finding moving direction of object?

 according to diagram, i have an object in time 't' with a special position and in 't+1' in which it moved to another position, how can I find the moving direction? these spot (blue and red) are an object in two binary images (time 't' and 't+1')

Answer 1

[Thorsten]

If the object has position (x1, y2) at time t and (x2, y2) at time t+1, it moved in the direction (x2 - x1, y2 -y1).

[Abo]

for instance, the first position was (2,4) and the second one (4,6), regarding your answer: result is (2,2). in the second example, if the object move from position (4,6) to (2,4) we have: (-2,-2). how can I find direction according to your answer in matlab?

[Thorsten]

P1 = [2 4]; P2 = [4 6];
D = P2 - P1;

[Abo]

thank you for your answer. please let me know how can I draw this direction and how can I define this direction as positive or negative?

[Thorsten]

In general you should start a new question if you have a new question. In this case I answer it anyway: Draw an arrow from P1 to P2, google it if you don't know how to draw arrows in Matlab; and the values you get could be positive or negative... That gives you some idea how to define a direction as positive or negative :-)