Wavelet transform using dwt3 in MATLAB

Question

I have a project to transform an image using dwt.
I successfully done it using function dwt2, and now I try to use function dwt3 by changes some code from the function dwt2 (add more subband: 8 subbands). Unfortunately, an error comes out, which said "Too many output arguments".

My question is, what is the right way to write MATLAB code for dwt3? Is it not same as dwt2, just add more subbands?

Answer 1

Just by looking at the official documentation for dwt2 and dwt3, I see that dtw3 has only 1 output variable, whereas dtw2 has 4.

I assume you just replaced the string dtw2 in your code to dwt3, without paying attention to the amount of allowed output variables. So there you go, that's where the error "too many output variables" comes from...

If dwt3 only returns the transformed vector, cut the number of output variables to 1, and I'm sure the error will away:

Y = dwt3(X, 'db2');

Here I transformed X using dwt3 with the Daubechies 2-tap wavelet, and stored the result in Y.

P.S
You need to show more code if you want more productive, helpful answers...