Edge Preserving Smoothing 9 (EPS9)

Edge Preserving Smoothing 9 (EPS9) is a variant of the bilateral filter. In the bilateral filter, weights are given to the pixels within a window centered around a given pixel such that pixels that are closer to the center pixel in terms of distance and color have more weight than the others. This kinda guarantees that smoothing occurs within the immediate neighborhood of the center pixel and only involves pixels of similar color to the center pixel. A median filter is used to determine which depth in the neighborhood of the center pixel should be adopted. The idea is to get rid of (annoying) outliers in the depth map.

The parameters that control execution are:
- Window radius. The larger the window radius, the more pixels are involved in the smoothing process of a given pixel (the one at the center of the window).
- Sigma space. This affects the weight that comes from the spatial distance (distance from pixel to center pixel in 2d space).
- Sigma color. This affects the weight that comes from the color distance (distance from pixel to center pixel in color space).

Here is an example:

Reference image (left view of Tsukuba pair).

Input depth map that we wish to smooth out a bit.

Output depth map smoothed by EPS9.

The windows executable (guaranteed to be virus free) is available for free via the 3D Software Page.