[HELP] RGB histogram of an object

Hey guys!! I'm new on MATLAB and I was trying to build the RGB histogram of the object that appears in an image. To do that I have the image of the background and the image of the same background with the object in the foreground.

I tried this code but it doesn't work :( Any ideas?

A = imread('background.jpg');
B = imread('image.jpg');
d = double(B)- double(A);
R = d(:, :, 1);
G = d(:, :, 2);
B = d(:, :, 3);
Color = d/255;
surf(R,G,B,Color);

Thank youuu!! =)

Answer 1

[Image Analyst]

Don't use surf(). Use imhist() to get the counts, and plot() or bar() or area() to plot the histogram. See attached demo.

[Image Analyst]

amelia's "Answer" moved here because it's really a comment to me and not an answer to her original question:

I'm using surf because I want the 3D histogram, not 3 histograms 2D like you did :(

[Image Analyst]

Then you need to do

hist3D(R+1, G+1, B+1) = 
hist3D(R+1, G+1, B+1) + 1

In other words, you need to build up the true 256 by 256 by 256 3D histogram. surf() does not build histograms, neither does hist2d().

Answer 2

[Image Analyst]

I do have this attached demo that calculates the 3D histogram. See attached file below the image it creates.

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If you want a better one that includes a lot more powerful visualizations, see Color Inspector 3D. It's an imageJ plugin but you can use it from MATLAB.