How to load a gif image or one that has LZW compression.

Problem:

• An image that has been stored with LZW compression can not be loaded in ArcMap or viewed in ArcCatalog without having a license to do so.  We do not have a license.  LZW compression is used in all GIF images, and Photoshop and other software provides a way  of saving compressed TIFF images in this format.

Solution:

• Bring the image into Photoshop and save it without LZW compression in a format that is readable by ArcMap.  If the image is accompanied by a world file (a file giving the coordinates of the upper left pixel and the image resolution, usually with the extension .XXw, where XX denotes the image format, e.g. jpw for JPG or .tfw for TIFF) then be careful that the resolution of the new file is the same as the old.  This can be a problem because the default resolution used by Photoshop for many image formats is 72 dpi - the image is loaded at this resolution regardless of its native resolution and size.  Check the Image Size (Image>Image Size...) and adjust as necessary before saving.