This is what happens when I installed SIVP: atomsInstall(“SIVP”)
Scanning repository http://atoms.scilab.org/5.5 … Done

ans =

!SIVP 0.5.3.2-1 allusers SCI\contrib\SIVP.5.3.2-1 I !

included in case there is something wrong with this output. But then when I try imread command I get the undefined variable: imread.

-->atomsInstall('sivp')
atomsInstallList: The package sivp is not available.
 !--error 10000 

at line      51 of function atomsError called by :  
at line      76 of function atomsInstallList called by :  
at line     217 of function atomsInstall called by :  
atomsInstall('sivp')


-->atomsInstall("sivp")
atomsDownload: The following file hasn't been downloaded:
	 - URL            : 'http://atoms.scilab.org/TOOLBOXES/32/linux.gz'
	 - Local location : '/tmp/SD_21631_/.atoms/TOOLBOXES.gz'
 !--error 10000 

at line     200 of function atomsDownload called by :  
at line      63 of function atomsGetTOOLBOXES called by :  
at line     213 of function atomsInstall called by :  
atomsInstall("sivp")

I then tries installing it manually by downloading the package and following the instructions. That too did now have the toolbox installed (I cannot find it in the GUI). It just doesn’t seem to get me to the point where I can use im* functions.

 Package opencv was not found in the pkg-config search path.   
  error(gettext("OpenCV (version >= 1.0.0) is needed for compiling SIVP."));
                                                                            !--error 10000 
OpenCV (version >= 1.0.0) is needed for compiling SIVP.
at line      72 of exec file called by :    

at line      10 of function tbx_builder_gateway_lang called by :  
tbx_builder_gateway_lang(languages, sci_gateway_dir);
at line       6 of exec file called by :    

at line       8 of function devtools_run_builder called by :  
at line       6 of function tbx_builder_gateway called by :  
tbx_builder_gateway(toolbox_dir);
at line      35 of exec file called by :    
exec('builder.sce')

FYI, imshow & imread are provided by a Scilab extension
atomsInstall(‘sivp’) should do it.

There are also some work to see Scilab into Fedora:
https://bugzilla.redhat.com/show_bug.cgi?id=472639

but it still needs to have JoGL into Fedora before:
https://bugzilla.redhat.com/show_bug.cgi?id=572515