/09 06:15:17 per Exp $ $Id: image.h,v 1.35 1999/09/25 19:58:48 grubba Exp $ $Id: layers.c,v 1.43 2000/02/22 03:41:27 per Exp $ $Id: matrix.c,v 1.22 2000/04/09 06:15:17 per Exp $ $Id: operator.c,v 1.25 1999/09/14 23:17:15 marcus Exp $ $Id: orient.c,v 1.13 1999/06/19 20:24:48 hubbe Exp $ $Id: pattern.c,v 1.18 1999/07/16 11:44:20 mirar Exp $ $Id: poly.c,v 1.3 1999/07/28 09:26:20 mirar Exp $ $Id: polyfill.c,v 1.30 1999/06/19 20:24:49 hubbe Exp $ Experimental functions.
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