This is the respository for Matlab implementation of 4D (4 dimensional) discrete wavelet transform and the corresponding inverse transform by Tommi Heikkilä (University of Helsinki, Department of Mathematics and Statistics).
Excellent book on anything wavelet related is "A wavelet tour of signal processing". Elsevier, 1999 by Stéphane Mallat.
This implementation is more or less an extension of the 3D discrete wavelet transform and inverse (wavedec3 and waverec3 respectively) by M. Misiti, Y. Misiti, G. Oppenheim & J.M. Poggi for the Wavelet Toolbox.
Just like the lower dimensional wavedec implementations (which are included in Wavelet Toolbox) these functions require the Matlab's Wavelet Toolbox to work properly!
This work is licensed under A Creative Commons Attribution-ShareAlike license.
I am no expert but user made Matlab codes are usually shared with the CC-BY-SA license meaning sharing, copying, adapting and transforming is allowed as long as the original authors are credited and the same licensing is kept.