How do I draw the scatterplot of an RGB image?

[darova]

Can you elaborate? I don't understand the question

[Parveiz Lone]

I need to draw pixel intensity distribution of two neighbouring pixels at horizontal , vertical and digonal directions

[darova]

Any ideas?

[Image Analyst]

Yes, did you see my answer down below in the Answers section?

[darova]

Yes, sorry. I'm just not a native english speaker

[Image Analyst]

Parveiz, please explain in words what the two axes of your scatterplots represent.

1. What does n,m on the x axis represent?
2. What does n+1, m+1 on the y axis represent?
3. Why do both of your scatterplots have the same x and y labels? They are not the same scatterplots yet they have the same axis labels. Why?

Answer 1

[KALYAN ACHARJYA]

image_test=rgb2gray(imread('2.png')); % Change the image
[rows colm]=size(image_test);
original_data=zeros(1,56512);
diag_data=zeros(1,56512);
hor_data=zeros(1,56512);
ver_data=zeros(1,56512);
l=1;
%ignoring boundary elements
for i=2:rows-1
    for j=2:colm-1
        original_data(l)=image_test(i,j);
        diag_data(l)=image_test(i+1,j+1);
        hor_data(l)=image_test(i,j+1);
        ver_data(l)=image_test(i+1,j);
        l=l+1;
    end
end
subplot(131),plot( original_data,diag_data,'b.','linewidth',2);
xlabel('n,m'), ylabel('n+1,m+1'),title('Diagonal');
subplot(132),plot( original_data,diag_data,'b.','linewidth',2);
xlabel('n,m'), ylabel('n,m+1'),title('Horizontal');
subplot(133),plot( original_data,diag_data,'b.','linewidth',2);
xlabel('n,m'), ylabel('n+1,m'),title('Vertical');

[KALYAN ACHARJYA]

subplot(131),scatter( original_data,diag_data,'b.','linewidth',2);
%..............^^ would be same result, do in all 3 lines

[Parveiz Lone]

What 56512 indicate ? Or is it m*n size of image

[KALYAN ACHARJYA]

Possible total iterations or

row*colm - ignoring boundary pixels

Answer 2

[Image Analyst]

You need to use colorcloud(). It does a 3-D scatterplot of the RGB gamut.