Recognizing License Plates from Digital Images

Abstract

This thesis researches possibility to detect and recognize car license plates from digital images produced with Nokia N70 cameraphone's camera. Recognized plate number is then sent over the GSM-network as an SMS to an Internet database-server, from which details of the car are returned into the screen of the phone.

Thesis first introduces reader to image processing operations needed in the process, then moves on to describe the structure of feedforward neural network and teaching it using backpropagation of errors. After this we get into how this system can be implemented in practice.

The aim is to achieve a 50% reliability in recognizing license plates, which means that on average, on every second occasion, the license plate is recognized correctly. The second aim is to develop efficient image processing methods for S60 Platform, that could later be used in applications that utilize a phone camera. Finally, the purpose of the thesis is to find out how well is it possible to do optical character recognition using a modern mobile phone.