Based on JSquish library for DXT image compression by S. Brown, with small modifications in order to allow for concurrent calls to compression methods. Moreover, the ClusterFit algorithm was tweaked a little bit, which makes it about twice as fast.
Add this to build.sbt:
resolvers += "memo33-bintray" at "http://dl.bintray.com/memo33/maven"
libraryDependencies += "com.github.memo33" % "jsquish" % "2.0.1"