Color Image Histogram

Display a histogram showing the color balance of an image.

Description

RGBHIST displays a histogram of the overall color balance of an image.

Use the 'RGB' mode to get a quick sense of which colors are present in particular highlight, shadow, and midtone regions. The 'LAB' mode is more useful for determining the actual color balance of an image, but it is slower.

This function supports UINT8, UINT16, INT8, INT16, and DOUBLE images without colormaps.

• Required Products: Image Processing Toolbox
• MATLAB release: MATLAB 6.5 (R13)

[valla dafrel]

 

[feng Yang]

asome

[reza saffari]

 

[reza saffari]

 

[visesh Jeetoo]

It does seem to give the following error" In an assignment A(I) = B, the number of elements in B and I must be the same" when trying to find the histogram of a 256x256 colour image

[Lahmar karim]

??? In an assignment A(I) = B, the number of elements in B and
 I must be the same.

[Arjan Gijsenij]

Error: In an assignment A(I) = B, the number of elements in B and
I must be the same.

[hanif mohammadi]

 

[Lei sheng]

 

[Maria Gorlatova]

Does not work. Error: In an assignment A(I) = B, the number of elements in B and
I must be the same.

Must be something version-dependent

[eman mehrabadi]

log

[Jong-Cheon park]

 

[mohammed Alnafea]

 

[Mark Hayworth]

This doesn't work in R14/2006a (and I doubt it did in his version either), or at least it needs fixing. It produces a stem plot, not a plot like his screenshot shows. And the stem plot is only for the B channel because he forgot to issue a HOLD command after the line h(1) = stem(1:256, rHist); so the green blows away the red plot, and the blue blows away the green plot so that only the blue stem plot is there after all is said and done. Finally, there is nothing in this macro about different color spaces, RGB or LAB, no radio buttons to select between them, in fact, no user interface at all.

[gabrielle tuijthof]

 

[muthu krishnan]

good

[Kevin Ostheimer]

??? Invalid handle object.

Error in ==> rgbhist at 19
set(h, 'marker', 'none')

[angry sam]

doesn't work

[Syed Murtaza Hussain]

Good one

[ayman nassar]

it gives the following error
??? Invalid handle object.

Error in ==> rgbhist at 19
set(h, 'marker', 'none'

[dolly jain]

??? Invalid handle object.

Error in ==> rgbhist at 19

[KAsper HAnsen]

Doesn't work.

[Mourad Oussalah]

 

[Bruce Banner]

Not working

[Divya Seelan]

 

[Joao Silva]

 

[kubilay i?ci]

hello

[hanan yaseen]

please sir can you explain the steps of the program to me? is it an intersection of the histograms of all the colors in the image or what exactly?
i hope you can respond me or any one who understand this program can explain it to me
i will be very thankful

[santosh saraf]

Sir,

when u convert rgb2hsi we get an hsi component image. Sir, can i treat the h matrix as an image

Please reply

[keshamoni Divya]

 

[esraa ahmed]

 

[papu champu]

good

[mustafa omar]

no comment

[Sakthi Kandan]

Hello
      In the above program how to get an image,is there any special syntax has to be used to get an image.
     I used the syntax
            I=imread('lena.jpg') ;
But it's giving me error.
  Is there any special syntax to get the RGB image.

[muhammad ashraf]

Respected Sir,
             I am having error with your code.following is the error
??? Invalid handle object.

Error in ==> rgbhist at 19
set(h, 'marker', 'none')

Sir please tell how can i make histogram of color imag in matlab.
                    thanks

[muhammad ashraf]

Respected Sir, ho to solve tis problem?
it gives the following error
??? Invalid handle object.

Error in ==> rgbhist at 19
set(h, 'marker', 'none'
 please help me how can i make color imag histogram?
                    thanks

[Muhammad Nawaz]

Excellent

[Tomasz]

stem(1:256, rHist,'r');hold on
stem(1:256 + 1/3, gHist,'g');
stem(1:256 + 2/3, bHist,'b');
hold off

[Ronny Meza]

Very nice

[Jess]

My modification on Jeff's initial code (including comment by Tomasz). Now input image & histogram derived are display in same figure window.

function rgbhist(I)
%RGBHIST Histogram of RGB values.

if (size(I, 3) ~= 3)
    error('rgbhist:numberOfSamples', 'Input image must be RGB.')
end

nBins = 256;

rHist = imhist(I(:,:,1), nBins);
gHist = imhist(I(:,:,2), nBins);
bHist = imhist(I(:,:,3), nBins);

%hFig = figure;

figure
subplot(1,2,1);imshow(I)
subplot(1,2,2);

h(1) = stem(1:256, rHist); hold on
h(2) = stem(1:256 + 1/3, gHist);
h(3) = stem(1:256 + 2/3, bHist);
hold off

set(h, 'marker', 'none')
set(h(1), 'color', [1 0 0])
set(h(2), 'color', [0 1 0])
set(h(3), 'color', [0 0 1])
axis square

[Dongni Zhang]

It works well with the modification of Jeff in 29 Apr 2011. Thank you!