Compression of signals in spectral domain consists in rejection of related transform coefficients and reconstruction of signals by inverse transform. There exist two basic methods used to select coefficients to be transmitted: Threshold Selection and Zonal Selection. In threshold selection the reconstruction is made with a subset of coefficients that are larger than a specified threshold. In zonal method the reconstruction is made with a subset of coefficients lying in predetermined zone. Only those coefficients are selected for further processing, the remaining coefficients are set to zero. In this paper, zonal compression technique performed on chosen signals using different transforms are investigated. The mean square error (MSE) is used as a measure of signal reconstruction quality. Plots of the MSE versus compression percentage are included for comparison of methods.
