Convert x3f to dds Online: x3f2dds
You can use Tom's Editor to easily convert images from
Sigma Camera RAW Picture File .X3F to Direct Show Surface
Tom's Editor is a free, online image manipulation and converter program.
Go to Tom's Editor
Sigma Camera RAW Picture File is an image format with extension X3F.
DDS are files invented by Microsoft to be used in games, mostly as textures. Images can be compressed to save space but the compression methods defined by DDS are all very fast in terms of coding and decoding.