Hazy image equation implementation.

I have an hazy image equation. When I am try to implement that equattion I only get a black image only.

This is my equation. How can I implement this equation in matlab correctly.Please help me.

[KALYAN ACHARJYA]

Can you define A and t(x)?

Answer 1

[Thiago Henrique Gomes Lobato]

Can it be possible that you are just making a wrong conversion of your image data? With the code below I show an example of what would be a right and wrong conversion, besides this the code seems to work :

rng default
% Image and parameters
I = imread('cameraman.tif');
A = 0.5;
t = randn(size(I)); % t must have same dimensions as I
t = abs(t)/max(abs(t(:)))*0.7+0.3; % Normalize so no division by zero value possible
Hazy = @(I,A,t) (I-A*(1-t))./t; % Define your function, make sure it is element-wise

% Wrong Image conversion 
J1 = Hazy(double(I),A,t);

% Right image conversion
J2 = Hazy(im2double(I),A,t);

figure,
subplot(1,3,1)
imshow(J1)
subplot(1,3,2)
imshow(I)
subplot(1,3,3)
imshow(J2)

If you have a RGB image, make sure to apply it individually to every third dimension of your image matrix.

[Silpa K]

I used this, but I didn't get the correct output.

clc
clear
rng default
% Image and parameters
M= imread('img4.tiff');
I=double(M)
tot = sum(double(I(:)))
[K L] = size(I);
A=((1./(K*L))*tot)
SD=std2(I)
t1= (I./A)
t2= SD * t1
t= 1-t2;
t = randn(size(I)); % t must have same dimensions as I
t = abs(t)/max(abs(t(:)))*0.7+0.3; % Normalize so no division by zero value possible
Hazy = @(I,A,t) (I-A*(1-t))./t; % Define your function, make sure it is element-wise
% Wrong Image conversion
J1 = Hazy(double(I),A,t);
% Right image conversion
J2 = Hazy(im2double(I),A,t);
figure,
subplot(1,3,1)
imshow(J1,[])
subplot(1,3,2)
imshow(I,[])
subplot(1,3,3)
imshow(J2,[])

I am getting the image like this

[Thiago Henrique Gomes Lobato]

Can you maybe post your image? I run the code you gave using your t variable (the one that I defined was random just to exemplify it, it shouldn't be in your code) in the image and got those results, which seems reasonable:

[Silpa K]

Sir, the following link is provided my dataset.

I use the '7.1.09' this image from that.

The link is http://sipi.usc.edu/database/database.php?volume=misc&image=24#top

[Thiago Henrique Gomes Lobato]

The problem was that you was defining your filter as a function of the image values before converting to normalize doubles, so your t had some crazy negative values and produced the black image. The following code works:

clc
clear
rng default
% Image and parameters
M= imread('5.3.02.tiff');
I=im2double(M);
tot = sum(double(I(:)));
[K L] = size(I);
A=((1./(K*L))*tot);
SD=std2(I);
t1= (I./A);
t2= SD * t1;
t= 1-t2;
Hazy = @(I,A,t) (I-A*(1-t))./t; % Define your function, make sure it is element-wise

J1 = Hazy(I,A,t);

figure,
subplot(1,2,1)
imshow(J1,[])
subplot(1,2,2)
imshow(I,[])

Answer 2

[Image Analyst]

Chances are that your image is floating point and you forgot to put [] in imshow.

imshow(yourImage, []);