在matlab中计算直方图的期望和方差

Question

I want to compute the standard deviation and expected value of the given histogram.

Which matlab function will help me to do that?

My code:

I = imread('download.bmp');
imshow(I);title('Input Image');

imhist(I(:));title('Histogram of input image');

Answer 1

Not quite sure, whether I am getting your question properly. By expected value of the histogram, do you mean the mean intensity value of the image, so basically which intensity you are most likely to draw if you draw a random pixel?

This you could simply get by doing

m_wholeImage = mean(I(:));
s_wholeImage = std(double(I(:)));

s_wholeImage then gives you the standard deviation of all pixel values.

Answer 2

I would suggest this reference :

Gonzalez., R., Eddins., S. and Woods, R. (2009). Digital image processing using MATLAB. 2nd ed. Gatesmark Publishing, pp.644-654.

It mentions code for quantifying texture in an image, and that involves finding mean and standard deviation of the image histogram.

I found the code online :

http://fourier.eng.hmc.edu/e161/dipum/statxture.m

http://fourier.eng.hmc.edu/e161/dipum/statmoments.m