I require to find the number of DSL (Digital Straight Line) in any given alphabet. For example A.

The conditions to be fulfilled for a point to be DSL are:

1) There exist runs of pixels in at most 2 directions which differ by 45degree.

2) For runs of 2 directions,the run lengths in one of the directions

is always one.

3) The run length in the other direction can have at most 2 values

differing by unity(e.g. n and n+1).