Constrained with structures of the meter panels, the automatic measurements are required to take different ways. In this paper, a new approach to the automatic measurement of voltmeter with a cylindrical panel and nonlinear scale is presented. Firstly, one real-time image captured by a camera is processed to locate the region of the pointer and the scales. Secondly, according to the shape features of the dial, a 5×1 filter is adopted to reduce the noises, then a thinning algorithm is applied to extract the framework of the pointer and the scales, and a thinning correction algorithm is used to compensate for the slight deflection of pixels. Thirdly, a method for cylindrical rectification is used to compute the precise position of the pointer and the scales. Finally, error sources are discussed. Experimental results show that this system is of speediness and errorless and can meet the engineering requirements.