Implementation of BOUNDARY FOLLOWING (TRACING)

by the descriped steps from Digital Image Processing 4th Edition Rafael C. Gonzalez Richard E. Woods

See also: http://www.imageprocessingplace.com/downloads_V3/root_downloads/tutorials/contour_tracing_Abeer_George_Ghuneim/moore.html

Sample images from: https://archive.ics.uci.edu/ml/machine-learning-databases/00241/

##calculate signature of boundary

• https://www.math.uci.edu/icamp/summer/research_11/klinzmann/cdfd.pdf
• https://users.monash.edu.au/~dengs/resource/papers/accv_fd.pdf
• https://en.wikipedia.org/wiki/Centroid#Of_a_polygon