myhistimage(in)

function [out] = myhistimage(in)
% Copyright 2009 The MathWorks, Inc.

persistent bitmapHandle;

if ishandle(bitmapHandle)
    figure(bitmapHandle);
    set(bitmapHandle, 'Visible', 'off');
    cla;
else
    bitmapHandle = figure('Visible', 'off');
    set(bitmapHandle, 'Color', [1 1 1]);
    set(bitmapHandle, 'PaperPositionMode', 'auto');
end;

a = get(bitmapHandle, 'Position');
s = size(in);
a(3) = s(1);
a(4) = s(2);

[X, count] = imhist(in);
stem(count, X, '-', '.');

axis tight;
set(bitmapHandle, 'Position', a);
pixels = hardcopy(bitmapHandle,'-dOpenGL','-r0');

% Size of the bitmap produced by hardcopy may be larger than that 
% specified by the figure width & height.
% Also transpose to get the correct bitmap orientation for .ToVector
for i = 3:-1:1, 
    pixs(:,:,i) = pixels(1:s(2),1:s(1),i)'; %#ok
end;
out = rgb2gray(pixs);