Resizing a 3D image without using imresize3

I do not have the image processing toolbox on my MatLab 2016b so I cannot use the imresize3() function. Is there other ways to resize an image of (x,y,z) to (a,b,c)?

Answer 1

[Matt J]

This FEX file is a generalization of imresize to any array dimension, and doesn't use any toolboxes.

https://www.mathworks.com/matlabcentral/fileexchange/64516-imresizen-resize-an-n-dimensional-array?s_tid=srchtitle

However, it only handles grayscale images, and doesn't do any anti-aliasing. All new values are based purely on interpolation.

Answer 2

[Walter Roberson]

ifftn( fftn(YourImage), [a, b, c] )

[Bogdan Dzyubak]

Transforming the image this way forward and back produces tons of ringing. There's also a warping artifact (perhaps fftshift is needed). With imresize, the forward and back transform gives a blurrier original image which is more desirable.

Answer 3

[Ahmadi Anis]

I have an MRI image with this size (140,192,192), so this script will insert my image in the center of an output matrix with this size (X,Y,Z) by adding zero

this script works ;)

clear;
clc;
matrice= niftiread('C:\Users\anis8\Desktop\1.nii');

X=256;
Y=256;
Z=256;

matrice=[zeros(floor(X-size(matrice,1))/2,size(matrice,2),size(matrice,3));...
    matrice;...
    zeros(floor(X-size(matrice,1))/2,size(matrice,2),size(matrice,3))];%%reglage de x

matrice=[zeros(X,floor(Y-size(matrice,2))/2,size(matrice,3)),...
    matrice...
    ,zeros(X,floor(Y-size(matrice,2))/2,size(matrice,3))];%%reglage de y

matrice=cat(3,zeros(X,Y,floor(Z-size(matrice,3))/2),...
    matrice...
   ,zeros(X,Y,floor(Z-size(matrice,3))/2));%%reglage de z

[Radhika Gupta]

Hey!

is there any way to resize .nii file and save in same format istead of a matrix?

Answer 4

[Shivam]

You can use "for" loop for each 2D image, and than use imresize():

Im=zeros(N,N,N);

I=zeros(n,n,n);

for i=1:N

I(:,:,i)=imresize(squeeze(Im(:,:,i)),[n n]);

end;