In a printed script, the text lines are almost of same
height, provided that the script is written in a specific font
size. If the script is composed by a type-machine, surely the
font size will be uniform everywhere. Between two text
lines, there is a narrow horizontal band with either no pixel
or very few pixels. Hence, by checking break-points
through them and storing them will be useful for detecting
the valleys in it, text line bands can be retrieved