By looking at your enhancements to the original $1, I was able to improve my own attempt at a $1 recognizer. As you point out, it confused '+' and 'x' as well as many others. The key was handling orientation sensitivity by NOT rotating the point arrays of gestures. And, as you also point out, the use of non-uniform scaling was messing up straight lines. Best!
By looking at your enhancements to the original $1, I was able to improve my own attempt at a $1 recognizer. As you point out, it confused '+' and 'x' as well as many others. The key was handling orientation sensitivity by NOT rotating the point arrays of gestures. And, as you also point out, the use of non-uniform scaling was messing up straight lines. Best!