Failed to add uniform noise to the image

Hi Everyone, I am trying to add uniform noise using the following syntax,

image = ones([512,512])*128;

A = .1;

B = .2;

matrix_uniform = A + (B-A)*rand(size(image));

noisy_image = imnoise(uint8(image),'localvar',matrix_uniform);

K = wiener2(noisy_image,[5 5]);

figure, subplot(1,3,1),imshow(noisy_image), subplot(1,3,2), imshow(K),

subplot(1,3,1), imhist(noisy_image)

But I am unable to get uniform shape in the histogram. Can anyone tell me what wrong I am doing?

Answer 1

[Iman Ansari]

Hi. You don't need imnoise:

round(128+0.2)=128

with 0.1 and 0.2 like you didn't add any noise. Uniform noise with zero mean:

image = ones([512,512])*128;
A = -30;
B = 30;
matrix_uniform = A + (B-A)*rand(size(image));
noisy_image = image + matrix_uniform;

figure,
subplot(1,2,1)
imshow(noisy_image./255), 
subplot(1,2,2)
imhist(uint8(noisy_image))