Watershedsegmentationissuitableforproducingclosedregioncontourandprovidinganaccuratelocalizationofobjectboundary.However,itisusuallypronetoover-segmentationduetothenoiseandirregulardetailswithintheimage.Forthepurposeofreducingover-segmentationwhilepreservingthelocationofobjectcontours,thewatershedsegmentationbasedonmorphologicalgradientreliefmodificationusingvariantstructuringelement(SE)isproposed.Firstly,morphologicalgradientreliefisdecomposedintomulti-levelaccordingtothegradientvalues.Secondly,morphologicalclosingactionusingvariantSEisemployedtoeachlevelimage,wherethelowgradientlevelsetsusethelargeSE,whilethehighgradientlevelsetsusethesmallone.Finally,themodifiedgradientimageisrecomposedbythesuperpositionoftheclosedlevelsets,andwatershedtransformtothemodifiedgradientimageisdonetoimplementthefinalsegmentation.Experimentalresultsshowthatthismethodcaneffectivelyreducetheover-segmentationandpreservethelocationoftheobjectcontours.
