replacing NSImage reps

gistfile1.m

NSImage *iRep = [NSImage imageNamed:[fileName stringByDeletingPathExtension]];

if (iRep) {
    
    NSImage *ni = [[NSImage alloc] initByReferencingFile:output];
    
    for (NSImageRep *r in [[iRep representations] copy]) {
        [iRep removeRepresentation:r];
    }
    
    [iRep addRepresentations:[ni representations]];
}