obtaining magnitude of histogram plot

I have plot the histogram of an image using imhist() function. I want to obtain the magnitude of the histogram plot. imhist() returns 2 arguments : counts and x.

img=imread('C:\Users\Divya\Desktop\1_2_1.bmp');
img1=rgb2gray(img);
[counts x]=imhist(img1,20000);

counts and x both are 20000*1 array. It does not provide information about the whole image

Any pointers on how i can obtain this data?

Answer 1

[Kanishk]

Hello Divya,

The histogram does describe the whole image, just not spatially. You can compute the magnitude (total pixel count per bin):

total_pixels = sum(counts);

If by "magnitude" you mean the peak value:

max_count = max(counts);

If you want to normalize the Histogram to get probability instead of raw counts:

normalized_counts = counts / sum(counts);

If you want to view Basic Image Summary: (e.g., min, max, mean intensity):

stats.min_val = min(img1(:));
stats.max_val = max(img1(:));
stats.mean_val = mean(img1(:));
stats.std_val = std(double(img1(:)));

Hope this helps!!