As iphonejudy had already been told on these forums, more than once, that that specific header was not available on the iPhone I felt it was necessarily rude. In addition the level of question posted by this individual demonstrates their apparent competence well.
With respect to pointers I'd suggest the phrase "world of pain" and this
technical Q&A. Once you have the raw pixels you can manipulate them at a byte level taking care to respect the various parameters like bytes-per-row, bits-per-component and so on. As I said "world of pain".