Does wavedec2 and waverec2 support complex valued array inputs?

2 次查看（过去 30 天）
Johnathan Le
Johnathan Le 2023-4-19
编辑： Johnathan Le 2023-4-19
I'm trying to use the wavedec2 and waverec2 functions on a complex valued image and I'm finding that the reconstructed image is not match the input image. Using dwt2 and idwt2 seems to work with the same complex valued array however.
%% works
[cA,cH,cV,cD] = dwt2(Image,'haar');
test = idwt2(cA,cH,cV,cD,'haar');
norm(Image - test,2) %% returns 1.27e-12
%% does not work
[c,s] = wavedec2(Image,1,'haar');
test = waverec2(c,s,'haar');
norm(Image - test,2) %% returns 6.79e+03

请先登录，再回答此问题。

回答（1 个）

Walter Roberson
Walter Roberson 2023-4-19
The documentation for wavedec2() does not say that the input, X, must be real-valued.
However, the output vector is defined as being real-valued, and is defined as having a particular size, and those conditions together imply that you cannot reconstruct a complex matrix
  1 个评论
Johnathan Le
Johnathan Le 2023-4-19
编辑：Johnathan Le 2023-4-19
Thank you for replying to the question. The documentation does say that the output vector is real-valued but I do get complex-valued wavelet coefficients when inputing a complex-valued matrix. Furthermore, it doesn't make sense to me why dwt2 and idwt2 work for complex-valued inputs while wavedec2 and waverec2 do not work when specifying wavedec2 and waverec2 to do a single level wavelet transform.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Image Analysis 的更多信息

标签

产品


版本

R2019b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by