How to automatically detect runner numbers in an image?

Question

PHP

There are photos of runners from sporting events. There are hundreds of photos each time. There is a task to determine which runners with which numbers are in the photo. A solution that can be used from a php script (for example, after uploading a photo to the server) is simply the ultimate dream. Regarding partially closed numbers (angle, runner's hands), it is possible to initially place some code on the number indicating the number of digits on the number, to ignore triggers when part of the runner's number is closed from the camera.

Answer 1

attach the qr code to the runners

Answer 2

The task can be divided into two parts:
1) segmentation - search for areas of the image with numbers
2) recognition of numbers in these areas
The first task can be solved in several ways:
- OpenCV - search for rectangular areas using Hough transforms
- search using the Viola-Jones algorithm, primitives Haar (see for example https://habrahabr.ru/company/recognitor/blog/228195/)
- using machine learning. But for this, you must first train the network on the labeled set
. After that, you can proceed directly to the recognition of numbers on the found fragments.
Here you can use neural networks, or your own heuristic algorithms. And you can transfer it to the anti-captcha service - decaptcher.com, pixodrom.com , antigate.com , but it will be paid; see where it will be cheaper and faster