Comments on "A translation- and scale-invariant adaptive wavelet transform"

H. Xiong et al. (see ibid., vol.9, p.2100-8, 2000) presented a translationand scale-invariant adaptive wavelet transform. We show that their renormalized signal (pre-wavelet transform) is already translation- and scale-invariant. Thus, it is not just invariant under the wavelet transform. We give a necessary and sufficient condition for renormalized signals to be affine transform invariant.