convert image wave by a lookup wave

function convertByLookUpWave(wave2d,lookupWave[,reverseColors])
    wave wave2d         // the wave to be transformed
    wave lookupWave     // the lookup wave that is used
    variable reverseColors  // pass reverseColors=1 if the original image is shown with a reversed color table
 
    if(wavedims(wave2d)!=2)
        print "Works only with 2-dimensional waves!"
        return 0
    endif
    if(wavemin(lookupWave) < 0 || wavemax(lookupWave)>1)
        print "Values of lookup wave must be in the range [0,1]!"
        return 0
    endif
    duplicate/free lookupWave lw,dw
    setscale/i x,0,1,dw
    wavestats/q wave2d
    if(reverseColors==1)
        setscale/i x,V_max,V_min,lw
        dw=V_max+x*(V_min-V_max)
    else
        setscale/i x,V_min,V_max,lw
        dw=V_min+x*(V_max-V_min)
    endif
    wave2d = dw(lw(wave2d[p][q]))
end