How to combine different histograms ?

I have several different histograms and I want to take as a result a final histogram. I am looking for a way to combine the different histograms and manage to make it one.

[jasche]

how do you want to combine these images ? on what context ?

Answer 1

[Image Analyst]

As long as the bins cover the same ranges, you can simply add them. If they don't, then you'll have to align the ranges some how, which might mean taking the histograms again with histc and making sure all the bins are in the same places.

[Jenny]

Every histogram shows the frequency of white pixels of a photo on the vertical axis and the area (mm^2) on the horizontal axis, so the bins do not cover the same ranges because it depends on the maximum white pixel area of every photo.

[Image Analyst]

So it's a particle size distribution. No problem - you can still specify the size range for each bin with histc(). It doesn't matter if some bins are bigger or smaller than what that particular image has because it will just create those bins as empty. But this is what you need to do to add the histograms together.

[Jenny]

Thanks for your help ! :)

[sweta arya]

i=imread('138.jpg'); i=rgb2gray(i); size(i) binranges = 0:255; [bincounts] = histc(x,binranges); figure bar(binranges,bincounts,'histc') giving error in this code, Error using barV6 (line 13) Inputs must be 2-D.

Error in bar (line 47) h = barV6(cax, args{:});

[sweta arya]

i=imread('138.jpg');
i=rgb2gray(i);
size(i)
binranges = 0:255;
[bincounts] = histc(x,binranges);
figure
bar(binranges,bincounts,'histc')
giving error in this code,
Error using barV6 (line 13)
Inputs must be 2-D.

Error in bar (line 47)
        h = barV6(cax, args{:});

Hello, what is the code for addition of different histograms

[Image Analyst]

% Let's compute and display the histogram.
[pixelCount, grayLevels] = imhist(grayImage);
bar(grayLevels, pixelCount); % Plot it as a bar chart.
grid on;
title('Histogram of gray scale version of image', 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Gray Level', 'FontSize', fontSize);
ylabel('Pixel Count', 'FontSize', fontSize);
xlim([0 grayLevels(end)]); % Scale x axis manually.