lomo effect and shader

Michele Verità's icon

dear all i would like to write a jitter patch that replicates the lomo picture feel (vignette, slightly chromatic and lens aberration..)..and than i woulf like to write a shader too..any advise tips and tricks..anyone have already made it..this could be pretty straightforward for some of you..
any helps greatly appreciated
michele
ciao

Michele Verità's icon

..my first idea
a little rgb separation
some jit.bfg => jit.op * for vignettetting