imresize function in SliceViewer

Hello,
I got the following error when trying to load the overlay a T map generated with the 2 sample T test function.
Do you have any suggestions on how to fix it? I am using Matlab 2011b with the Image Processing and Statistics toolboxes.
Thank you.

Undefined function 'imresize' for input arguments of type 'double'.

Error in rest_sliceviewer>AddOverlay (line 2924)
theOverlay =imresize(theOverlay, floor([(size(theOverlay, 1)-1)*Xvol+1,
(size(theOverlay, 2)-1)*Xvol+1]*theMagnifyCoefficient));

Error in rest_sliceviewer>SetView_Orthogonal (line 1471)
theSagittalImg =AddOverlay('Sagittal' ,AConfig, theSagittalImg,theMagnifyCoefficient);

Error in rest_sliceviewer>SetImage (line 1387)
Result =SetView_Orthogonal(AConfig);

Error in rest_sliceviewer (line 453)
REST_SliceViewer_Cfg.Config(theCardinal)
=SetImage(REST_SliceViewer_Cfg.Config(theCardinal));

Error in rest_sliceviewer (line 527)
rest_sliceviewer('ChangeOverlay', AFigHandle);

Error while evaluating uicontrol Callback