Convert bm to dds Online: bm2dds

You can use Tom's Editor to easily convert images from
VBM/VDC BitMap .BM to Direct Show Surface .DDS.
Tom's Editor is a free, online image manipulation and converter program.

Go to Tom's Editor

BM

VBM/VDC BitMap is an image format with extension BM.

DDS

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.