What are wavelet levels?
This slider lets you decide how many detail levels the image will be decomposed into. You can choose any level between 4 and 9 (the 10th level, called Extra, appears automatically when you select level 9). The higher the number, the more processing time and memory will be required.
How do wavelets work?
A wavelet is a wave-like oscillation with an amplitude that begins at zero, increases or decreases, and then returns to zero one or more times. Wavelets are termed a "brief oscillation". A taxonomy of wavelets has been established, based on the number and direction of its pulses.
Which wavelet to choose?
An orthogonal wavelet, such as a Symlet or Daubechies wavelet, is a good choice for denoising signals. A biorthogonal wavelet can also be good for image processing. Biorthogonal wavelet filters have linear phase which is very critical for image processing.