Skin rough ness (R1) is defined as the difference between the highest crest and
lowest furrow. To exclude the possibility of artifact, the program cut the line into five equal parts. R3 represents an average of the maximum distance (R1) derived from each of the five parts of the line. R2 represents the largest value of these five distances. R4 represents the mean area surrounded by a horizontal line drawn at the highest crest and the furrows profile. R5 stands for the mean deviation of the furrow’s profile to the middle line.