Multi View Stereo - Mausoleum

Let's see if the downsampling factor that is used to compute disparity maps in Multi View Stereo 10 (MVS10) has much of an impact on the quality of the dense 3D reconstruction. It's important to know because computing disparity maps is quite time consuming, especially in MVS10 which computes two depth maps per image pair (to detect low-confidence disparities and therefore matches).

Set of eight 1080x1920 images/views for which we want to build a dense 3D reconstruction with MVS10.

Animated gif showing the dense 3D reconstruction produced by MVS10 using downsampling factor = 4 (and sampling step = 2).

A downsampling factor of 4 means that the original images are downsampled (shrunk) by a factor of two twice. This dense 3D reconstruction has 351,520 3D points.

Animated gif showing the dense 3D reconstruction produced by MVS10 using downsampling factor = 2 (and sampling step = 2).

A downsampling factor of 2 means that the original images are downsampled (shrunk) by a factor of two once. This dense reconstruction has 384,808.

Looking at the two animated gifs, there doesn't seem to be much of a difference between the two reconstructions. The conclusion is that downsampling images in order to compute disparity maps faster is a-ok (as long as you don't overdo it and downsample too much).