reconstructing the original image from shuffled image

Hi all

I performed shuffling on image pixels like

shuffled_image=reshape(img(randperm(numel(img))),size(img));

In this way, I got the image whose pixels location are shuffled randomly.How can I get or reconstruct the original image (img) from the shuffled image.Every help is appreciated

Answer 1

[Matt J]

I'm assuming you saved the permutation indices, idx, as below

 idx=randperm(numel(img)); 
 shuffled_image=reshape(img(idx),size(img))

Then you can do,

 iidx(idx)=1:numel(img);

 recovered_image=reshape(shuffled_image(iidx),size(img))