2D and 3D surface texture comparisons using autocorrelation functions

Autocorrelation and cross-coffelation functions are proposed for 2D and 3D surface texture comparisons. At the maximum correlation point of the two correlated surface textures, there is a peak shown at the cross-coffelation curve. It is proposed to generate a difference function at the maximum correlation point for evaluation of the difference between the two compared surface textures. Based on this method, the National Institute of Standards and Technology (NIST) bullet signature measurement system is developed for the bullet signature measurements of NIST standard bullets.