Thx for the definition....and now i knew it.....

oh btw i have some problem again....

Is it true the focal length value is constant??? because i calibrated my camera once again and i have a different value of focal length......

I set up the Z= 160 cm so got the disp = 56 pixel and by the stereo vision formula i got

f=896 pixel, so after that i make a calculation with f=896 pixel and i got the value of Z from disp=1 to 255

But when the robot move in Z=80 cm (real condition) the disp was in 84 pixel and the focal length was changed too.... -->

f=672 pixel......based on my calculation if Z=80 cm the disp must be 89 pixel (with f=896 pixel) why it can be like that???

Pls tell me if i'm wrong......

thx