Accuracy on Kitti dataset

[nivi1501]

Can I use Kitti 2015 dataset instead of Middlebury? With Kitti I am getting 3-pixel error of around 15-16%. Can you suggest methods to further reduce it. Also, can you please explain significance of these parameters:
// alpha
. pms_option Alpha = 0 . 9F ;
// t_col
. pms_option tau_col = 10 . 0F ;
// t_grad
. pms_option tau_grad = 2 . 0F ;
// Number of propagation iterations
pms_option. num_iters = 3 ;

Can I alter these parameters to reduce accuracy.