nx_coco_oks.nx

nx_coco_oks.nx -- the REAL COCO industry metric OKS (Object Keypoint Similarity), replacing our self-validating PCK-vs-our-own-teacher. OKS = Sum_i exp(-d_i^2 / (2 s^2 k_i^2)) * [v_i>0] / Sum_i [v_i>0], where d_i = pred-GT distance, s^2 = the person's segment AREA (from the COCO annotation), k_i = 2*sigma_i, sigma_i the OFFICIAL COCO per-keypoint constants. This is what AP@[.5:.95] thresholds -> the number the field grades pose by. Needs GROUND-TRUTH annotations (area + GT keypoints) to be meaningful -- it is NOT computable against our own port. license_tier: ORIGINAL