Transforms

Inverse Discrete Wavelet Transformation

The assignment was to write a program that calculates the Inverse DWT using Daubechies fourth-order coefficients, of a vector of length 2^12, with a 1 in the 5th and 30th places and zeros elsewhere. In the program below, you can actually enter a vector of indexes where you want the 1's to be placed. An inverse FFT of such signals would reveal sinusoids or sumed sinusoids. Here are some examples of the behavior of the IDWT and its base function: the wavelet function.

Signals with 1's at the following places are demonstrated :

- 5
- 5, 30
- 5, 10, 15, 20, 30, 35, 40, 45, 50
- 5, 25, 125, 625
- 4, 40, 400, 4000

Here is the Matlab code :