% Images with only vertical or horizontal features are preserved
% when performing 'no-op" with EWA distortion.
%
-% EWA LanczosSharp does not satisfy this condition exactly, but it
-% comes really close: If all the data is in [0,1] and the input image
-% is constant on columns (or rows), EWA LanczosSharp preserves the
-% image under no-op to within 0.00465 (that is, it is off by at most
-% 2 in 8-bit); EWA Lanczos, on the other hand, preserves it to within
-% 0.0174 (5 in 8-bit). The preservation of arbitrary images under
-% no-op, however, is not so good: EWA Lanczos preserves it to within
-% 0.308 (79 in 8-bit), EWA LanczosSharp to within 0.315 (81 in
-% 8-bit). In particular, 'pixel-hash' patterns (the checkerboard
-% mode) are smoothed out a lot.
-%
% The Lanczos2 and Lanczos2Sharp filters are 2-lobe versions of the
% Lanczos filters. The 'sharp' version uses a blur factor of
% 0.958027803631219, again chosen because the resulting EWA filter