Illustrator convert images into strings for embedding in scripts (copied from ScriptUI for dummies: http://www.kahrel.plus.com/indesign/scriptui.html), page 122.

graphic_to_text.jsx

function graphic_to_text(infiles) { // Array of file objects. 
	var outfile,
	    s,
	    re1 = /^\(new String\(/,
	    re2 = /\)\)$/;
	for (var i = 0; i < infiles.length; i++) {
		if (infiles[i].exists) {
			outfile = File (infiles[i].fullName.replace (/\.(png|idrc)$/, '.txt'));
			outfile.open ('w');
			infiles[i].encoding = 'BINARY';
			infiles[i].open('r');
			s = infiles[i].read();
			outfile.write('var ' + outfile.name.replace ('.txt', '') + ' = ');
			outfile.write(s.toSource().replace(re1, '').replace(re2, ''));
			outfile.write(';');
			infiles[i].close();
			outfile.close();
		}
	}
}
graphic_to_text (Folder ("/d/test/").getFiles ("*.png"));
graphic_to_text ([File ("/d/test/iconA.png"), File ("/d/test/iconB.jpg")]);
graphic_to_text ([File ("/d/test/iconC.idrc")]);