Fig. 2.

Error in fiber orientation measurements with respect to fiber thickness and window size used for the vector summation measurements. Beyond a thickness of 5 pixels, error in fiber orientation measurements began increasing exponentially when fiber thickness increased beyond the window size used for detection. Standard deviation of the average difference in angles was on the same order of magnitude as the mean value, but is not plotted in the graph in order to aid in viewing the overall effects of thickness and window size.