
208
Applying the Hough transformation on the full
image results in a ρ, θ array with the number of
occurrence as third parameter, see (Fig. 21).
The largest amount of occurrence (number of
pixel which contributed) is 969 at ρ = -179 and
θ = -64. The inverse transformed line parts are
shown in Fig. 21.
2.4 Extracting power lines
The last step is to extract the power lines. The prop-
erty of a power line is that the distance between
its edges is very small (less than 0.5% of the image
diagonal) and their orientation is nearly the same.
In the Hough matrix the distance is defined by the
ρ-value and the orientation by Θ. All peaks, out of
50 highest ...