The DDS (DirectDraw Surface) container file format, from Microsoft, is a standard for storing data compressed with the lossy S3 Texture Compression (S3TC) algorithm.[1] This makes the format useful for storing graphical textures and cubic environment maps as a data file, both compressed and uncompressed. Textures in SimCity 2013 are typically stored in DDS format, and are packaged together with RW4 geometry files to create in-game 3D objects.
DDS Plugins[]
Photoshop
DDS Support & Texture Tools for Photoshop
GIMP