Starting with MATLAB R2021b, the syntax for the “lwt2”function has been updated. Previously, the "lifewave"object was used, but it has now been replaced by the "liftingScheme"object. To obtain CA as a double-type matrix of size M/2 by N/2, where M and N are the dimensions of “img”, the “liftingScheme”object needs to be passed to the "lwt2"function along with its level.
Kindly refer to the code below:
img=imread('image.bmp');
img=im2double(img);
lScheme = liftingScheme("Wavelet","haar");
[CA, CH, CV, CD] = lwt2(img,LiftingScheme=lScheme,Level=1);
disp(CA);
For more information on "liftingScheme" object and “lwt2” function, refer to below documentation. https://www.mathworks.com/help/wavelet/ref/liftingscheme.html#:~:text=lscheme%20%3D%20liftingScheme(%27Wavelet%27%2Cwname) https://www.mathworks.cn/help/wavelet/ref/lwt2.html#:~:text=lwt2%20input%20syntax%20has%20changed
Hope this clarifies the issue!
