Hm, I think an easy way to circumvent this style of captcha with a small amount of work would be to just send every iteration to Google as a reverse image search and pick the iteration with the most results.
- Non-distorted image: http://goo.gl/R3WnQ This is the "perfect" choice and also returns a good amount of search results.
- Slightly distorted image: http://goo.gl/G0xQN This results in a "human" choice on the picker and picks up a fair number of search-results.
I imagine 15-20 searches per captcha, but if you just pick the best per set you're probably going to end up with adequate results in circumventing the system.
For example:
- Distorted image: http://goo.gl/w2ykx (bad results, not human)
- Non-distorted image: http://goo.gl/R3WnQ This is the "perfect" choice and also returns a good amount of search results.
- Slightly distorted image: http://goo.gl/G0xQN This results in a "human" choice on the picker and picks up a fair number of search-results.
I imagine 15-20 searches per captcha, but if you just pick the best per set you're probably going to end up with adequate results in circumventing the system.