Introduction - If you have any usage issues, please Google them yourself
Hough Transformation is used for searching lines in an image . Here is the principle:
Assume there is a line whoes direction is "sita" , and the distance from the origin to this line is s. So each point in this line satisfies the equation : s=x*Cos(sita)+ y*Sin(sita) . We can find out the lines based on this fact.
And this programme is to find out the longest line in the image.