nx_blob.nx

nx_blob.nx -- largest connected skin region (R2-refine). Fixes localization: a global skin bbox spans the whole frame when skin is everywhere; the LARGEST CONNECTED COMPONENT is the actual subject. Builds a GRIDxGRID occupancy map (cell = skin if >=50% of its pixels are skin), labels it with two-pass union-find connected-component labeling (4-connectivity), and returns the biggest component's cell count + grid bounding box + box area. Coarse grid (not per-pixel CCL) keeps it cheap and robust: a person is a coarse blob; scattered skin-coloured speckle never forms a big component. out[]: [0]=blob_cells [1..4]=grid bbox minx,miny,maxx,maxy [5]=bbox_cells [6]=total_occupied_cells [7]=grid genealogy_id: connected_component_labeling_union_find (record-hint) lineage_id: occupancy_grid + two_pass_ccl + largest_component license_tier: ORIGINAL