Relation To Direction
A line between two points p1 and p2 has no given direction, but has a well-defined orientation. However, if one of the points p1 is used as a reference or origin, then the other point p2 can be described in terms of a vector which points in the direction to p2. Intuitively, orientation can be thought of as a direction without sign. Formally, this relates to projective spaces where the orientation of a vector corresponds to the equivalence class of vectors which are scaled versions of the vector.
For an image edge, we may talk of its direction which can be defined in terms of the gradient, pointing in the direction of maximum image intensity increase (from dark to bright). This implies that two edges can have the same orientation but the corresponding image gradients point in opposite directions if the edges go in different directions.
Read more about this topic: Orientation (computer Vision)
Famous quotes containing the words relation to, relation and/or direction:
“Whoever has a keen eye for profits, is blind in relation to his craft.”
—Sophocles (497–406/5 B.C.)
“The instincts of the ant are very unimportant, considered as the ant’s; but the moment a ray of relation is seen to extend from it to man, and the little drudge is seen to be a monitor, a little body with a mighty heart, then all its habits, even that said to be recently observed, that it never sleeps, become sublime.”
—Ralph Waldo Emerson (1803–1882)
“The young ... look into visages dull-eyed, long-toothed, wattle-necked, and chop-fallen, something they have never been and which they cannot imagine ever being.... If it occurs to a young person, looking at us, that this is the direction in which he himself travels, how can he forgive, let alone bear the sight of, us, who constantly bring him the bad news of our own faces, bitter signposts pointing to his own destination?”
—Jessamyn West (1902–1984)