Jh. Kim et al., REGION-BASED WAVELET TRANSFORM FOR IMAGE COMPRESSION, IEEE transactions on circuits and systems. 2, Analog and digital signal processing, 45(8), 1998, pp. 1137-1140
Wavelet transform is not applicable to the arbitrarily shaped region (
or object) in images, due to the nature of its global decomposition. I
n order to solve this problem, the region-based wavelet transform (RWT
) is proposed and its computational complexity is examined in this bri
ef. It is shown that the RWT requires significantly fewer computations
than conventional wavelet transform, since the RWT processes only the
object region in the original image. Experimental results show that a
ny arbitrarily shaped region in images can be decomposed using the RWT
and perfectly reconstructed using the inverse RWT. Furthermore, the R
WT outperforms the shape-adaptive wavelet transform (SAWT) in PSNR at
the same compression ratio since the former generates less high-freque
ncy information.