Homework Assignment #9
Implement Borgefors Distance Transform
Original Paper:
G.Borgefors, Distance Transformations in Digital Images, Computer Vision, Graphics and Image Processing, 34, 344-371, 1986

In this homework you will implement the Borgefors distance transform which was discussed in class. The reference has been included in case you need to review anything. The command line to run the program is:
headfinder cola.ppm
findDistances is the one you are going to modify. In this function I've included a great deal of comments on what globals do what, what arrays you will need and some minor instructions on the algorithm itself.

You will need to properly initialize the distance array using the iEdges[][] global. Remember 0 distance is an edge, and infinite distance is a nonedge to start. An edge value is 255, so if(iEdge[i][j] == 255) mark	that pixel as 0 distance. You'll need to declare any variables you want to use. IE, the masks, i and j, etc.
If you implement the algorithm properly, your distances.pgm output should match the one provided.
Globals you'll need to know:
iEdge[][] //image edge(canny) image. 0 is a non edge, 255 is an edge