Abstract: An apparatus and method for signal, image, or video compression that achieves high compression efficiency in a computationally efficient manner and corresponding decoder apparatus and methods are disclosed. This technique uses zerotree coding of wavelet coefficients in a much more efficient manner than previous techniques. The key is the dynamic generation of the list of coefficient indices to be scanned, whereby the dynamically generated list only contains coefficient indices for which a symbol must be encoded. This is a dramatic improvement over the prior art in which a static list of coefficient indices is used and each coefficient must be individually checked to see whether a) a symbol must be encoded, or b) it is completely predictable. Additionally, using dynamic list generation, the greater the compression of the signal, the less time it takes to perform the compression.