[07d29c]: imhist.m Maximize Restore History

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imhist.m    73 lines (62 with data), 2.1 kB

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## Copyright (C) 1999,2000 Kai Habel
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
## -*- texinfo -*-
## @deftypefn {Function File} {} imhist (@var{I},@var{n})
## @deftypefnx {Function File} {} imhist (@var{I})
## @deftypefnx {Function File} {} imhist (@var{X},@var{cmap})
## @deftypefnx {Function File} {[@var{n,x}] = } imhist (...)
## Shows the histogram of an image using hist
## @end deftypefn
## @seealso{hist}
## Author: Kai Habel <kai.habel@gmx.de>
## July 2000 : Paul Kienzle code simplification for hist() call.
function [varargout] = imhist (I, b)
if (nargin < 1 || nargin > 2)
usage("imhist(image,n)");
endif
b_is_colormap = 0;
if (nargin == 2)
if (is_matrix (b))
b_is_colormap = (columns (b) == 3);
endif
endif
if (b_is_colormap)
## assuming I is an indexed image
## b is colormap
max_idx = max (max (I));
bins = rows (b);
if (max_idx > bins)
warning ("largest index exceedes length of colormap");
endif
else
## assuming I is an intensity image
## b is number of bins
if (nargin == 1)
bins = 256;
else
bins = b;
endif
## scale image to range [0,1]
I = mat2gray (I);
endif
if (nargout == 2)
[nn,xx] = hist (I(:), bins);
vr_val_cnt = 1; varargout{vr_val_cnt++} = nn;
varargout{vr_val_cnt++} = xx;
else
hist (I(:), bins);
endif
endfunction