Unweave removes weaving artifacts from images by removing the odd or even field and interpolating it from the other field. Many programs call this "deinterlacing", but that's wrong. The following images should make things clear.
Original - 8x Magnification
Copy unweaving - 8x Magnification
Linear unweaving - 8x Magnification
Among other features, unweave supports different interpolation methods, and can auto-detect whether an image has weaving artifacts or not.
You may use Unweave under the terms of the GNU General Public License, version 2.
Unweave is documented in its manpage.