pw = cal.pixelWidth
    if bVerbose:
        print(pw)
    if u == scaUm:
        if (pw <= 0.02):
            barW =  0.10  # bar width, microns
        elif (pw < 0.06):
            barW =  1.0   # bar width, microns
        else:
            barW =  10.0

    strBar = "width=%g height=%g font=%g color=%s location=[%s] bold" % (barW, barH, barF, barC, barL)
    # a hack to get the scale bars to work reliably
    foo = orig.duplicate()
    if (bSetGrayLevels == True):
        bd = orig.getBitDepth()
        if(bd==16):
            IJ.setMinAndMax(foo, gLo, gHi)    
    IJ.run(foo, "RGB Color", "")
    IJ.run(foo, "Add Scale Bar", strBar)
    foo.close()

    if (bSetGrayLevels == True):
        bd = orig.getBitDepth()
        if(bd==16):
            IJ.setMinAndMax(orig, gLo, gHi)
    else:
        sArgSat = "saturated=%.2f" % gSatFac
        IJ.run(orig, "Enhance Contrast", sArgSat)

    if(bDoTiltCorrect == True):