Disparity is inversely proportional to depth. Information about depth is a key factor in many real time applications like computer vision applications, medical diagnosis, model precision etc. Disparity is measured first in order to calculate the depth that suits the real world applications. There are two approaches viz., active and passive methods. Due to its cost effectiveness, passive approach is the most popular approach. In spite of this, the measures are limited by its occlusion, more number of objects and texture areas. So, effective and efficient stereo depth estimation algorithms have taken the toll on the researchers. The important goal of stereo vision algorithms is the disparity map calculation between two images clicked the same time. These pictures are taken using two cameras. We have implemented the non-parametric algorithms for stereo vision viz., Rank and Census transform in both single processor and multicore processors are implemented and the results showsits time efficient by 1500 times.