epeg.c.in

/** 
@file
@brief Epeg JPEG Thumbnailer library
 
These routines are used for the Epeg library.
*/

/**

@mainpage Epeg Library Documentation
@image html  epeg.png
@version 0.9.0
@author Carsten Haitzler <raster@rasterman.com>
@date 2000-2003

@section intro What is Epeg?

An IMMENSELY FAST JPEG thumbnailer library API.

Why write this? It's a convenience library API to using libjpeg to load JPEG
images destined to be turned into thumbnails of the original, saving
information with these thumbnails, retreiving it and managing to load the image
ready for scaling with the minimum of fuss and CPU overhead.

This means it's insanely fast at loading large JPEG images and scaling them
down to tiny thumbnails. It's speedup will be proportional to the size
difference between the source image and the output thumbnail size as a
count of their pixels.

It makes use of libjpeg features of being able to load an image by only
decoding the DCT coefficients needed to reconstruct an image of the size
desired. This gives a massive speedup. If you do not try and access the pixels
in a format other than YUV (or GRAY8 if the source is grascale) then it also
avoids colorspace conversions as well.

Using the library is very easy, look at this example:

@code
#include "Epeg.h"

int
main(int argc, char **argv)
{
   Epeg_Image *im;

   if (argc != 3)
     {
        printf("Usage: %s input.jpg thumb.jpg\n", argv[0]);
        exit(0);
     }
   im = epeg_file_open(argv[1]);
   if (!im)
     {
        printf("Cannot open %s\n", argv[1]);
        exit(-1);
     }
   
   epeg_decode_size_set           (im, 128, 96);
   epeg_quality_set               (im, 75);
   epeg_thumbnail_comments_enable (im, 1);
   epeg_file_output_set           (im, argv[2]);
   epeg_encode                    (im);
   epeg_close                     (im);
   
   return 0;
}
@endcode

You can compile this program with as small a line as:

@verbatim
gcc epeg_test.c -o epeg_test `epeg-config --cflags --libs`
@endverbatim

It is a very simple library that just makes life easier when tyring to
generate lots of thumbnails for large JPEG images as quickly as possible.
Your milage may vary, but it should save you lots of time and effort in using
libjpeg in general.

@todo Check all input parameters for sanity.
@todo Actually report error conditions properly.

*/