View full-text article in PMC Diagnostics (Basel). 2021 Dec 23;12(1):22. doi: 10.3390/diagnostics12010022 Search in PMC Search in PubMed View in NLM Catalog Add to search Copyright and License information © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). PMC Copyright notice Algorithm 1. Computing the IS-OS frontier. 1:function compute7thLayer(I,pars) 2: bwImg=Seg2(I,100,pars.Enh,pars.Smooth) 3: img=bwImg⨂image 4: gradImg=getGradientMap(img, 5: darkToBright,params) 6: [B7,Y]=getSegBoundary(gradImg) 7: return[B7,Y] 8:end function