i am trying to implement probality density function on an image but i can not understand how to calculate data, mu and sigma.here is my code is it right to take data as pixl value

 k = imread('2.jpg');
 img2=rgb2gray(k);

sigma =?;
mu=?
pd = makedist('Normal',mu,sigma);
data = img2(I,j)
y = pdf(pd,data);
figure,
plot(data,y,'LineWidth',2)

Answer 1

[Walter Roberson]

mu = mean2(img2);
sigma = std2(img2);

[bushra mughal]

how to calculate data?it should be scaler

[Walter Roberson]

Why should it be a scalar? You are expecting the output of pdf(pd,data) to be something you can plot(), which suggests you do not want a scalar output. pdf(pd,data) will return an array the same size as data, so pdf() does not need it to be a scalar.

[Walter Roberson]

My theory is that you are trying to fit a Normal Distribution to a histogram of the gray levels. http://www.mathworks.com/help/stats/histfit.html but also http://www.mathworks.com/matlabcentral/answers/44962#answer_55073

[bushra mughal]

actualy I am trying to calculate probability density function for img2