LZW
From The Glossary of Digital Photography
An abbreviation for Lempel-Ziv-Welch, a lossless data compression technique. LZW is used in the GIF format, within the Adobe Acrobat format, and, optionally, with TIFF images. Savings in size can be as high as 50%. With the TIFF format, the compressed image may show small or even negative data compression, depending on the image. TIFF-LZW is not widely used, although Photoshop offers that option when saving images as TIFF files. Not all programs support TIFF-LZW. See also GIF; Acrobat
