X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=utilities_ESRF%2Fimpad.m;fp=utilities_ESRF%2Fimpad.m;h=d8151f99a00bc66888f24afce8d3e02c8f0fb690;hp=0000000000000000000000000000000000000000;hb=99b9890c11d31f9ae22dd481873e01c708175073;hpb=d0401c49b6b7511cfdaa0534b78bd3c5b2b0637a

diff --git a/utilities_ESRF/impad.m b/utilities_ESRF/impad.m
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+## Copyright (C) 2000 Teemu Ikonen
+##
+## 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, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} impad(@var{A}, @var{xpad}, @var{ypad}, [@var{padding}, [@var{const}]])
+## Pad (augment) a matrix for application of image processing algorithms.
+##
+## Pads the input image @var{A} with @var{xpad}(1) elements from left, 
+## @var{xpad}(2), elements from right, @var{ypad}(1) elements from above 
+## and @var{ypad}(2) elements from below.
+## Values of padding elements are determined from the optional arguments
+## @var{padding} and @var{const}. @var{padding} is one of
+##
+## @table @samp
+## @item "zeros"     
+## pad with zeros (default)
+##
+## @item "ones"      
+## pad with ones
+##
+## @item "constant"  
+## pad with a value obtained from the optional fifth argument const
+##
+## @item "symmetric" 
+## pad with values obtained from @var{A} so that the padded image mirrors 
+## @var{A} starting from edges of @var{A}
+## 
+## @item "reflect"   
+## same as symmetric, but the edge rows and columns are not used in the padding
+##
+## @item "replicate" 
+## pad with values obtained from A so that the padded image 
+## repeates itself in two dimensions
+## 
+## @end table
+## @end deftypefn
+
+## Author: Teemu Ikonen <tpikonen@pcu.helsinki.fi>
+## Created: 5.5.2000
+## Keywords: padding image processing
+
+## A nice test matrix for padding:
+## A = 10*[1:5]' * ones(1,5) + ones(5,1)*[1:5]
+
+function retim = impad(im, xpad, ypad, padding = "zeros", const = 1)
+  ## Input checking
+  if (!ismatrix(im) || ndims(im) < 2 || ndims(im) > 3)
+    error("impad: first input argument must be an image");
+  endif
+  if (isscalar(xpad) && xpad >= 0)
+    xpad(2) = xpad;
+  elseif (!isreal(xpad) || numel(xpad) != 2 || any(xpad < 0))
+    error("impad: xpad must be a positive scalar or 2-vector");
+  endif
+  if (isscalar(ypad) && ypad >= 0)
+    ypad(2) = ypad;
+  elseif (!isreal(ypad) || numel(ypad) != 2 || any(ypad < 0))
+    error("impad: ypad must be a positive scalar or 2-vector");
+  endif
+  if (!isscalar(const))
+    error("impad: fifth input argument must be a scalar");
+  endif
+
+  origx = size(im,2);
+  origy = size(im,1);
+  retx = origx + xpad(1) + xpad(2);
+  rety = origy + ypad(1) + ypad(2);
+  cl = class(im);
+
+  for iter = size(im,3):-1:1
+    A = im(:,:,iter);
+    switch (lower(padding))
+      case "zeros"
+        retval = zeros(rety, retx, cl);
+        retval(ypad(1)+1 : ypad(1)+origy, xpad(1)+1 : xpad(1)+origx) = A;
+      case "ones"
+        retval = ones(rety, retx, cl);
+        retval(ypad(1)+1 : ypad(1)+origy, xpad(1)+1 : xpad(1)+origx) = A;
+      case "constant"
+        retval = const.*ones(rety, retx, cl);
+        retval(ypad(1)+1 : ypad(1)+origy, xpad(1)+1 : xpad(1)+origx) = A;
+      case "replicate"
+        y1 = origy-ypad(1)+1;
+        x1 = origx-xpad(1)+1;    
+        if (y1 < 1 || x1 < 1 || ypad(2) > origy || xpad(2) > origx)
+          error("impad: too large padding for this padding type");
+        else
+          yrange1 = y1:origy;
+          yrange2 = 1:ypad(2);
+          xrange1 = x1:origx;
+          xrange2 = 1:xpad(2);
+          retval = [ A(yrange1, xrange1), A(yrange1, :), A(yrange1, xrange2);
+                     A(:, xrange1),       A,             A(:, xrange2);
+                     A(yrange2, xrange1), A(yrange2, :), A(yrange2, xrange2) ];
+        endif                        
+      case "symmetric"
+        y2 = origy-ypad(2)+1;
+        x2 = origx-xpad(2)+1;
+        if (ypad(1) > origy || xpad(1) > origx || y2 < 1 || x2 < 1)
+          error("impad: too large padding for this padding type");
+        else
+          yrange1 = 1 : ypad(1);
+          yrange2 = y2 : origy;
+          xrange1 = 1 : xpad(1);
+          xrange2 = x2 : origx;
+          retval = [ fliplr(flipud(A(yrange1, xrange1))), flipud(A(yrange1, :)), fliplr(flipud(A(yrange1, xrange2)));
+                     fliplr(A(:, xrange1)), A, fliplr(A(:, xrange2));
+                     fliplr(flipud(A(yrange2, xrange1))), flipud(A(yrange2, :)), fliplr(flipud(A(yrange2, xrange2))) ];
+        endif      
+      case "reflect"
+        y2 = origy-ypad(2);
+        x2 = origx-xpad(2);
+        if (ypad(1)+1 > origy || xpad(1)+1 > origx || y2 < 1 || x2 < 1)
+          error("impad: too large padding for this padding type");
+        else
+          yrange1 = 2 : ypad(1)+1;
+          yrange2 = y2 : origy-1;
+          xrange1 = 2 : xpad(1)+1;
+          xrange2 = x2 : origx-1;
+          retval = [ fliplr(flipud(A(yrange1, xrange1))), flipud(A(yrange1, :)), fliplr(flipud(A(yrange1, xrange2)));
+                     fliplr(A(:, xrange1)), A, fliplr(A(:, xrange2));
+                     fliplr(flipud(A(yrange2, xrange1))), flipud(A(yrange2, :)), fliplr(flipud(A(yrange2, xrange2))) ];
+        endif
+      otherwise   
+        error("impad: unknown padding type");
+    endswitch
+    
+    retim(:,:,iter) = retval;
+  endfor      
+endfunction