Abstract: Curve fitting is a very important descriptor in image analysis, the most commonly used curve fitting method is least squares method. But ordinary least squares method has some limitations, and there are many scholars have made study of improving it. The authors made further improvement on least-squares method and proposed a new piecewise linear fitting algorithm instead of polynomial curve fitting. The new algorithm achieves the goal of simplifying the mathematical model, reducing the calculation, and makes it better to fit point sequence.

Key words: Linear fitting,Lcast-squares method,Piccewisc