Unfortunately bypassing CAPTCHAs programmatically is almost always against terms of service of most websites, and can even be possibly illegal depending on the jurisdiction.
You also have to realize that CAPTCHA is built specifically to deter what you are trying to do, get past certain authentication barriers programmatically. Even if you were to find a solution, it would be in the best interest of the CAPTCHAs developers to immediately patch it, thus all solutions would be fairly impermanent and unreliable.
If you are specifically trying to bypass CAPTCHA during testing for your own site, there should be alternative paths to bypass the CAPTCHA. It would depend on your service but many provide automation and testing tools such as test keys, otherwise you can disable the CAPTCHA in your testing environment.