[rouli]

really nice! in your fitness function - wouldn't you prefer to normalize somehow for the the line's length? i.e. - longer lines (going between two far away pins) will cover more dark pixels, and are more likely to be picked, even though they might also cover many bright pixels. I wonder if the average darkness of pixels along the line will work better?

[theveloped]

Normalizing would most likely only change the order of chosen paths. I do feel there would be something to be gained from penalizing the crossing of light areas. I there say this would increase the quality of finer details.