Distribution of pixel intensity in percentage plot

0
votes

I am trying to plot the pixel intensity in percentage of a gray scale image. I have done the preprocessing part of scaling and equalization of the gray image.

I know he histogram plot gives the pixel intensity distribution along the Y axis but i want that in percentage.

Any help is appreciated.

The code i used is here

  clc;
    close all;
    clear all;
    I=imread('sand5.jpg');
    j=rgb2gray(I);
    figure,imshow(j);
    J=scale_image(j,1);
    figure,imshow(J);
    K=histeq(J);
    figure,imshow(K);

I need the plot for Pixel intensity distribution in percentage VS pixel intensity values(0-255) along x axis for the gray scale image.

1
matlabimage-processingplot

1 Answers

2
votes

You need to compute the histogram

nn = hist( K(:), 0:255 ); % histogram for 0..255 bins

Now nn counts the number of pixels at each bin. To get the percentage you only need to divide by the total number of pixels (numel(K)) and multiply by 100.

figure;
bar( 0:255, nn*numel(K)/100 );
title('pixel intensity distribution (%)');
xlabel('intensity level');
ylabel('%');