Wavelet Transform: 2D Scalogram

Wavelet

Signal

Decomposition levels

Signal frequency

Detail threshold

Noise level

Readouts

Reconstruction MSE

-

Non-zero coefficients

-

Compression ratio

-

Energy in approximation

-

Perfect-recon. check (no threshold)

-

Samples

-

Analysis: a = (x * lowpass) down 2, d = (x * highpass) down 2, recursively on a. Haar h=[1,1]/sqrt2; db4 h=(1+-sqrt3, 3+-sqrt3)/(4 sqrt2). Detail coefficients below the threshold are zeroed (hard or soft) before inverse transform.