SliceViewer error message

Why do I see this error message when clcking on the "Slice Viewer" on the REST opening page

 image_toolbox not valid
> In rest_sliceviewer>InitControls at 1053
  In rest_sliceviewer at 74
  In rest_sliceviewer at 38
  In reho_gui>btnSliceViewer_Callback at 1110
  In gui_mainfcn at 96
  In reho_gui at 35

 Your matlab does not have image toolbox installed so you can not use sliceviewer.
If you wanna use it, you have to install imaging procesing toolbox.