Skip to main content
. 2011 Jul 15;4:7. doi: 10.3389/fneng.2011.00007

Table 2.

Haar mother wavelet coefficients for SWT.

Level 1 (j = 1) Level 2 (j = 2) Level 3 (j = 3)
High-pass filter, Gj g1[0] = −0.7071067812 g2[0] = −0.7071067812 g3[0] = −0.7071067812
g1[1] = 0.7071067812 g2[1] = 0 g3[1] = 0
g2[2] = 0.7071067812 g3[2] = 0
g2[3] = 0 g3[3] = 0
g3[4] = 0.7071067812
g3[5] = 0
g3[6] = 0
g3[7] = 0
Low-pass filter, Hj h1[0] = 0.7071067812 h2[0] = 0.7071067812 h3[0] = 0.7071067812
h1[1] = 0.7071067812 h2[1] = 0 h3[1] = 0
h2[2] = 0.7071067812 h3[2] = 0
h2[3] = 0 h3[3] = 0
h3[4] = 0.7071067812
h3[5] = 0
h3[6] = 0
h3[7] = 0

The main drawback of SWT algorithm is its computational expensiveness. We will address this issue quantitatively later in this paper. More information about wavelet analysis can be found in Meyer and Ryan (1993), Coifman and Donoho (1995), Pesquet et al. (1996), Niervergelt (2001), and Jensen and La Cour-Harbo (2001).