US Patent 7801383 Embedded scalar quantizers with arbitrary dead-zone ratios

Embedded scalar quantizers for compression are described, along with tools for corresponding decompression. For example, a codec uses an embedded dead zone plus uniform threshold quantizer with repeated division of steps by specific factors. Non-dead-zone steps at a current level are divided into m+1 non-dead-zone steps at the next higher level, and the dead zone at the current level is divided into a dead zone at the next higher level with n new non-dead-zone steps at each side. Values for m and n depend on implementation. In some implementations, m=2 and n=1, and the dead zone ratio z=1, but other values are possible.