Polygonal Approximations by Newton's Method

The problem of locating optimally the breakpoints in a continuous piecewise-linear approximation is examined. The integral square error E of the approximation is used as the cost function. Its first and second derivatives are evaluated and this allows the application of Newton's method for solving the problem. Initialization is performed with the help of the split-and-merge method [8]. The evaluation of the derivatives is performed for both waveforms and contours. Examples of implementation of both cases are shown.