How to implement recognition of letters drawn in canvas?

Question

PHP

isc.96.lt/en/?view=p/abc/2_b
On the 5th tab, the letter A is drawn on the canvas, how to send a screen to Google so that it returns the answer what is drawn, what letter?
or wherever you can.
I want to do it on the client side, it is desirable that the delay be no more than 4 seconds.
Or maybe a script in php or on which there is one that recognizes how to throw this on a server as an option.
Yandex did not recognize something (

Answer 1

Look for captcha solvers)))