|Taking the previous page a step further let's
look at the practice of zenith/nadir patching and how it reduces noise.
again taking our test image , we'll now make two panoramas, one using a
single row of 3 images and another with an additional horizontal and
vertical patch image inserted. A rectilinear view of the zenith will then be
extracted from each panorama to compare the noise. The test image was
cropped to 170° prior to stitching to get an "expected" result from
||Single Row + Zenith/Nadir Patch
|Enlarged section of zenith
Notice that in the single row panorama the distortion of the noise is not
evenly distributed making it extremely difficult to filter/retouch.