How can I implement a Homomorphic filter in Matlab?

Question

I have taken the source code from here and tried to modify it to fit my need. But, the filter is not working as expected. I am not being able to find the issue in my code.

What is the issue with my modified code?

Expected Output

Actual Output

---

Source Code

main.m

clc
close all
clear all
d=10;
order=2;
im=double(imread('tun.png'));
subplot(121)
imshow(im./255);
[r, c]=size(im);
j = homofil(im,d,order);
imshow(j);

homofil.m

function output = homofil(I, d, n)
    I = double(I);

    H = butter_hp_kernel(I, d, n); 

    alphaL = .0999;
    aplhaH = 1.01;
    H = ((aplhaH-alphaL).*H)+alphaL;
    H = 1-H;

    im_l = log2(1+I);
    im_f = fft2(im_l);
    im_nf = H.*im_f;
    im_n = abs(ifft2(im_nf));
    output = exp(im_n);

butter_hp_kernel.m

function k = butter_hp_kernel(I, Dh, n) 
    Height = size(I,1); 
    Width = size(I,2); 

    [u, v] = meshgrid( ...
                    -floor(Width/2) :floor(Width-1)/2, ...
                    -floor(Height/2): floor(Height-1)/2 ...
                 ); 

    k = butter_hp_f(u, v, Dh, n);

function f = butter_hp_f(u, v, Dh, n)
    uv = u.^2+v.^2;
    Duv = sqrt(uv);
    frac = Dh./Duv;
    %denom = frac.^(2*n);
    A=0.414; denom = A.*(frac.^(2*n));    
    f = 1./(1.+denom);

---

Input Image

Answer 1

I had a more detailed explanation and stackoverflow went into maintenance and I couldn't post. So here's the one-line explanation.

Your j is the wrong range: [1, 1.08] so it shows white.
Do imshow(j, []) or convert j with mat2gray