X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fimage-1.0.15%2Fimtranslate.m;fp=octave_packages%2Fimage-1.0.15%2Fimtranslate.m;h=675e56cb6f806382690662111983596f6051fb4a;hp=0000000000000000000000000000000000000000;hb=c880e8788dfc484bf23ce13fa2787f2c6bca4863;hpb=1705066eceaaea976f010f669ce8e972f3734b05

diff --git a/octave_packages/image-1.0.15/imtranslate.m b/octave_packages/image-1.0.15/imtranslate.m
new file mode 100644
index 0000000..675e56c
--- /dev/null
+++ b/octave_packages/image-1.0.15/imtranslate.m
@@ -0,0 +1,73 @@
+## Copyright (C) 2002 Jeff Orchard
+##
+## 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} {@var{Y}} = imtranslate (@var{M}, @var{x}, @var{y} [, @var{bbox}])
+## Translate a 2D image by (x,y) using Fourier interpolation.
+##
+## @var{M} is a matrix, and is translated to the right by @var{X} pixels
+## and translated up by @var{Y} pixels.
+##
+## @var{bbox} can be either 'crop' or 'wrap' (default).
+##
+## @end deftypefn
+
+## Author: Jeff Orchard <jjo@cs.sfu.ca>
+## bug fix: Eugeniy Mikhailov in 2009 (removing fftshift and ifftshift they do no good)
+
+function Y = imtranslate(X, a, b, bbox_in)
+
+	bbox = "wrap";
+	if ( nargin > 3 )
+		bbox = bbox_in;
+	endif
+
+	if ( strcmp(bbox, "crop")==1 )
+
+		xpad = [0,0];
+		if (a>0)
+			xpad = [0,ceil(a)];
+		elseif (a<0)
+			xpad = [-ceil(a),0];
+		endif
+
+		ypad = [0,0];
+		if (b>0)
+			ypad = [ceil(b),0];
+		elseif (b<0)
+			ypad = [0,-ceil(b)];
+		endif
+
+		X = impad(X, xpad, ypad, 'zeros');
+	endif
+
+
+	[dimy, dimx] = size(X);
+	x = fft2(X);
+	px = exp(-2*pi*i*a*(0:dimx-1)/dimx);
+	py = exp(-2*pi*i*b*(0:dimy-1)/dimy)'; 	% actually to correspond to index notation 'b' should be
+						% replaced with '-b'
+						% but I do not want to brake previous version compatibility
+						% note: it also must be done in the cropping iand padding code
+	P = py * px;
+	y = x .* P;
+	Y = real(ifft2(y)); 	% fft return complex number
+				% for integer shifts imaginary part  is 0 
+				% so real takes care of transfer from complex number to real
+
+	if ( strcmp(bbox, "crop")==1 )
+		Y = Y(  ypad(1)+1:dimy-ypad(2) , xpad(1)+1:dimx-xpad(2));
+	endif
+endfunction