Fix crash in CreateImage
Fix crash in CreateImage

@chhabragarima It was a dereference of an optional input. Like a pointer, these need to be checked if they are non-empty before derefence and use.

jessdtate/SCIRun,moritzdannhauer/SCIRunGUIPrototype,jessdtate/SCIRun,jessdtate/SCIRun,jessdtate/SCIRun,moritzdannhauer/SCIRunGUIPrototype,moritzdannhauer/SCIRunGUIPrototype,moritzdannhauer/SCIRunGUIPrototype,jessdtate/SCIRun,jessdtate/SCIRun,moritzdannhauer/SCIRunGUIPrototype,jessdtate/SCIRun,moritzdannhauer/SCIRunGUIPrototype,moritzdannhauer/SCIRunGUIPrototype,jessdtate/SCIRun