- added alpha matte clip

git-svn-id: http://moon:8086/svn/matlab/trunk@149 801c6759-fa7c-4059-a304-17956f83a07c

chromakey/clip_black.m

@@ -0,0 +1,32 @@
+## Copyright (C) 2020 Jens
+## 
+## 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 3 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, see
+## <https://www.gnu.org/licenses/>.
+
+## -*- texinfo -*- 
+## @deftypefn {} {@var{retval} =} clip_black (@var{input1}, @var{input2})
+##
+## @seealso{}
+## @end deftypefn
+
+## Author: Jens <jens@orion>
+## Created: 2020-10-04
+
+function y = clip_black (x, thresh, k)
+ind = find (x >= thresh);
+
+y = x/k;
+y(ind) = thresh/k + (x(ind)-thresh)*(1+thresh);
+
+endfunction