FPGA implementation of short critical path CORDIC-based approximation of   the eight-point DCT
  This paper presents an efficient approach for multiplierless implementation for eight-point DCT approximation, which based on coordinate rotation digital computer (CORDIC) algorithm. The main design objective is to make critical path of corresponding circuits shorter and reduce the combinational delay of proposed scheme. 
Maxim Vashkevich, Marek Parfieniuk and Alexander Petrovsky
cs.AR