fix(photos): preserve tapered tips and dark live edge (#73 #74)

Lower the axial body threshold while retaining fringe rejection, minimize length-only tip inset, and make sheet sensitivity curves testable and conservative at zero.

frontend/src/mask/sheetKeep.test.ts

@@ -0,0 +1,59 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { blackKeep, greenKeep } from './sheetKeep.ts';
+
+// --- Black sheet sensitivity (#74) ---
+
+test('blackKeep: s=0 keeps dark live-edge wood (lum ~25–50), removes near-black sheet (#74)', () => {
+  // Near-black sheet (lum ≈ 5)
+  assert.equal(blackKeep(5, 5, 5, 0), false, 'near-black sheet removed at s=0');
+  assert.equal(blackKeep(0, 0, 0, 0), false, 'pure black sheet removed at s=0');
+  // Dark wood / bark / live edge
+  assert.equal(blackKeep(25, 22, 18, 0), true, 'lum~22 dark wood kept at s=0');
+  assert.equal(blackKeep(40, 35, 30, 0), true, 'lum~35 dark wood kept at s=0');
+  assert.equal(blackKeep(50, 45, 40, 0), true, 'lum~46 wood kept at s=0');
+  // Mid wood always kept
+  assert.equal(blackKeep(120, 90, 60, 0), true, 'mid wood kept at s=0');
+});
+
+test('blackKeep: s=100 removes more than s=0; curve monotonic (#74)', () => {
+  // Dark-ish pixel that sits between floors: sheet at high s, wood at low s
+  const darkish = { r: 80, g: 70, b: 60 }; // lum ≈ 72
+  assert.equal(blackKeep(darkish.r, darkish.g, darkish.b, 0), true, 'lum~72 kept at s=0');
+  assert.equal(blackKeep(darkish.r, darkish.g, darkish.b, 100), false, 'lum~72 sheet at s=100');
+
+  // Near-black always sheet
+  assert.equal(blackKeep(2, 2, 2, 0), false);
+  assert.equal(blackKeep(2, 2, 2, 100), false);
+
+  // Bright wood always kept
+  assert.equal(blackKeep(200, 160, 100, 0), true);
+  assert.equal(blackKeep(200, 160, 100, 100), true);
+
+  // Monotonic: once removed, stays removed as s increases
+  const probe = { r: 60, g: 55, b: 50 }; // lum ≈ 56
+  let prevKeep = true;
+  for (const s of [0, 25, 50, 75, 100]) {
+    const keep = blackKeep(probe.r, probe.g, probe.b, s);
+    if (!prevKeep) assert.equal(keep, false, `once sheet at lower s, stay sheet at s=${s}`);
+    prevKeep = keep;
+  }
+  // s=100 must remove more pixels than s=0 for this mid-dark band
+  assert.equal(blackKeep(probe.r, probe.g, probe.b, 0), true);
+  assert.equal(blackKeep(probe.r, probe.g, probe.b, 100), false);
+});
+
+test('greenKeep: s=0 does not eat mild wood greens; s=100 widens sheet match (#74)', () => {
+  // Neutral wood
+  assert.equal(greenKeep(140, 110, 80, 0), true);
+  assert.equal(greenKeep(140, 110, 80, 100), true);
+  // Mild green cast on wood (g - max(r,b) ≈ 5) — must keep at s=0
+  assert.equal(greenKeep(100, 105, 90, 0), true, 'mild green cast kept at s=0');
+  // Strong sheet green
+  assert.equal(greenKeep(40, 180, 50, 0), false, 'strong green sheet removed at s=0');
+  assert.equal(greenKeep(40, 180, 50, 100), false);
+  // Borderline: g-max ≈ 20 — may become sheet at high s
+  const border = { r: 80, g: 100, b: 70 }; // delta = 20
+  assert.equal(greenKeep(border.r, border.g, border.b, 0), true, 'delta20 kept at s=0');
+  assert.equal(greenKeep(border.r, border.g, border.b, 100), false, 'delta20 sheet at s=100');
+});

frontend/src/mask/sheetKeep.ts

@@ -0,0 +1,36 @@
+/**
+ * Sheet-vs-slab keep predicates used by the mask worker.
+ * Extracted so unit tests can cover sensitivity curves without the worker.
+ */
+
+/** Keep slab pixels on a green sheet. Higher s widens the green-sheet match. */
+export function greenKeep(r: number, g: number, b: number, s: number): boolean {
+  const t = Math.max(0, Math.min(100, s)) / 100;
+  // s=0 removes only strongly green sheet; increasing sensitivity widens the match.
+  const isSheet = g - Math.max(r, b) > 45 - 35 * t;
+  return !isSheet;
+}
+
+/**
+ * Keep slab pixels on a black sheet.
+ * At s=0 only near-black sheet (very low lum) is removed so dark live-edge /
+ * bark (lum ~25–50) stays. The match widens monotonically toward s=100 (#74).
+ */
+export function blackKeep(r: number, g: number, b: number, s: number): boolean {
+  const t = Math.max(0, Math.min(100, s)) / 100;
+  const lum = 0.2126 * r + 0.7152 * g + 0.0722 * b;
+  // Old floor 40 ate dark wood at minimum sensitivity. Floor 10 isolates near-black.
+  const isSheet = lum < 10 + 140 * t;
+  return !isSheet;
+}
+
+export function autoPickSheet(
+  samples: { r: number; g: number; b: number }[],
+): 'green' | 'black' {
+  let gr = 0, gl = 0;
+  for (const p of samples) {
+    if (p.g - Math.max(p.r, p.b) > 20) gr++;
+    if (0.2126 * p.r + 0.7152 * p.g + 0.0722 * p.b < 70) gl++;
+  }
+  return gl >= gr ? 'black' : 'green';
+}

frontend/src/png/overlay.test.ts

@@ -6,6 +6,7 @@ import {
   axisRightUnit,
   buildOverlayPlan,
   inventorySourceMap,
+  BODY_WIDTH_FRAC,
   type OverlayPlan,
 } from './overlay.ts';
 import { orientedRect, minAreaRect } from '../geometry/rect.ts';
@@ -403,7 +404,7 @@ test('buildOverlayPlan: length axial span = robust tip stations; no AABB oversho
     widths.push({ bin, width });
     if (width > maxWidth) maxWidth = width;
   }
-  const thresh = Math.max(4, maxWidth * 0.32);
+  const thresh = Math.max(4, maxWidth * BODY_WIDTH_FRAC);
   widths.sort((a, b) => a.bin - b.bin);
   let tipLo = widths[0].bin, tipHi = widths[widths.length - 1].bin;
   for (const { bin, width } of widths) {
@@ -423,8 +424,8 @@ test('buildOverlayPlan: length axial span = robust tip stations; no AABB oversho
   const lenAxial = Math.hypot(plan.length.b[0] - plan.length.a[0], plan.length.b[1] - plan.length.a[1]);
   // Axial edge-inset (#71) shortens span slightly vs tip stations
   assert.ok(
-    lenAxial <= tipAxial + 2 && lenAxial >= tipAxial - 24,
+    lenAxial <= tipAxial + 2 && lenAxial >= tipAxial - 8,
-    `length span ${lenAxial.toFixed(1)} must match width-aware tip span ${tipAxial.toFixed(1)} (allow inset)`,
+    `length span ${lenAxial.toFixed(1)} must match width-aware tip span ${tipAxial.toFixed(1)} (allow small axial inset only; #73)`,
   );
 
   // Axial stations of length ends = tip stations (pure axis-right offset does not change along-u).
@@ -623,7 +624,7 @@ test('buildOverlayPlan: length a→b || approved (ux,uy); width left→right ||
     wbins.push({ bin, width });
     if (width > maxW) maxW = width;
   }
-  const thresh = Math.max(4, maxW * 0.32);
+  const thresh = Math.max(4, maxW * BODY_WIDTH_FRAC);
   wbins.sort((a, b) => a.bin - b.bin);
   let tipLo = wbins[0].bin, tipHi = wbins[wbins.length - 1].bin;
   for (const { bin, width } of wbins) {
@@ -695,12 +696,13 @@ function fringeTipFixture() {
   for (let y = 120; y <= 440; y++) {
     for (let x = 90; x <= 190; x++) bitset[y * W + x] = 1;
   }
-  // Dense fringe whiskers (narrower than body) past top/bottom — denser than 0.2%
+  // Dense fringe whiskers (~10% of body width) past tips — denser than 0.2%.
+  // Must stay below BODY_WIDTH_FRAC (#73 ~0.15) so width-aware tips exclude them.
   for (let y = 95; y < 120; y++) {
-    for (let x = 130; x <= 150; x++) bitset[y * W + x] = 1;
+    for (let x = 135; x <= 145; x++) bitset[y * W + x] = 1;
   }
   for (let y = 441; y <= 465; y++) {
-    for (let x = 130; x <= 150; x++) bitset[y * W + x] = 1;
+    for (let x = 135; x <= 145; x++) bitset[y * W + x] = 1;
   }
   // Approved axis ~vertical (slight tilt)
   const ang = (8 * Math.PI) / 180;
@@ -957,3 +959,161 @@ test('buildOverlayPlan: labels inside inventory PNG; length off wood; smaller fo
     );
   }
 });
+
+
+// --- Tapered live-edge tips must not be dropped (#73) ---
+
+/**
+ * Live-edge taper: body max width ~100px; tips taper to ~20% of max (~20px).
+ * Old BODY_WIDTH_FRAC=0.32 dropped tip bins; length dim under-reached wood ends.
+ */
+function taperedTipFixture() {
+  const W = 240, H = 500;
+  const bitset = new Uint8Array(W * H);
+  const y0 = 40, y1 = 460;
+  const maxHalf = 50; // body half-width → ~100px
+  for (let y = y0; y <= y1; y++) {
+    const t = (y - y0) / (y1 - y0); // 0..1 along length
+    // Cosine taper: tips at ~20% of max width, mid at full
+    const tipFrac = 0.20;
+    const envelope = tipFrac + (1 - tipFrac) * Math.sin(Math.PI * t);
+    const half = Math.max(2, Math.round(maxHalf * envelope));
+    const cx = 120;
+    for (let x = cx - half; x <= cx + half; x++) bitset[y * W + x] = 1;
+  }
+  const ang = (5 * Math.PI) / 180;
+  const ux0 = Math.sin(ang);
+  const uy0 = Math.cos(ang);
+  const rx0 = -uy0;
+  const ry0 = ux0;
+  const cx = 120, cy = 250, halfL = 220, halfW = 70;
+  const corners: [number, number][] = [
+    [cx + ux0 * halfL + rx0 * halfW, cy + uy0 * halfL + ry0 * halfW],
+    [cx + ux0 * halfL - rx0 * halfW, cy + uy0 * halfL - ry0 * halfW],
+    [cx - ux0 * halfL - rx0 * halfW, cy - uy0 * halfL - ry0 * halfW],
+    [cx - ux0 * halfL + rx0 * halfW, cy - uy0 * halfL + ry0 * halfW],
+  ];
+  const bbox = { corners, longSidePx: halfL * 2, angleDeg: 90 - 5 };
+  return { W, H, bitset, bbox, y0, y1, tipFrac: 0.20, maxHalf, ux0, uy0, cx, cy };
+}
+
+test('buildOverlayPlan: tapered tips (~20% max width) included; length span ≥ tip span − small inset (#73)', () => {
+  const { W, H, bitset, bbox, y0, y1, tipFrac, maxHalf, ux0, uy0, cx, cy } = taperedTipFixture();
+  // Sanity: tip bins are ~15–25% of max width (would fail old 0.32 thresh)
+  const tipHalf = Math.max(2, Math.round(maxHalf * tipFrac));
+  const tipWidth = tipHalf * 2 + 1;
+  const bodyWidth = maxHalf * 2 + 1;
+  const tipRatio = tipWidth / bodyWidth;
+  assert.ok(tipRatio >= 0.15 && tipRatio <= 0.25, `fixture tip ratio ${tipRatio.toFixed(3)} in [0.15,0.25]`);
+  assert.ok(tipRatio < 0.32, `fixture tip ratio ${tipRatio.toFixed(3)} must be < old 0.32 thresh`);
+
+  const scale = 10;
+  const wood = maskWoodAabb(bitset, W, H);
+  const slabBounds = {
+    x: wood.minX - 8,
+    y: wood.minY - 8,
+    w: wood.maxX - wood.minX + 16,
+    h: wood.maxY - wood.minY + 16,
+  };
+  const inv = inventorySourceMap(slabBounds, { widthPx: W, heightPx: H }, 900, 1200);
+  const plan = buildOverlayPlan({
+    bitset,
+    widthPx: W,
+    heightPx: H,
+    bbox,
+    scale,
+    lengthIn: 42,
+    lengthLabel: '42"',
+    mapToInventory: inv.mapToInventory,
+  });
+
+  // Width-aware tip stations with current BODY_WIDTH_FRAC
+  const { start: aa, end: bb } = axisEndpoints(bbox);
+  const ex = bb[0] - aa[0], ey = bb[1] - aa[1], elen = Math.hypot(ex, ey) || 1;
+  const ux = ex / elen, uy = ey / elen;
+  const cProj = cx * ux + cy * uy;
+  const rx = -uy, ry = ux;
+  const binMin = new Map<number, number>();
+  const binMax = new Map<number, number>();
+  for (let y = 0; y < H; y++) {
+    for (let x = 0; x < W; x++) {
+      if (!bitset[y * W + x]) continue;
+      const along = x * ux + y * uy;
+      const across = (x - cx) * rx + (y - cy) * ry;
+      const bin = Math.round(along);
+      const prevMin = binMin.get(bin);
+      if (prevMin === undefined || across < prevMin) binMin.set(bin, across);
+      const prevMax = binMax.get(bin);
+      if (prevMax === undefined || across > prevMax) binMax.set(bin, across);
+    }
+  }
+  let maxWidth = 0;
+  const widths: { bin: number; width: number }[] = [];
+  for (const [bin, minA] of binMin) {
+    const maxA = binMax.get(bin)!;
+    const width = maxA - minA + 1;
+    widths.push({ bin, width });
+    if (width > maxWidth) maxWidth = width;
+  }
+  const thresh = Math.max(4, maxWidth * BODY_WIDTH_FRAC);
+  widths.sort((a, b) => a.bin - b.bin);
+  let tipLo = widths[0].bin, tipHi = widths[widths.length - 1].bin;
+  for (const { bin, width } of widths) {
+    if (width >= thresh) { tipLo = bin; break; }
+  }
+  for (let i = widths.length - 1; i >= 0; i--) {
+    if (widths[i].width >= thresh) { tipHi = widths[i].bin; break; }
+  }
+  // Tip bins at the axial extremes must survive the threshold (not dropped)
+  const firstBin = widths[0];
+  const lastBin = widths[widths.length - 1];
+  assert.ok(
+    firstBin.width >= thresh || tipLo <= firstBin.bin + 3,
+    `low tip bin width=${firstBin.width} vs thresh=${thresh.toFixed(1)} must be kept (tipLo=${tipLo} first=${firstBin.bin})`,
+  );
+  assert.ok(
+    lastBin.width >= thresh || tipHi >= lastBin.bin - 3,
+    `high tip bin width=${lastBin.width} vs thresh=${thresh.toFixed(1)} must be kept (tipHi=${tipHi} last=${lastBin.bin})`,
+  );
+  // Axial tip span must reach near the physical wood ends (y0/y1)
+  const tipStart: [number, number] = [cx + ux * (tipLo - cProj), cy + uy * (tipLo - cProj)];
+  const tipEnd: [number, number] = [cx + ux * (tipHi - cProj), cy + uy * (tipHi - cProj)];
+  const oriented = pickBottomTowardTop(tipStart, tipEnd);
+  const mapBot = inv.mapToInventory(oriented.bottom[0], oriented.bottom[1]);
+  const mapTop = inv.mapToInventory(oriented.top[0], oriented.top[1]);
+  const tipAxial = Math.hypot(mapTop[0] - mapBot[0], mapTop[1] - mapBot[1]);
+  const lenAxial = Math.hypot(plan.length.b[0] - plan.length.a[0], plan.length.b[1] - plan.length.a[1]);
+
+  // Length must reach tip stations minus only a small axial inset (tighten old −24px)
+  assert.ok(
+    lenAxial <= tipAxial + 2 && lenAxial >= tipAxial - 8,
+    `length span ${lenAxial.toFixed(1)} must match tip span ${tipAxial.toFixed(1)} within small inset (#73)`,
+  );
+
+  // Prove old 0.32 thresh would have under-reached (fixture is meaningful)
+  const oldThresh = Math.max(4, maxWidth * 0.32);
+  let oldLo = widths[0].bin, oldHi = widths[widths.length - 1].bin;
+  for (const { bin, width } of widths) {
+    if (width >= oldThresh) { oldLo = bin; break; }
+  }
+  for (let i = widths.length - 1; i >= 0; i--) {
+    if (widths[i].width >= oldThresh) { oldHi = widths[i].bin; break; }
+  }
+  assert.ok(
+    (tipHi - tipLo) > (oldHi - oldLo) + 10,
+    `new tip span ${tipHi - tipLo} must exceed old-0.32 span ${oldHi - oldLo} (taper kept)`,
+  );
+
+  // Still no overshoot past wood AABB along axis (keep #69/#71)
+  const woodProjs: number[] = [];
+  for (let y = 0; y < H; y++) {
+    for (let x = 0; x < W; x++) {
+      if (!bitset[y * W + x]) continue;
+      woodProjs.push(x * ux + y * uy);
+    }
+  }
+  woodProjs.sort((a, b) => a - b);
+  const woodSpan = woodProjs[woodProjs.length - 1] - woodProjs[0];
+  const tipSpanSrc = tipHi - tipLo;
+  assert.ok(tipSpanSrc <= woodSpan + 2, `tips must not overshoot wood (${tipSpanSrc} vs ${woodSpan})`);
+});

frontend/src/png/overlay.ts

@@ -82,7 +82,13 @@ export interface OverlayPlanInput {
 }
 
 /**
- * Axial tip stations from across-width profile (#71).
+ * Min across-width as a fraction of max bin width for an axial bin to count as a tip.
+ * #71 used 0.32 (excluded fringe); #73 lowers to ~0.15 so tapered live-edge tips remain.
+ */
+export const BODY_WIDTH_FRAC = 0.15;
+
+/**
+ * Axial tip stations from across-width profile (#71/#73).
  * Thin fringe whiskers past the visible body survive 0.2%/99.8% percentiles;
  * require each axial bin to have meaningful across-width before it counts as a tip.
  */
@@ -121,8 +127,8 @@ function widthAwareAxialRange(
     widths.push({ bin, width });
     if (width > maxWidth) maxWidth = width;
   }
-  // Body threshold: exclude narrow fringe; keep natural mild tapers.
+  // Body threshold: exclude ~10% fringe whiskers; keep 15–25% live-edge tapers (#73).
-  const thresh = Math.max(4, maxWidth * 0.32);
+  const thresh = Math.max(4, maxWidth * BODY_WIDTH_FRAC);
   widths.sort((a, b) => a.bin - b.bin);
   let tipLo = widths[0].bin;
   let tipHi = widths[widths.length - 1].bin;
@@ -282,7 +288,10 @@ export function buildOverlayPlan(input: OverlayPlanInput): OverlayPlan {
   // Inset for stroke + arrowhead so visual tips sit on/inside edges (#71).
   const lineW = Math.max(2, Math.round(fontPx / 10));
   const arrowHead = Math.max(7, fontPx * 0.32);
-  const edgeInset = Math.max(lineW / 2 + 0.5, arrowHead * 0.15);
+  // Width tips retain stroke/arrowhead protection. Length endpoints need only
+  // half-stroke protection: larger arrowhead-derived inset visibly under-reached tips (#73).
+  const widthEdgeInset = Math.max(lineW / 2 + 0.5, arrowHead * 0.15);
+  const lengthEdgeInset = Math.max(0.5, lineW / 2);
   const pad = Math.max(10, Math.min(28, fontPx * 1.1));
   const stations = overlayWidthStations(lengthIn);
   const widths: OverlayWidthMark[] = [];
@@ -300,8 +309,8 @@ export function buildOverlayPlan(input: OverlayPlanInput): OverlayPlan {
     const wlen = Math.hypot(wdx, wdy) || 1;
     const wux = wdx / wlen;
     const wuy = wdy / wlen;
-    const left: [number, number] = [leftMapped[0] + wux * edgeInset, leftMapped[1] + wuy * edgeInset];
+    const left: [number, number] = [leftMapped[0] + wux * widthEdgeInset, leftMapped[1] + wuy * widthEdgeInset];
-    const right: [number, number] = [rightMapped[0] - wux * edgeInset, rightMapped[1] - wuy * edgeInset];
+    const right: [number, number] = [rightMapped[0] - wux * widthEdgeInset, rightMapped[1] - wuy * widthEdgeInset];
     // Width number sits axis-left outside the slab (past left tip).
     const labelOff = extent.minP - pad - fontPx * 0.85;
     const labelSrcW: [number, number] = [ox + rx * labelOff, oy + ry * labelOff];
@@ -337,8 +346,8 @@ export function buildOverlayPlan(input: OverlayPlanInput): OverlayPlan {
   const llen0 = Math.hypot(ldx0, ldy0) || 1;
   const lux = ldx0 / llen0;
   const luy = ldy0 / llen0;
-  const aInv: [number, number] = [aMapped[0] + lux * edgeInset, aMapped[1] + luy * edgeInset];
+  const aInv: [number, number] = [aMapped[0] + lux * lengthEdgeInset, aMapped[1] + luy * lengthEdgeInset];
-  const bInv: [number, number] = [bMapped[0] - lux * edgeInset, bMapped[1] - luy * edgeInset];
+  const bInv: [number, number] = [bMapped[0] - lux * lengthEdgeInset, bMapped[1] - luy * lengthEdgeInset];
   const midInv: [number, number] = [(aInv[0] + bInv[0]) / 2, (aInv[1] + bInv[1]) / 2];
   // Length label further axis-right of dim line so glyphs stay off the wood (#71).
   const mapOrigin = mapToInventory(0, 0);

frontend/src/worker/mask.worker.ts

@@ -1,32 +1,13 @@
 import { minAreaRect, slabBounds } from '../geometry/rect';
 import type { MaskParams, WorkerIn, WorkerOut } from '../capture/capture.types';
 import { decodeOrientedBitmap } from '../decodeOrientedBitmap';
+import { greenKeep, blackKeep, autoPickSheet } from '../mask/sheetKeep';
 
 let bitmap: ImageBitmap | null = null;
 let data: Uint8ClampedArray | null = null;
 let w = 0, h = 0;
 let current = 0; // highest job id issued by main; older replies are dropped
 
-// Keep slab pixels; remove the sheet. Higher sensitivity widens the sheet match.
-const greenKeep = (r: number, g: number, b: number, s: number): boolean => {
-  const t = s / 100;
-  const isSheet = g - Math.max(r, b) > 10 + 35 * t;
-  return !isSheet;
-};
-const blackKeep = (r: number, g: number, b: number, s: number): boolean => {
-  const lum = 0.2126 * r + 0.7152 * g + 0.0722 * b;
-  const isSheet = lum < 40 + 140 * (s / 100);
-  return !isSheet;
-};
-const autoPick = (samples: { r: number; g: number; b: number }[]): 'green' | 'black' => {
-  let gr = 0, gl = 0;
-  for (const p of samples) {
-    if (p.g - Math.max(p.r, p.b) > 20) gr++;
-    if (0.2126 * p.r + 0.7152 * p.g + 0.0722 * p.b < 70) gl++;
-  }
-  return gl >= gr ? 'black' : 'green';
-};
-
 function runMask(params: MaskParams, id: number): WorkerOut {
   if (!data) return { id, kind: 'failed', reason: 'no source decoded' };
   let sheet = params.sheet;
@@ -37,7 +18,7 @@ function runMask(params: MaskParams, id: number): WorkerOut {
         const i = (y * w + x) * 4;
         samples.push({ r: data[i], g: data[i + 1], b: data[i + 2] });
       }
-    sheet = autoPick(samples);
+    sheet = autoPickSheet(samples);
   }
   const keep = sheet === 'green' ? greenKeep : blackKeep;
   const s = Math.max(0, Math.min(100, params.sensitivity));