diff --git a/hands/tracker/calib.py b/hands/tools/calib.py
similarity index 100%
rename from hands/tracker/calib.py
rename to hands/tools/calib.py
diff --git a/hands/tools/make_int8_calib.py b/hands/tools/make_int8_calib.py
deleted file mode 100644
index e4c943a..0000000
--- a/hands/tools/make_int8_calib.py
+++ /dev/null
@@ -1,79 +0,0 @@
-"""Calibration crops for quantizing the models to int8 (ncnn2table).
-
-Takes the frames of an fh-camprobe capture, cuts the crops the tracker would feed
-the models (CLAHE-equalized, as tracker/models.py prepares them), and writes them
-as PNGs plus a list per model:
-  palm: every search tile of every frame (a sample of them)
-  hand: the hands found in them, each also shifted, scaled and turned a little
-
-usage: python tools/make_int8_calib.py CAPTURE_DIR OUT_DIR
-"""
-import glob
-import os
-import random
-import sys
-
-import cv2
-import numpy as np
-
-sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'tracker'))
-import calib    # noqa: E402
-import hands    # noqa: E402
-import models   # noqa: E402
-
-NODES = {'video9': 'slam_left', 'video13': 'slam_right', 'video6': 'upper_left', 'video7': 'upper_right'}
-
-
-def save(path, patch):
-    cv2.imwrite(path, cv2.cvtColor(patch, cv2.COLOR_GRAY2BGR))
-
-
-def main():
-    cap, out = sys.argv[1], sys.argv[2]
-    random.seed(1)
-    cams = calib.load()
-    eng = models.Engine()
-    palm, hm = models.PalmDetector(), models.HandLandmarker()
-    tracker = hands.Tracker(cams, eng)
-    for d in ('palm', 'hand'):
-        os.makedirs(os.path.join(out, d), exist_ok=True)
-    palm_files, hand_files = [], []
-    for node, name in NODES.items():
-        tiles = [t for t in tracker.tiles if t.cam.name == name]
-        for f in sorted(glob.glob(os.path.join(cap, '*_%s.pgm' % node))):
-            g = cv2.imread(f, cv2.IMREAD_GRAYSCALE)
-            base = os.path.basename(f)[:-4]
-            prep = [palm.prepare(g, t.center, t.size, t.rotation) for t in tiles]
-            outs = eng.run([('palm', p) for p, _ in prep])
-            rois = []
-            for k, ((p, ctx), o) in enumerate(zip(prep, outs)):
-                if random.random() < 0.3:
-                    path = os.path.join(out, 'palm', '%s_t%02d.png' % (base, k))
-                    save(path, p)
-                    palm_files.append(path)
-                for d in palm.decode(o, ctx):
-                    r = d.roi()
-                    if all(np.linalg.norm(r[0] - q[0]) > 0.5 * r[1] for q in rois):
-                        rois.append(r)
-            for j, r in enumerate(rois):
-                p, ctx = hm.prepare(g, r)
-                if hm.decode(eng.run([('hand', p)])[0], ctx).presence < 0.5:
-                    continue
-                for v in range(5):
-                    c, s, rot = r
-                    if v:
-                        c = np.asarray(c) + np.random.uniform(-0.08, 0.08, 2) * s
-                        s = s * np.random.uniform(0.87, 1.15)
-                        rot = rot + np.radians(np.random.uniform(-20, 20))
-                    p, _ = hm.prepare(g, (c, s, rot))
-                    path = os.path.join(out, 'hand', '%s_h%d_%d.png' % (base, j, v))
-                    save(path, p)
-                    hand_files.append(path)
-    for name, files in (('palm', palm_files), ('hand', hand_files)):
-        with open(os.path.join(out, name + '.txt'), 'w') as fh:
-            fh.write('\n'.join(files) + '\n')
-        print(name, len(files), 'crops')
-
-
-if __name__ == '__main__':
-    main()
diff --git a/hands/tools/nettest_compare.py b/hands/tools/nettest_compare.py
deleted file mode 100644
index 0c1b7d5..0000000
--- a/hands/tools/nettest_compare.py
+++ /dev/null
@@ -1,90 +0,0 @@
-"""Compare trackd's C++ model code with tracker/models.py on recorded frames.
-
-For each frame, finds a crop with a palm (Python side), runs trackd/nettest on the same
-crop, and reports how far apart the palms, ROIs and landmarks are.
-
-usage: python tools/nettest_compare.py CAPTURE_DIR [--int8]
-"""
-import glob
-import os
-import subprocess
-import sys
-
-import cv2
-import numpy as np
-
-HERE = os.path.dirname(os.path.abspath(__file__))
-sys.path.insert(0, os.path.join(HERE, '..', 'tracker'))
-import calib    # noqa: E402
-import hands    # noqa: E402
-import models   # noqa: E402
-
-NODES = {'video9': 'slam_left', 'video13': 'slam_right', 'video6': 'upper_left', 'video7': 'upper_right'}
-NETTEST = os.path.join(HERE, '..', 'trackd', 'nettest')
-MODELS = os.path.join(HERE, '..', 'models', 'ncnn')
-
-
-def cpp(frame, tile, int8):
-    out = subprocess.run([NETTEST, MODELS, frame, str(tile.center[0]), str(tile.center[1]), str(tile.size),
-                          str(tile.rotation)] + (['--int8'] if int8 else []), capture_output=True, text=True).stdout
-    palms, hands_, ms = [], [], {}
-    for line in out.splitlines():
-        f = line.split()
-        if f[0] == 'palm':
-            palms.append((float(f[1]), np.array([float(f[6]), float(f[7])]), float(f[8]), float(f[9])))
-        elif f[0] == 'pts':
-            hands_.append(np.array(f[1:], float).reshape(21, 2))
-        elif f[0] == 'hand_ms':
-            ms.setdefault('hand', []).append(float(f[1]))
-            hands_presence = float(f[3])
-            ms.setdefault('presence', []).append(hands_presence)
-        elif f[0] == 'palm_ms':
-            ms.setdefault('palm', []).append(float(f[1]))
-    return palms, hands_, ms
-
-
-def main():
-    cap = sys.argv[1]
-    int8 = '--int8' in sys.argv
-    cams = calib.load()
-    eng = models.Engine()
-    palm, hm = models.PalmDetector(), models.HandLandmarker()
-    tracker = hands.Tracker(cams, eng)
-    d_roi, d_pts, n_py, n_cpp, pres = [], [], 0, 0, []
-    times = {'palm': [], 'hand': []}
-    for node, name in NODES.items():
-        tiles = [t for t in tracker.tiles if t.cam.name == name]
-        for f in sorted(glob.glob(os.path.join(cap, '*_%s.pgm' % node)))[::4]:
-            g = cv2.imread(f, cv2.IMREAD_GRAYSCALE)
-            for t in tiles:
-                p, ctx = palm.prepare(g, t.center, t.size, t.rotation)
-                dets = palm.decode(eng.run([('palm', p)])[0], ctx)
-                if not dets:
-                    continue
-                cp, ch, ms = cpp(f, t, int8)
-                for k in times:
-                    times[k] += ms.get(k, [])
-                n_py += len(dets)
-                n_cpp += len(cp)
-                for d in dets:
-                    r = d.roi()
-                    if not cp:
-                        continue
-                    j = int(np.argmin([np.linalg.norm(c[1] - r[0]) for c in cp]))
-                    d_roi.append(np.linalg.norm(cp[j][1] - r[0]) / r[1])
-                    pp, pctx = hm.prepare(g, r)
-                    lm = hm.decode(eng.run([('hand', pp)])[0], pctx)
-                    if lm.presence >= 0.5 and j < len(ch):
-                        d_pts.append(np.median(np.linalg.norm(ch[j] - lm.pts, axis=1)) / r[1])
-                        pres.append(abs(ms['presence'][j] - lm.presence))
-                break   # one palm tile per frame is enough
-    print('palms: python %d, c++ %d' % (n_py, n_cpp))
-    print('roi centre offset: median %.3f of the roi size (max %.3f)' % (np.median(d_roi), np.max(d_roi)))
-    if d_pts:
-        print('landmarks: median %.4f of the roi size (max %.4f), presence diff median %.3f' % (
-            np.median(d_pts), np.max(d_pts), np.median(pres)))
-    print('c++ time: palm %.1f ms, hand %.1f ms (median, one thread)' % (np.median(times['palm']), np.median(times['hand'])))
-
-
-if __name__ == '__main__':
-    main()
diff --git a/hands/trackd/Makefile b/hands/track/Makefile
similarity index 100%
rename from hands/trackd/Makefile
rename to hands/track/Makefile
diff --git a/hands/trackd/README.md b/hands/track/README.md
similarity index 100%
rename from hands/trackd/README.md
rename to hands/track/README.md
diff --git a/hands/trackd/calib.cpp b/hands/track/calib.cpp
similarity index 100%
rename from hands/trackd/calib.cpp
rename to hands/track/calib.cpp
diff --git a/hands/trackd/calib.h b/hands/track/calib.h
similarity index 100%
rename from hands/trackd/calib.h
rename to hands/track/calib.h
diff --git a/hands/trackd/geom.h b/hands/track/geom.h
similarity index 100%
rename from hands/trackd/geom.h
rename to hands/track/geom.h
diff --git a/hands/trackd/io.cpp b/hands/track/io.cpp
similarity index 100%
rename from hands/trackd/io.cpp
rename to hands/track/io.cpp
diff --git a/hands/trackd/io.h b/hands/track/io.h
similarity index 100%
rename from hands/trackd/io.h
rename to hands/track/io.h
diff --git a/hands/trackd/main.cpp b/hands/track/main.cpp
similarity index 100%
rename from hands/trackd/main.cpp
rename to hands/track/main.cpp
diff --git a/hands/trackd/nets.cpp b/hands/track/nets.cpp
similarity index 100%
rename from hands/trackd/nets.cpp
rename to hands/track/nets.cpp
diff --git a/hands/trackd/nets.h b/hands/track/nets.h
similarity index 100%
rename from hands/trackd/nets.h
rename to hands/track/nets.h
diff --git a/hands/trackd/pinch.cpp b/hands/track/pinch.cpp
similarity index 100%
rename from hands/trackd/pinch.cpp
rename to hands/track/pinch.cpp
diff --git a/hands/trackd/pinch.h b/hands/track/pinch.h
similarity index 100%
rename from hands/trackd/pinch.h
rename to hands/track/pinch.h
diff --git a/hands/trackd/record.cpp b/hands/track/record.cpp
similarity index 100%
rename from hands/trackd/record.cpp
rename to hands/track/record.cpp
diff --git a/hands/trackd/record.h b/hands/track/record.h
similarity index 100%
rename from hands/trackd/record.h
rename to hands/track/record.h
diff --git a/hands/trackd/replay.cpp b/hands/track/replay.cpp
similarity index 100%
rename from hands/trackd/replay.cpp
rename to hands/track/replay.cpp
diff --git a/hands/trackd/ringplay.cpp b/hands/track/ringplay.cpp
similarity index 100%
rename from hands/trackd/ringplay.cpp
rename to hands/track/ringplay.cpp
diff --git a/hands/trackd/tracker.cpp b/hands/track/tracker.cpp
similarity index 100%
rename from hands/trackd/tracker.cpp
rename to hands/track/tracker.cpp
diff --git a/hands/trackd/tracker.h b/hands/track/tracker.h
similarity index 100%
rename from hands/trackd/tracker.h
rename to hands/track/tracker.h
diff --git a/hands/trackd/nettest.cpp b/hands/trackd/nettest.cpp
deleted file mode 100644
index efd4cde..0000000
--- a/hands/trackd/nettest.cpp
+++ /dev/null
@@ -1,75 +0,0 @@
-// Check the C++ model code against tracker/models.py on a recorded frame:
-//   nettest MODELS_DIR FRAME.pgm cx cy size rotation [--int8]
-// Runs the palm detector on that crop, then the landmark model on each palm's ROI, and
-// prints what they found; tools/nettest_compare.py runs the Python side on the same input.
-#include "nets.h"
-
-#include <algorithm>
-#include <chrono>
-#include <cstdio>
-#include <cstring>
-#include <fstream>
-#include <string>
-#include <vector>
-
-static bool read_pgm(const char *path, std::vector<uint8_t> &px, int &w, int &h) {
-    std::ifstream f(path, std::ios::binary);
-    std::string magic;
-    int maxv;
-    if (!(f >> magic >> w >> h >> maxv) || magic != "P5") return false;
-    f.get();
-    px.resize(size_t(w) * h);
-    return bool(f.read(reinterpret_cast<char *>(px.data()), px.size()));
-}
-
-int main(int argc, char **argv) {
-    if (argc < 7) return std::fprintf(stderr, "usage: nettest MODELS FRAME.pgm cx cy size rotation [--int8] [--bench N]\n"), 1;
-    bool int8 = false;
-    int bench = 0;
-    for (int i = 7; i < argc; ++i) {
-        if (!std::strcmp(argv[i], "--int8")) int8 = true;
-        else if (!std::strcmp(argv[i], "--bench") && i + 1 < argc) bench = std::atoi(argv[++i]);
-    }
-    Nets nets;
-    std::string err;
-    if (!nets.load(argv[1], int8, err)) return std::fprintf(stderr, "%s\n", err.c_str()), 1;
-    std::vector<uint8_t> px;
-    int w, h;
-    if (!read_pgm(argv[2], px, w, h)) return std::fprintf(stderr, "can't read %s\n", argv[2]), 1;
-    const Image img{px.data(), w, h, w};
-    const V2 c{std::atof(argv[3]), std::atof(argv[4])};
-    if (bench > 0) {   // steady-state timing: warm up, then the median of N calls each
-        const Roi roi{c, std::atof(argv[5]), std::atof(argv[6])};
-        auto time = [&](auto fn) {
-            std::vector<double> t;
-            for (int i = 0; i < bench + 5; ++i) {
-                const auto t0 = std::chrono::steady_clock::now();
-                fn();
-                if (i >= 5) t.push_back(std::chrono::duration<double, std::milli>(std::chrono::steady_clock::now() - t0).count());
-            }
-            std::sort(t.begin(), t.end());
-            return t[t.size() / 2];
-        };
-        const double pm = time([&] { nets.palms(img, c, roi.size, roi.rotation); });
-        const double hm = time([&] { nets.landmarks(img, roi); });
-        std::printf("bench%s: palm %.2f ms, hand %.2f ms (median of %d, one thread)\n", int8 ? " int8" : "", pm, hm, bench);
-        return 0;
-    }
-    auto t0 = std::chrono::steady_clock::now();
-    const auto palms = nets.palms(img, c, std::atof(argv[5]), std::atof(argv[6]));
-    const double palm_ms = std::chrono::duration<double, std::milli>(std::chrono::steady_clock::now() - t0).count();
-    std::printf("palm_ms %.2f\n", palm_ms);
-    for (const Palm &p : palms) {
-        const Roi r = p.roi();
-        std::printf("palm %.3f  center %.1f %.1f  roi %.1f %.1f %.1f %.4f\n", p.score, p.center[0], p.center[1],
-                    r.center[0], r.center[1], r.size, r.rotation);
-        t0 = std::chrono::steady_clock::now();
-        const Landmarks lm = nets.landmarks(img, r);
-        const double ms = std::chrono::duration<double, std::milli>(std::chrono::steady_clock::now() - t0).count();
-        std::printf("hand_ms %.2f presence %.3f right %.3f\n", ms, lm.presence, lm.right);
-        std::printf("pts");
-        for (const V2 &q : lm.pts) std::printf(" %.1f %.1f", q[0], q[1]);
-        std::printf("\n");
-    }
-    return 0;
-}
diff --git a/hands/tracker/models.py b/hands/tracker/models.py
deleted file mode 100644
index a67af57..0000000
--- a/hands/tracker/models.py
+++ /dev/null
@@ -1,300 +0,0 @@
-"""MediaPipe's palm detector and hand landmark model on ncnn, CPU or Vulkan GPU.
-
-The models are the OpenCV Zoo ONNX ports, converted by tools/convert_models.py.
-Crops are square regions of a camera image given as (centre, size, rotation)
-in pixels and radians; rotation turns the crop's "up" towards the image
-direction (sin r, -cos r), as in MediaPipe. Both models take RGB in [0, 1];
-mono crops are replicated to three planes.
-
-Preparing crops and decoding outputs happen here; running the networks is an
-engine's job: Engine runs them in this process, Pool in worker processes
-(ncnn's Python binding holds the GIL while it infers, so threads don't help).
-"""
-import multiprocessing as mp
-import os
-from multiprocessing import connection, shared_memory
-
-import cv2
-import ncnn
-import numpy as np
-
-HERE = os.path.dirname(os.path.abspath(__file__))
-MODELS = os.path.join(HERE, '..', 'models', 'ncnn')
-
-# MediaPipe hand_landmarks_to_rect: the palm and finger bases used for the next ROI
-ROI_LANDMARKS = [0, 1, 2, 3, 5, 6, 9, 10, 13, 14, 17, 18]
-
-# per model: input size, output blobs and their sizes
-SPECS = {'palm': (192, [('out0', 2016 * 18), ('out1', 2016)]),
-         'hand': (224, [('out0', 63), ('out1', 1), ('out2', 1), ('out3', 63)])}
-
-
-def load_net(name, gpu, threads=1):
-    net = ncnn.Net()
-    net.opt.use_vulkan_compute = gpu
-    net.opt.num_threads = threads
-    net.opt.use_fp16_packed = net.opt.use_fp16_storage = net.opt.use_fp16_arithmetic = True
-    net.load_param(os.path.join(MODELS, name + '.ncnn.param'))
-    net.load_model(os.path.join(MODELS, name + '.ncnn.bin'))
-    return net
-
-
-def infer(net, kind, patch):
-    """Run one network on an 8-bit mono crop; returns its outputs, flattened."""
-    plane = patch.astype(np.float32) * (1.0 / 255.0)
-    x = np.ascontiguousarray(np.broadcast_to(plane, (3,) + plane.shape))
-    ex = net.create_extractor()
-    ex.input('in0', ncnn.Mat(x))
-    return [np.array(ex.extract(name)[1], np.float32).reshape(-1) for name, _ in SPECS[kind][1]]
-
-
-class Engine:
-    """Runs the networks in this process, one after another."""
-
-    def __init__(self, palm_gpu=False, hand_gpu=False):
-        self.nets = {'palm': load_net('palm', palm_gpu), 'hand': load_net('hand', hand_gpu)}
-
-    def run(self, jobs):
-        """jobs: [(kind, patch)] -> [outputs]"""
-        return [infer(self.nets[kind], kind, patch) for kind, patch in jobs]
-
-    def close(self):
-        pass
-
-
-def _worker(index, shm_name, conn, palm_gpu, hand_gpu, cpu):
-    if cpu is not None and cpu in os.sched_getaffinity(0):
-        os.sched_setaffinity(0, {cpu})
-    nets = {'palm': load_net('palm', palm_gpu), 'hand': load_net('hand', hand_gpu)}
-    shm = shared_memory.SharedMemory(name=shm_name)
-    base = index * Pool.STRIDE
-    while True:
-        msg = conn.recv()
-        if msg is None:
-            break
-        kind = msg
-        size = SPECS[kind][0]
-        patch = np.ndarray((size, size), np.uint8, shm.buf, base)
-        outs = infer(nets[kind], kind, patch)
-        off = base + Pool.IN_BYTES
-        for o in outs:
-            np.ndarray(o.shape, np.float32, shm.buf, off)[:] = o
-            off += o.nbytes
-        conn.send(True)
-    shm.close()
-
-
-class Pool:
-    """Runs the networks in worker processes pinned to CPUs, several crops at once."""
-    IN_BYTES = 224 * 224
-    OUT_BYTES = 4 * (2016 * 18 + 2016)
-    STRIDE = IN_BYTES + OUT_BYTES
-
-    # SteamOS on the Frame keeps user processes on CPUs 0-4 (5-7 carry pinned VR threads);
-    # 2-4 are the big cores among those
-    def __init__(self, workers=2, cpus=(2, 3, 4), palm_gpu=False, hand_gpu=False):
-        ctx = mp.get_context('spawn')
-        self.shm = shared_memory.SharedMemory(create=True, size=workers * self.STRIDE)
-        self.conns, self.procs = [], []
-        for i in range(workers):
-            a, b = ctx.Pipe()
-            cpu = cpus[i % len(cpus)] if cpus else None
-            p = ctx.Process(target=_worker, args=(i, self.shm.name, b, palm_gpu, hand_gpu, cpu), daemon=True)
-            p.start()
-            self.conns.append(a)
-            self.procs.append(p)
-
-    def run(self, jobs):
-        results = [None] * len(jobs)
-        pending = list(range(len(jobs)))
-        busy = {}                                          # conn -> job index
-        free = list(range(len(self.conns)))
-        while pending or busy:
-            while pending and free:
-                w = free.pop()
-                j = pending.pop(0)
-                kind, patch = jobs[j]
-                base = w * self.STRIDE
-                np.ndarray(patch.shape, np.uint8, self.shm.buf, base)[:] = patch
-                self.conns[w].send(kind)
-                busy[self.conns[w]] = (w, j)
-            for c in connection.wait(list(busy)):
-                c.recv()
-                w, j = busy.pop(c)
-                kind = jobs[j][0]
-                off = w * self.STRIDE + self.IN_BYTES
-                outs = []
-                for _, n in SPECS[kind][1]:
-                    outs.append(np.ndarray((n,), np.float32, self.shm.buf, off).copy())
-                    off += 4 * n
-                results[j] = outs
-                free.append(w)
-        return results
-
-    def pids(self):
-        return [p.pid for p in self.procs]
-
-    def close(self):
-        for c in self.conns:
-            try:
-                c.send(None)
-            except OSError:
-                pass
-        for p in self.procs:
-            p.join(1)
-        self.shm.close()
-        self.shm.unlink()
-
-
-def crop_matrix(center, size, rotation, out):
-    """2x3 affine taking crop pixels (0..out) to image pixels."""
-    c, s = np.cos(rotation), np.sin(rotation)
-    k = size / out
-    R = np.array([[c, -s], [s, c]]) * k
-    t = np.asarray(center, float) - R @ np.array([out / 2.0, out / 2.0])
-    return np.hstack([R, t[:, None]])
-
-
-# Local contrast per crop: the IR frames are dim and uneven (the upper cameras
-# especially). On the 2026-09-28 capture this found hands in more frames on every
-# camera than plain, stretched or gamma-corrected crops.
-CLAHE = cv2.createCLAHE(clipLimit=2.0, tileGridSize=(4, 4))
-
-
-def crop(gray, M, out):
-    """8-bit square crop of a mono image, with a crop->image matrix, contrast-equalized."""
-    patch = cv2.warpAffine(gray, M, (out, out), flags=cv2.INTER_LINEAR | cv2.WARP_INVERSE_MAP,
-                           borderMode=cv2.BORDER_CONSTANT, borderValue=0)
-    return CLAHE.apply(patch)
-
-
-def to_image(M, pts):
-    """Crop pixels (N,2) -> image pixels."""
-    return pts @ M[:, :2].T + M[:, 2]
-
-
-def normalize_angle(a):
-    return (a + np.pi) % (2 * np.pi) - np.pi
-
-
-def _anchors():
-    """SSD anchors of palm_detection_full: strides 8 (2 per cell) and 16 (6 per cell), 192x192."""
-    out = []
-    for stride, per_cell in ((8, 2), (16, 6)):
-        n = 192 // stride
-        for y in range(n):
-            for x in range(n):
-                out += [((x + 0.5) / n, (y + 0.5) / n)] * per_cell
-    return np.array(out, np.float32)
-
-
-class Detection:
-    """A palm in image pixels: box centre/size, 7 keypoints, score."""
-    __slots__ = ('center', 'size', 'keypoints', 'score')
-
-    def __init__(self, center, size, keypoints, score):
-        self.center, self.size, self.keypoints, self.score = center, size, keypoints, score
-
-    def roi(self):
-        """MediaPipe's hand ROI from a palm: wrist->middle-finger-base sets the rotation, then
-        shift 0.5 towards the fingers and scale the square box 2.6x."""
-        (x0, y0), (x1, y1) = self.keypoints[0], self.keypoints[2]
-        rot = normalize_angle(np.pi / 2 - np.arctan2(-(y1 - y0), x1 - x0))
-        w, h = (float(v) for v in self.size)
-        shift = np.array([-h * -0.5 * np.sin(rot), h * -0.5 * np.cos(rot)])
-        return np.asarray(self.center) + shift, max(w, h) * 2.6, rot
-
-
-class PalmDetector:
-    SIZE = 192
-
-    def __init__(self, min_score=0.5):
-        self.anchors = _anchors()
-        self.min_score = min_score
-
-    def prepare(self, gray, center, size, rotation=0.0):
-        M = crop_matrix(center, size, rotation, self.SIZE)
-        return crop(gray, M, self.SIZE), (M, size)
-
-    def decode(self, outputs, ctx):
-        """Palms found in one crop, in image pixels."""
-        M, size = ctx
-        raw = outputs[0].reshape(-1, 18)
-        logit = outputs[1]
-        keep = np.nonzero(logit > np.log(self.min_score / (1 - self.min_score)))[0]
-        if not len(keep):
-            return []
-        a = self.anchors[keep] * self.SIZE
-        r = raw[keep]
-        centers = r[:, 0:2] + a
-        sizes = r[:, 2:4]
-        kps = r[:, 4:18].reshape(-1, 7, 2) + a[:, None, :]
-        scores = 1 / (1 + np.exp(-np.clip(logit[keep], -100, 100)))
-        return [Detection(to_image(M, c[None])[0], s * size / self.SIZE, to_image(M, k), sc)
-                for c, s, k, sc in _weighted_nms(centers, sizes, scores, kps)]
-
-
-def _weighted_nms(centers, sizes, scores, kps, iou_thresh=0.3):
-    """MediaPipe's weighted NMS: overlapping boxes are averaged, weighted by score."""
-    order = np.argsort(-scores)
-    boxes = np.hstack([centers - sizes / 2, centers + sizes / 2])
-    area = np.prod(sizes, axis=1)
-    out = []
-    while len(order):
-        i = order[0]
-        xy0 = np.maximum(boxes[i, :2], boxes[order, :2])
-        xy1 = np.minimum(boxes[i, 2:], boxes[order, 2:])
-        inter = np.prod(np.clip(xy1 - xy0, 0, None), axis=1)
-        iou = inter / (area[i] + area[order] - inter + 1e-9)
-        group = order[iou > iou_thresh]
-        w = scores[group][:, None]
-        out.append(((centers[group] * w).sum(0) / w.sum(), (sizes[group] * w).sum(0) / w.sum(),
-                    (kps[group] * w[:, :, None]).sum(0) / w.sum(), float(scores[i])))
-        order = order[iou <= iou_thresh]
-    return out
-
-
-class Landmarks:
-    """21 hand landmarks in image pixels, plus MediaPipe's metric 'world' landmarks."""
-    __slots__ = ('pts', 'depth', 'world', 'presence', 'right', 'roi')
-
-    def __init__(self, pts, depth, world, presence, right, roi):
-        self.pts, self.depth, self.world, self.presence = pts, depth, world, presence
-        self.right, self.roi = right, roi
-
-    def next_roi(self):
-        return roi_from_points(self.pts)
-
-
-def roi_from_points(p):
-    """MediaPipe's hand_landmarks_to_rect: the crop to track a hand given its landmarks."""
-    x0, y0 = p[0]
-    x1, y1 = ((p[5] + p[13]) / 2 + p[9]) / 2
-    rot = normalize_angle(np.pi / 2 - np.arctan2(-(y1 - y0), x1 - x0))
-    sub = p[ROI_LANDMARKS]
-    center = (sub.min(0) + sub.max(0)) / 2
-    c, s = np.cos(-rot), np.sin(-rot)
-    q = (sub - center) @ np.array([[c, -s], [s, c]]).T
-    lo, hi = q.min(0), q.max(0)
-    mid = (lo + hi) / 2
-    c2, s2 = np.cos(rot), np.sin(rot)
-    center = center + np.array([mid[0] * c2 - mid[1] * s2, mid[0] * s2 + mid[1] * c2])
-    w, h = hi - lo
-    center = center + np.array([-h * -0.1 * s2, h * -0.1 * c2])
-    return center, max(w, h) * 2.0, rot
-
-
-class HandLandmarker:
-    SIZE = 224
-
-    def prepare(self, gray, roi):
-        center, size, rotation = roi
-        M = crop_matrix(center, size, rotation, self.SIZE)
-        return crop(gray, M, self.SIZE), (M, roi)
-
-    def decode(self, outputs, ctx):
-        M, roi = ctx
-        screen = outputs[0].reshape(21, 3)
-        pts = to_image(M, screen[:, :2])
-        depth = screen[:, 2] * roi[1] / self.SIZE                # relative depth, image pixels
-        return Landmarks(pts, depth, outputs[3].reshape(21, 3), float(outputs[1][0]), float(outputs[2][0]), roi)