J. Harris and S. N.J. Watamaniuk. Speed discrimination of Motion-in depth using binocular cues. Vision Research, 35(7):885-896, 1995.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....A moving object in the 3 D space projects different trajectories onto the lef and right retinas. The differences between the two trajectories carry information about motion in depth. Thus, the Z component of the object s motion (i.e. its motion in depth) Vz can be approximated in two ways [1]: 1) by the rate of change of disparity, and (2) by the difference between retinal velocities, as it is evidenced in the box in Fig. 1. The predominance of one measure on the other one corresponds to different hypotheses on the architectural solutions adopted by visual cortical cells to encode ....

....contribution for the ipsilateral eye and a non dominant contribution for the controlateral eye. These contributions are referable to binocular disparity energy units [5] built from two pairs of binocular direction selective simple cells with left and right RFs weighted by an ocular dominance index [0, 1]. The tilted spario temporal RFs of simple cells of the model are obtained by combining separable RFs according to an Addson and Bergen s scheme [9] It can be demonstrated that the information about motion in depth can be obtained with a minimum number of eight binocular simple cells, four with ....

J. Harris and S. N.J. Watamaniuk. Speed discrimination of Motion-in depth using binocular cues. Vision Research, 35(7):885-896, 1995.

....as I(x) IR[x 5(x) where 5(x) is the (horizontal) binocular disparity. If an object moves from P to Q its disparity changes and projects different velocities on the retinas (v, vR) Thus, the component of the object s motion (i.e. its motion in depth) Vz can be approximated in two ways [1]: 1) by the rate of change of disparity, and (2) b(t) xVcxV, a(D Zv) D 2 (t At) xOcxO) a(D Zo) D2 Vz = Ab D2 a A = t At) t) At At (xe xO (x x ) v:v V z (vcv)D2 a XL XR a Figure 1: The stereo dynamic correspondence problem. A moving object in the D space projects ....

....whereas the darker gray blob represents the car moving away. The background gray level codes all the static elements present in the scene. 5 Discussion and conclusions There are at least two binocular cues that can be used to determine the motion of an object toward or away from an observer [1]: binocular combination of monocular velocity signals or the rate of change of retinal disparity. Assuming a phase based disparity encoding scheme [4] we demonstrated that informa tion hold in the interocular velocity difference is the same of that derived by the evaluation of the total ....

J. Harris and S. N.J. Watamaniuk. Speed discrimination of Motion-in depth using binocular cues. Vision Research, 35(7):885-896, 1995.

....A moving object in the 3 D space projects di erent trajectories onto the left and right retinas. The di erences between the two trajectories carry information about motion in depth. Thus, the Z component of the object s motion (i.e. its motion in depth) VZ can be approximated in two ways [1]: 1) by the rate of change of disparity, and (2) by the di erence between retinal velocities, as it is evidenced in the box in Fig. 1. The predominance of one measure on the other one corresponds to di erent hypotheses on the architectural solutions adopted by visual cortical cells to encode ....

....one. A decrease of the inhibition strength yields cells characterized by a less selective response to direction in depth, whereas an increase of diminishes their response amplitude. 4 Discussion and conclusions There are at least two binocular cues that can be used to determine the MID [1]: binocular combination of monocular velocity signals or the rate of change of retinal disparity. Assuming a phase based disparity encoding scheme [6] we demonstrated that information held in the interocular velocity di erence is the same of a y e r 2 ( o c u l a r d o m i n ....

J. Harris and S. N.J. Watamaniuk. Speed discrimination of Motion-in depth using binocular cues. Vision Research, 35(7):885-896, 1995.

....assets of the approach can be considered under di erent perspectives: modeling, computational, and implementation. Modeling: Psychophysical studies evidenced that perception of MID can be based on binocular cues such as interocular velocity di erences or temporal variations of binocular disparity [11]. The predominance of one measure on the other one corresponds to di erent hypotheses on the architectural solutions which evolved, by nature, in the visual cortex. We demonstrated analytically that information hold in the interocular velocity di erence is the same of that derived by the ....

J. Harris and S. N.J. Watamaniuk. Speed discrimination of Motion-in depth using binocular cues. Vision Research, 35(7):885-896, 1995.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC