Electric Meter Readings


We have developed a system capable of reading the displayed value of the mechanical register of electrisity meters, with a high precision, similar to that of human operator. That means, that the system must be able to relyable determine at least 100 discrete positions of the right most register wheel, and it maust also tolerate missing parts of the numerals. It is clear that classic OCR methods do not provide an adequate solution. They can only read discrete values, e.g. 2 or 3. They cannot read 2.2; neither can reliably recognize partly visible symbols.
Briefly, the reading of the maechanical register is accomplished by analyzing the visible part of the digits. First, the rotary counter is located and segmented into regions containing individual wheels or digits. Next, the isolated wheels are read, independently of each other. The wheel positions aredetermined with accuracy of two decimal digits, e.g. 3.3. The right-most place is output is output as computed, and the other decimal places are derived simply by "truncating" the fractional part, with an exception when the wheel position "overflows" from 9 to 0.



Boštjan Murovec, Matej Kniewald, Stanislav Kovačič, "Optical Reading of Electricity Meters", Pattern Recognition 1997, Proceedings of the 21st Workshop of the Austrian Association for Pattern Recognition, eds. Wilhem Burger, Mark Burge, pp. 255-263, Hallstatt, Upper Austria, May 26-27, 1997.