Well, the only way is to win at trial. Can you argue that you really did stop? Can you argue that the crosswalk was improperly placed? Can you argue that the police officer's viewpoint was unreliable? Without knowing the facts of the case, it is tough to tell you how to go about trial. You may be very smart to hire a traffic ticket attorney to help you in trial.
You would either need to fight the ticket, go to trial and be found not guilty, or attend traffic school which hide the point from your record. You are eligible for traffic school if you have not gone in last 18 months which sounds like you have not.