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JpgAlleg is a compact library written by Angelo Mottola in 2002/3 which loads and saves the most common type of JPEG image file. It has very few files and can be easy incorporated into your program.
JPGalleg is a small addon for Allegro that adds JPG images handling capabilities to the library. It is standalone, in that it doesn't require external packages; the library weights only 40K and allows you to load baseline and progressive JPGs, and to save baseline JPGs. Full integration with Allegro is provided, so you can use load_bitmap() and save_bitmap() on JPG files as if they were natively supported by the lib. The package comes with full sources, documentation and examples, plus a Grabber plugin so you can easily manage JPGs in your datafiles.
If you need to load or save more advanced kinds of jpeg files e.g. Jpeg2000, you need to use the industry standard Libjpeg
It is planned to merge JpgAlleg into Allegro 4.4