Lizardtech, Inc. v. Earth Res. Mapping, Inc., 424 F.3d 1336 (Fed. Cir. 2005), LizardTech sued Earth Resource Mapping (ERM) for patent infringement related to taking discrete wavelet transforms (DWTs) in their ER Mapper program. The court ruled in ERM's favor, finding that some of the claims were invalid, and that ER Mapper did not infringe the other claims. The case has been viewed as an example of the "written description doctrine" which courts may use when applying 35 U.S.C. § 112 to decide the validity of patent claims. Background LizardTech held US patent number 5,710,835 (the '835 patent) which covers a method for computing the DWT of a digital image with a limited amount of memory. LizardTech sued ERM, alleging that they infringed several of the claims in the patent. The University of California, being the record owner of the patent, was subsequently added as a party on the motion. LizardTech's patent In order to take the DWT of an image that is too large to fit in a computer's memory, prior art computer programs would first break the image into tiles, and calculate the DWT of each tile separately. Such a program only needs to fit one tile in memory at a time. However, when the filter is applied near the edge of a tile, the values which would normally have come from the neighboring tile are artificially set to zero. This introduces edge artifacts. The '835 patent solves this problem by computing DWT coefficients for pixels outside of the current tile, and then adding those values to the DWT coefficients computed for the adjoining tile. The resulting DWT is seamless. ERM's software ERM produced a software product called ER Mapper. ER Mapper included a memory-efficient algorithm to compute a seamless DWT. This algorithm did not work in exactly the same way as the patent's description: it first calculated the DWT coefficients in the row direction for all the pixels in each row of the image, and then proceeded to take the DWT of the resulting coefficients in each column. This required only one row or column to be loaded into memory at once. Procedural history On October 6, 1999, LizardTech filed suit against ERM in the Western District of Washington Court alleging infringement of claims 1, 13, 22–25, 27 and 28 of the '835 patent, among other charges. ERM filed a motion for summary judgement of non-infringement, arguing