Using Edge Preserving Smoothing 9 (EPS9) to smooth out depth maps

In this post, I would like to show what happens when Edge Preserving Smoothing 9 (EPS9) is applied to a depth/disparity map in the hopes of improving its quality.

I used these parameters in EPS9 for all depth maps:
radius = 9
sigma space = 9.0
sigma color = 25.5

The depth maps were obtained with Depth Map Automatic Generator 2 (DMAG2). See Depth Map Automatic Generator 2 (DMAG2) vs Depth Map Automatic Generator 5 (DMAG5)) for more information.

Depth map 1:

Left image after epipolar rectification.

Left depth map produced by DMAG2.

Left depth map smoothed by EPS9.

Depth map 2:

Left image after epipolar rectification.

Left depth map produced by DMAG2.

Left depth map smoothed by EPS9.

Depth map 3:

Left image after epipolar rectification.

Left depth map produced by DMAG2.

Left depth map smoothed by EPS9.

Conclusion:

Looks like EPS9 does a great job at removing tiny outliers in depth maps. Because it is edge preserving, it also maintains object boundaries.