Re: ts linearization algorithm

Hello,

> > > but now I see that at least h22xx doesn't. I don't know yet how a
> general
> > > transform equation should look like, but it will have to be more complex
> > > than just multiplying an 1x2 vector by a 2x2 matrix.
> > So I have tested another transformation to get a "linear" touchscreen. The
> > result is better but the constants still not optimal.
> The problem is that you try to describe an arbitrary curve with a
> second-order polynom. This is simply impossible, thus I doubt you will be
> able
> to get suitable results this way.

A remark about this point. This is true that a second order polynome is not
sufficient
to get a good approximation. But I think this is not exactly the problem : I get
better
results for some coefficients that do not follow exactly the curve. It seems
that the
touchscreen is very non linear in the corner. So if I ajust the polynom exactly
to the corner
I get the inverted convexity on the screen. Hence I have to find a ymin that is
less concave
to get better results.

I will try to get better result tomorrow.

I agree with all the other remarks of your mail.

Sincerely,

Alain
Received on Sat Apr 17 16:29:31 2004