80 / 2015-12-08 10:44:51

A Size Measurement System Based on Wavelet Spline Subpixel Algorithm

As an important method of on-line detection, image detection is more and more applied in industry. In image size measurement system,it is a problem that the measurement accuracy depends mainly on the physical resolution of the camera. To solve this problem in the workpiece’s image measurement system,this paper proposes a subpixel-accurate edge detection algorithm based on wavelet transform with the cubic spline interpolation. Firstly, calculate the wavelet modulus maximum,and detect the pixel-accurate edges. Then apply the cubic spline interpolation to obtain subpixel-accurate edge at the side of the pixel-accurate edge. Finally,the reliability of this method is studied,some experiments are conducted to demonstrate the effectiveness of this size measurement method.Comparing with the traditional methods, this method has a good anti-noise performance with high size measurement accuracy and little size deviation (about 0.007mm).