Question

Sum of the wavelet coefficients is positive or negative

Answer 1

Explanation:

Wavelet Denoising✍✍✍✍✍✍

Wavelet coefficients which are small in value are typically noise and you can "shrink" those coefficients or remove them without affecting the signal or image quality.

After you threshold the coefficients, you reconstruct the data using the inverse wavelet transform.

Answer 2

Answer:

Negative wavelet coefficients are obtained, when negative excursions of both the signal and wavelet are convolved in CWT operation. Similarly you get positive wavelet coefficients, when positive excursions of both the signal and wavelet are convolved. This facilitates to easily understand the changes in physical phenomena responsible for generating the signal, as a function of time or space. The boundaries separating the positive and negative wavelet coefficients in wavelet scalogram signify the zones of changes in physical phenomena. So, negative coefficients are also as important as positive ones, but the difference is only that they are 'negative'.