Abstract
A new method for fabric imaging,the sub-band exchange algorithm, has been developed using the wavelet packet decomposition. It is an algorithm which synthesizes the artifical signals by recombining the basic time-frequency components obtained from the wavelet packet decomposition. The resulting coefficients are exchanged between time-frequency bands according to their energy level. the procedure allows us to control the vaiability of the densities which may exist in yarn samples in a systematic way. It also provides a new way of synthesizing the data sets sufficient for the realistic fabric imaging froma limited number of the given data sets.