CAPTCHA Recognition Model Training Guide: From MNIST Dataset to Real Scenarios

Why do you always get stuck at the first step of the CAPTCHA recognition process?

Machine learning friends understand that practicing with MNIST dataset is like eating instant noodles - simple and fast but not nutritious. The real scene of the CAPTCHA will be deformed, add noise, background interference, and then you will find that the trained model is like a blind. The key problem isReal Data AcquisitionMany websites prevent crawlers and thieves like, even request a few times to give you IP off the small black house.

This is the time to rely on proxy IP to break the game. Take our own ipipgo dynamic residential agent, each request automatically switch real home network IP, with the request interval settings, data collection success rate directly tripled. Don't be silly with the data center IP, now the website anti-climbing mechanism is fine, the data center IP segment has been marked rotten.

Hands-on tutorial: hand-feeding the model to you

Let's be clear. We're going to do this in three steps:

Focus on the second stage. Remember to add the proxies parameter to the requests when writing a crawler in Python. ipipgo's proxy address format is http://用户名:密码@gateway:port. As an example:

proxies = {
  "http": "http://vipuser:123456@gateway.ipipgo.net:9021",
  "https": "http://vipuser:123456@gateway.ipipgo.net:9021"
}
response = requests.get(url, proxies=proxies, timeout=8)

The wild card of model tuning

Don't just focus on accuracy, real life scenarios have to be seenanti-interference capabilityThe first thing you need to do is to use ipipgo to collect the same source of data. Teach you a tawdry operation: the collection of CAPTCHA first through the image enhancement (rotate, distort, add noise), and then use ipipgo different regions of the IP and then collect the same source of data, so that the trained model is like an old driver, see more.

Have you ever encountered this situation? The model tests well locally, but then it goes online. It is likely that the IP fingerprint is recognized, and you have to change the ipipgo.Highly anonymous agents, wiping both the X-Forwarded-For and Via headers from the request header to make the target site think it's a real person operating.

Guide to Avoiding the Pit: Three Minefields for Newbies

1. IP switching too oftenDon't cut the IP every second like a wind, the site is not stupid, it is recommended that according to the strength of the target station's anti-climbing set 5-30 seconds / times the frequency of switching!

2. Ignore IP geolocationSome CAPTCHAs will change their style depending on the location of the visitor, so remember to check the box in the ipipgo backend!Multi-region IP Hybrid Acquisition

3. Dead set on a single CAPTCHA type: When it comes to particularly difficult CAPTCHAs (e.g. Google's reCAPTCHA v3), it's time to get on board with behavioral simulation, so don't be ironic!

QA time: what you might want to ask

Q: What should I do if my IP is always blocked for collecting data?
A: Check three points: 1. whether the residential proxy is used 2. whether the request header is complete 3. whether the operation interval is regular. It is recommended to use ipipgo's intelligent routing mode to automatically avoid high-risk IP segments.

Q: Slow response after deployment of trained model?
A: 80% is the problem of image pre-processing, try to do image binarization processing on the proxy server side, the transmission volume can be reduced by 90%. ipipgo's enterprise version supports edge computing, this feature thief is good to use.

Q: How many proxy IPs are needed to be enough?
A: Depends on the size of the business, small and medium-sized projects with ipipgo's elastic IP pool (5000 + dynamic IP) enough. There is a formula: the average number of IPs required per day = the expected number of requests / (target station IP blocking threshold × 0.7)

As a final rant, now that CAPTCHA technology is upgraded every three months, the secret to keeping the model alive is toContinuous data feeding + reliable proxy IP supportI'm not sure if you're going to be able to get it. Our ipipgo has recently launched a special channel for CAPTCHA, if you need to find the customer service to test the amount, report the code "CAP2024″ can send 20% more traffic.