针对跨尺度数据之间尺度差异导致拼接困难、精度低等问题,提出了一种使用分形维数表征尺度的跨尺度数据拼接方法。利用离散小波变换对原始数据进行多尺度分解,获取其在多个尺度上的近似数据,并采用分形维数对数据之间的尺度差异进行表征与衡量,找出跨尺度数据在相近尺度上的小波变换数据;而后通过迭代最近点算法对获取的尺度近似数据进行拼接。最终将所获得到的转换关系应用于原始数据,完成跨尺度数据的拼接。对获取的不同尺度下的三维表面形貌数据进行分形维数的计算,结果表明,分形维数能有效表征以及衡量尺度参数。跨尺度拼接结果表明,所提出的方法能有效地实现跨尺度的数据拼接。

In order to solve the problem of difficulty and low accuracy of registration between cross-scale data, we propose a cross-scale data registration method based on fractal dimension characterization. The discrete wavelet transform algorithm is used to decompose the raw data to obtain its approximation at each scale. Then the fractal dimension is adapted to characterize the scale parameter of the decomposed data. According to the fractal dimension, we pick out the scale-approximated data from different raw data, using iterative closest point algorithm for fine registration as a usual case. The calculation result of fractal dimension at different scales shows that the fractal dimension can represent scale parameters effectively. And the registration results indicate that the proposed registration method can achieve the registration of cross-scale effectively.