Laplacian Image Pyramid Reconstruction

Hi all

I am generating a Laplacian pyramid based on Gaussian Pyramid.

img=imread('lena.bmp'); 512*512 size
pyr=cell(1,4);
pyr{1}=img;
pyr=impyramid(img,'reduce');
for p=2:4
pyr{p}=impyramid(pyr{p-1},'reduce'); %% this makes image hierarchy of 4 layers
end
%laplacian pyramid generation
lap=pyr{1}-impyramid(pyr{2},'expand');

gettting error to generate first laplacian image layer, because expansion of second gaussian layer size is less than the first layer of gaussian pyramid. How can I achieve that?

Thanks in advance

Answer 1

[Zhuofan Zheng]

https://blogs.mathworks.com/steve/2019/04/16/multiresolution-pyramids-part-3-laplacian-pyramids/

this blog could help you.

your problem is caused by the downsample by 2.