manualhist.m

冈萨雷斯的经典教材数字图像处理的matlab版源代码

function p = manualhist
%MANUALHIST Generates a two-mode histogram interactively.
%   P = MANUALHIST generates a two-mode histogram using
%   TWOMODEGAUSS(m1, sig1, m2, sig2, A1, A2, k).  m1 and m2 are the
%   means of the two modes and must be in the range [0,1].  sig1 and
%   sig2 are the standard deviations of the two modes.  A1 and A2 are 
%   amplitude values, and k is an offset value that raised the
%   "floor" of histogram.  The number of elements in the histogram
%   vector P is 256 and sum(P) is normalized to 1.  MANUALHIST
%   repeatedly prompts for the parameters and plots the resulting
%   histogram until the user types an 'x' to quit, and then it returns
%   the last histogram computed.
%
%   A good set of starting values is: (0.15, 0.05, 0.75, 0.05, 1,
%   0.07, 0.002).  

%   Copyright 2002-2004 R. C. Gonzalez, R. E. Woods, & S. L. Eddins
%   Digital Image Processing Using MATLAB, Prentice-Hall, 2004
%   $Revision: 1.7 $  $Date: 2003/10/13 00:49:57 $

% Initialize.
repeats = true;
quitnow = 'x';

% Compute a default histogram in case the user quits before
% estimating at least one histogram. 
p = twomodegauss(0.15, 0.05, 0.75, 0.05, 1, 0.07, 0.002);

% Cycle until an x is input.
while repeats  
   s = input('Enter m1, sig1, m2, sig2, A1, A2, k OR x to quit:','s');
   if s == quitnow 
      break
   end
   
   % Convert the input string to a vector of numerical values and
   % verify the number of inputs.
   v = str2num(s);
   if numel(v) ~= 7
      disp('Incorrect number of inputs')
      continue
   end
   
   p = twomodegauss(v(1), v(2), v(3), v(4), v(5), v(6), v(7));
   % Start a new figure and scale the axes. Specifying only xlim
   % leaves ylim on auto. 
   figure, plot(p)
   xlim([0 255])
end