There are many solutions for bank card number recognition on the market, and the ones that have been found and tried are as follows.
1. Baidu Lab http://apistore.baidu.com/apiworks/mservicedetail/1835.html
2. Yunmai http://www.yunmai.com/
3. Hanvon http://developer.hanvon.com/
Generally divided into api and sdk, api is relatively simple, but you need to send the image address or send the image to the cloud; sdk can process local images, and the speed will be faster.
There are free versions, but they are limited to about 20 daily calls and cannot be commercialized. The approximate price of the commercial version is about 0.1 yuan per time, and it can be cheaper if the quantity is large.
Bank card recognition is more difficult than ID cards, if the open source solution mainly uses the powerful visual library opencv to process pictures. For java developers, there is also a three-party package javacv for calling the opencv library, which is quite interesting. I have recently studied this.