Abstract
In this paper, we propose a system for automatic reading of an analogue meter using a digital image which is flexible and allows easy installation for various existing analogue meters. The system operates segmentation of meter area from a image, correcting image distortion and recognition of the scale on the meter in automatic setup phase. And it operates meter reading in monitoring phase. In our system, the planer projective transformation is automatically applied to a distorted image using a rectangle and a circle, to correct geometric distortion. In the automatic setup phase, the graduation marks of the scale are detected and located from a acquired image. Thereby, the meter reading can be flexibly adapted to different meter scales during the easy process. In the monitoring phase, the needle is detected and located from a new acquired image, and the meter reading is derived by comparing the relative position of the needle within the arrangement of the detected graduation marks. The experimental results show that the proposed system realizes automatic reading for various analogue meters as exactly as human observers under the controlled illuminated condition.
