Automatically find a plate with a number on the photo

Question

Summary

On a photo taken from a tablet, you need to automatically find a plate with a number, and then recognize this number. In terms of the design of the plate, there is complete freedom. How best to arrange it, so that in different lighting conditions and regardless of the background of the photo, it would be possible with a high probability (90-95%) to find it.

For now, I've made a simple red bold border on a white background, with a small buffer around it. The problem is that the main criterion for the search is red, which will be greatly distorted depending on the lighting. I need to correct the white balance, but the automatic correction does not work well.

How would you design it, and what algorithms would you use to search for it?

Answer 1

Do you want to use a QR code ?

Answer 2

I advise you to download OpenCV and see examples. Leads to thoughts.
I downloaded EmguCV (http://www.emgu.com/) - this is a .NET wrapper. There are examples of recognition of license plates, plates and text.
In short, contours are searched (color is not important). If the photo is taken exactly (perpendicular to the sheet), then your plate can be determined by the proportions of the contour. If it's uneven, you can fix it. Next, remove the excess and recognize the text inside.