363 lines
16 KiB
JavaScript
363 lines
16 KiB
JavaScript
/**
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* head-pose.js —— 纯姿态估算模块（yaw / pitch / roll）
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*
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* 输入为 face-api.js 的 68 特征点（[{x,y}, ...]，图片坐标系、未镜像），
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* 输出角度制姿态角。纯数据进、纯数据出：不碰 DOM、不 require face-api，
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* 浏览器挂 window.HeadPose，Node 下 module.exports，可直接单测。
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*
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* ------------------------- 坐标与符号约定 -------------------------
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* 68 点索引（dlib/face-api 约定，以「看图视角」描述）：
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* 36 = 画面左侧眼外角（被摄者右眼外角）
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* 45 = 画面右侧眼外角（被摄者左眼外角）
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* 30 = 鼻尖，33 = 鼻底，19/24 = 左右眉峰，8 = 下巴尖
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* 图片坐标系：x 向右，y 向下。
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*
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* yaw（左右转头）：
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* yaw > 0 表示鼻尖偏向画面右侧（45 点一侧），即被摄者向【自己的左侧】转头
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* （此时画面中看到被摄者的右脸 → check 的 target 'right'）；
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* yaw < 0 表示被摄者向【自己的右侧】转头（画面中看到左脸 → target 'left'）。
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* mirrored=true（前置摄像头预览做了水平镜像）时内部翻转 yaw 符号，
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* 使输出相对用户所看到的画面方向一致；check() 内部会还原语义方向，
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* 因此 check 结果与 mirrored 取值无关。
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* ⚠ 方向符号真机需校准：不同机型/镜像策略下若左右相反，
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* 只需调整调用方传入的 mirrored 标志或 YAW_COEFF 符号。
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*
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* pitch（俯仰）：
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* pitch > 0 表示抬头（鼻底相对眉眼连线中点的纵向下移增大），
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* pitch < 0 表示低头。⚠ 经验映射，真机需校准 PITCH_BASELINE / PITCH_COEFF。
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*
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* roll（平面内歪头）：
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* 两眼外角连线倾角，roll > 0 表示画面右侧（45 点一侧）偏低。
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*
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* 所有映射均为基于 68 点几何的轻量经验估算（非 solvePnP 精确解），
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* 系数仅保证量级与单调性合理，上线前需用真机样本回归校准。
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*/
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(function (root, factory) {
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if (typeof module === 'object' && module.exports) {
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module.exports = factory();
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} else {
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root.HeadPose = factory();
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}
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}(typeof self !== 'undefined' ? self : this, function () {
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'use strict';
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// ---- 68 点索引 ----
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var IDX = {
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EYE_LEFT_OUTER: 36, // 画面左侧眼外角
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EYE_RIGHT_OUTER: 45, // 画面右侧眼外角
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NOSE_TIP: 30,
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NOSE_BASE: 33,
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BROW_LEFT: 19,
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BROW_RIGHT: 24,
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CHIN: 8
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};
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// ---- 经验系数(2026-09-27 用 C3 三视图(+45°侧脸)模拟摄像头校准) ----
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// yaw = atan((dLeft-dRight)/(dLeft+dRight)) × YAW_COEFF。
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// 校准:±45° 实拍侧脸读数 ±25°(2.2 偏小)→ 3.8 使读数落在 44° 上下;正脸 ~4°,仍 <12° 阈值
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var YAW_COEFF = 3.8;
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// pitch:鼻底相对「眉眼连线中点」的纵向偏移 / 脸高(眉 19/24 — 下巴 8),
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// 减去中性正脸基线后线性映射为角度。
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var PITCH_BASELINE = 0.45; // 校准:0.32 时正脸误读 ~29°(被误判低头),实测基线 0.48,留 0.03 余量
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var PITCH_COEFF = 180; // 归一化偏移 → 角度 的增益
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// ---- check 阈值（角度制） ----
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// Real-phone feedback: relaxed alignment, without accepting frontal photos
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// as side views. These empirical angles are not upstream quality scores.
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// 2026-10-15: expand accepted angles by 20%; lower side minimum by 20%.
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var FRONT_YAW_MAX = 18;
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var FRONT_PITCH_MAX = 26;
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var SIDE_YAW_MIN = 24;
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var SIDE_YAW_MAX = 84;
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var SIDE_PITCH_MAX = 29;
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var ROLL_MAX = 22;
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var HINT_KEEP = '保持不动';
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var HINT_TURN_LEFT = '请向左转头'; // 用户向自己的左侧转
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var HINT_TURN_RIGHT = '请向右转头'; // 用户向自己的右侧转
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var HINT_RAISE = '请略微抬头';
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var HINT_LOWER = '请略微低头';
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var HINT_FRONT = '请正对屏幕';
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var RAD2DEG = 180 / Math.PI;
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function dist(a, b) {
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var dx = a.x - b.x;
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var dy = a.y - b.y;
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return Math.sqrt(dx * dx + dy * dy);
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}
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function midpoint(a, b) {
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return { x: (a.x + b.x) / 2, y: (a.y + b.y) / 2 };
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}
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function clamp(v, lo, hi) {
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return v < lo ? lo : (v > hi ? hi : v);
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}
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function assertPoints(points) {
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if (!points || typeof points.length !== 'number' || points.length < 68) {
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throw new TypeError('HeadPose.estimate: 需要 68 个特征点数组');
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}
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var names = Object.keys(IDX);
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for (var i = 0; i < names.length; i++) {
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var p = points[IDX[names[i]]];
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if (!p || typeof p.x !== 'number' || typeof p.y !== 'number' ||
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!isFinite(p.x) || !isFinite(p.y)) {
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throw new TypeError('HeadPose.estimate: 特征点 ' + IDX[names[i]] + ' 非法');
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}
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}
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}
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/**
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* estimate(points, mirrored) -> { yaw, pitch, roll }（角度制），非法/退化输入返回 null
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* points : face-api 68 特征点 [{x,y}, ...]（图片坐标系，未镜像）
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* mirrored : 预览画面是否水平镜像（true 时翻转 yaw 符号）
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* 返回 null 的情形：特征点重合（dLeft+dRight=0，yaw 退化为 NaN）、
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* 脸高过小（pitch 不可信，不再静默置 0）、结果出现 NaN/Infinity。
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*/
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function estimate(points, mirrored) {
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assertPoints(points);
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var eyeL = points[IDX.EYE_LEFT_OUTER];
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var eyeR = points[IDX.EYE_RIGHT_OUTER];
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var noseTip = points[IDX.NOSE_TIP];
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var noseBase = points[IDX.NOSE_BASE];
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var browMid = midpoint(points[IDX.BROW_LEFT], points[IDX.BROW_RIGHT]);
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var chin = points[IDX.CHIN];
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// roll：两眼外角连线倾角（y 向下，45 点偏低为正）
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var roll = Math.atan2(eyeR.y - eyeL.y, eyeR.x - eyeL.x) * RAD2DEG;
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// yaw：鼻尖到左右眼外角距离的不对称度；特征点重合（dLeft+dRight=0）时为 NaN，走非法分支
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var dLeft = dist(noseTip, eyeL);
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var dRight = dist(noseTip, eyeR);
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var dSum = dLeft + dRight;
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var yaw = NaN;
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if (dSum > 0) yaw = Math.atan((dLeft - dRight) / dSum) * RAD2DEG * YAW_COEFF;
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// pitch：鼻底相对眉眼连线中点的纵向偏移，以脸高归一后线性映射；
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// 脸高过小时 pitch 不可信，不再静默置 0，走非法分支
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var eyeMid = midpoint(eyeL, eyeR);
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var browEyeMid = midpoint(browMid, eyeMid);
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var faceHeight = chin.y - browMid.y;
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var pitch = NaN;
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if (faceHeight > 1) {
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var ratio = (noseBase.y - browEyeMid.y) / faceHeight;
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pitch = (ratio - PITCH_BASELINE) * PITCH_COEFF;
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}
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if (!isFinite(yaw) || !isFinite(pitch) || !isFinite(roll)) return null; // 退化输入 → 非法三角
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yaw = clamp(yaw, -90, 90);
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pitch = clamp(pitch, -90, 90);
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if (mirrored) { yaw = -yaw; }
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return { yaw: yaw, pitch: pitch, roll: roll };
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}
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/**
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* check(points, target, mirrored) -> { ok, hint }
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* target: 'front' | 'left' | 'right'
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* 'front' : |yaw|<=18 且 |pitch|<=26、|roll|<=22；角度不合格只提示回正，
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* 不在正脸拍摄完成前播侧脸转头指令。
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* 'left' : 画面中看到左脸 = 被摄者头向右转（语义 yaw ∈ [-84°,-24°]），|pitch|<=29
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* 'right' : 画面中看到右脸 = 被摄者头向左转（语义 yaw ∈ [24°,84°]），|pitch|<=29
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* ok=true 时 hint='保持不动'；输入非法（含 estimate 返回 null 的退化特征点）时 ok=false、hint='请正对屏幕'。
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*/
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function check(points, target, mirrored) {
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var e;
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try {
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e = estimate(points, mirrored);
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} catch (err) {
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return { ok: false, hint: HINT_FRONT, yaw: null };
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}
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if (!e) return { ok: false, hint: HINT_FRONT, yaw: null }; // 退化特征点（重合/脸高过小 → NaN/Infinity）
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// 语义 yaw:>0 = 被摄者向自己的左侧转头。estimate(mirrored) 内部已按镜像翻转过符号,
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// 这里直接用 e.yaw(此前再翻一次是双重镜像 bug:侧脸引导方向完全相反)
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var sYaw = e.yaw;
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var pitch = e.pitch;
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if (Math.abs(e.roll) > ROLL_MAX) return { ok: false, hint: '请勿歪头', yaw: sYaw };
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if (target === 'front') {
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if (Math.abs(sYaw) <= FRONT_YAW_MAX && Math.abs(pitch) <= FRONT_PITCH_MAX) {
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return { ok: true, hint: HINT_KEEP, yaw: sYaw };
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}
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return { ok: false, hint: HINT_FRONT, yaw: sYaw };
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}
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if (target === 'left' || target === 'right') {
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// 'left' 需要语义 yaw 为负（头向右转），'right' 需要为正
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var want = target === 'left' ? -1 : 1;
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var sy = sYaw * want; // 统一折算到正区间判断
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if (sy >= SIDE_YAW_MIN && sy <= SIDE_YAW_MAX && Math.abs(pitch) <= SIDE_PITCH_MAX) {
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return { ok: true, hint: HINT_KEEP, yaw: sYaw };
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}
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if (sy < SIDE_YAW_MIN) {
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// 转得不够（含转错方向）：提示朝目标方向转
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return { ok: false, hint: target === 'left' ? HINT_TURN_RIGHT : HINT_TURN_LEFT, yaw: sYaw };
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}
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if (sy > SIDE_YAW_MAX) {
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// 转过了：提示往回
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return { ok: false, hint: target === 'left' ? HINT_TURN_LEFT : HINT_TURN_RIGHT, yaw: sYaw };
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}
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return { ok: false, hint: pitch > 0 ? HINT_LOWER : HINT_RAISE, yaw: sYaw };
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}
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return { ok: false, hint: HINT_FRONT, yaw: null };
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}
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return {
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estimate: estimate,
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check: check,
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// 导出阈值与系数便于调用方/真机校准阶段调整
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config: {
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YAW_COEFF: YAW_COEFF,
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PITCH_BASELINE: PITCH_BASELINE,
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PITCH_COEFF: PITCH_COEFF,
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FRONT_YAW_MAX: FRONT_YAW_MAX,
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FRONT_PITCH_MAX: FRONT_PITCH_MAX,
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SIDE_YAW_MIN: SIDE_YAW_MIN,
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SIDE_YAW_MAX: SIDE_YAW_MAX,
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SIDE_PITCH_MAX: SIDE_PITCH_MAX,
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ROLL_MAX: ROLL_MAX
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}
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};
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}));
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// -------------------------- Node 自测 --------------------------
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if (typeof module !== 'undefined' && typeof require !== 'undefined' && require.main === module) {
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var HeadPose = module.exports;
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var failures = 0;
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function ok(cond, msg) {
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if (cond) {
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console.log('PASS ' + msg);
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} else {
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failures++;
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console.error('FAIL ' + msg);
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}
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}
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// 合成对称正脸：眼距 100，脸高 170，pitch 偏移恰好落在基线上
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function makeFrontal() {
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var pts = [];
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for (var i = 0; i < 68; i++) { pts.push({ x: 200, y: 150 }); }
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pts[36] = { x: 150, y: 100 }; // 左眼外角（画面左）
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pts[45] = { x: 250, y: 100 }; // 右眼外角（画面右）
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pts[19] = { x: 170, y: 70 };
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pts[24] = { x: 230, y: 70 };
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pts[8] = { x: 200, y: 240 }; // 下巴 → 脸高 240-70=170
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pts[30] = { x: 200, y: 140 }; // 鼻尖居中
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pts[33] = { x: 200, y: 161.5 }; // (161.5-85)/170 = 0.45 = PITCH_BASELINE
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return pts;
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}
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// 把鼻点横向偏移 17.7px，模拟 ~45° 侧脸（向画面右侧偏 = 被摄者向左转；偏移量按 YAW_COEFF=3.8 数值标定）
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function makeSide() {
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var pts = makeFrontal();
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pts[30] = { x: 217.7, y: 140 };
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pts[33] = { x: 217.7, y: 161.5 };
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return pts;
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}
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// 1) 对称正脸 → yaw/pitch/roll ≈ 0
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var front = HeadPose.estimate(makeFrontal(), false);
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ok(Math.abs(front.yaw) < 0.5, '正脸 yaw≈0 (got ' + front.yaw.toFixed(2) + ')');
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ok(Math.abs(front.pitch) < 1, '正脸 pitch≈0 (got ' + front.pitch.toFixed(2) + ')');
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ok(Math.abs(front.roll) < 0.5, '正脸 roll≈0 (got ' + front.roll.toFixed(2) + ')');
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// 2) 正脸 front check 通过
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var fc = HeadPose.check(makeFrontal(), 'front', false);
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ok(fc.ok === true && fc.hint === '保持不动', '正脸 front ok，hint=保持不动');
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// 3) 45° 侧脸：读数落在合理区间
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var side = HeadPose.estimate(makeSide(), false);
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ok(side.yaw > 40 && side.yaw < 50, '侧脸 yaw≈45° (got ' + side.yaw.toFixed(2) + ')');
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// 4) 方向语义：鼻尖偏画面右 = 被摄者向左转 = target 'right' 通过、'left' 拒绝
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var rc = HeadPose.check(makeSide(), 'right', false);
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var lc = HeadPose.check(makeSide(), 'left', false);
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ok(rc.ok === true, '侧脸（被摄者左转）target=right ok');
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ok(lc.ok === false && lc.hint === '请向右转头', '同侧脸 target=left 拒绝并引导向右');
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// 5) mirrored=true 翻转 yaw 符号,check 语义随之翻转(同一点集在镜像预览下对应相反的物理转头)
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var sideM = HeadPose.estimate(makeSide(), true);
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ok(Math.abs(sideM.yaw + side.yaw) < 0.001, 'mirrored=true 时 yaw 符号翻转');
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ok(HeadPose.check(makeSide(), 'right', true).ok === false, 'mirrored 语义翻转:check(right) 拒绝');
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ok(HeadPose.check(makeSide(), 'left', true).ok === true, 'mirrored 语义翻转:check(left) 通过');
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// 6) 反方向侧脸:鼻尖偏画面左 → target 'left' 通过
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var back = makeSide();
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back[30] = { x: 182.3, y: 140 };
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back[33] = { x: 182.3, y: 161.5 };
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var bc = HeadPose.check(back, 'left', false);
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ok(bc.ok === true, '反向侧脸 target=left ok');
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ok(HeadPose.check(back, 'right', false).ok === false, '反向侧脸 target=right 拒绝');
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// 7) 正面步骤只提示回正，不能提前引导拍下一张侧脸。
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var sc = HeadPose.check(makeSide(), 'front', false);
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ok(sc.ok === false && sc.hint === '请正对屏幕', '左转侧脸 front 拒绝，hint=请正对屏幕');
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var scb = makeSide();
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scb[30] = { x: 182.3, y: 140 };
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scb[33] = { x: 182.3, y: 161.5 };
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ok(HeadPose.check(scb, 'front', false).hint === '请正对屏幕', '右转侧脸 front 拒绝，hint=请正对屏幕');
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// 8) roll：右眼（45 点）下移 10px → roll≈5.7°
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var tilted = makeFrontal();
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tilted[45] = { x: 250, y: 110 };
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ok(Math.abs(HeadPose.estimate(tilted, false).roll - 5.71) < 0.2, 'roll≈5.71°');
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// 9) 低头：鼻底上移 → pitch<0，front 拒绝并提示略微抬头
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var down = makeFrontal();
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down[33] = { x: 200, y: 100 };
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var de = HeadPose.estimate(down, false);
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var dc = HeadPose.check(down, 'front', false);
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ok(de.pitch < -30, '低头 pitch<0 (got ' + de.pitch.toFixed(2) + ')');
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ok(dc.ok === false && dc.hint === '请正对屏幕', '低头 front 拒绝，hint=请正对屏幕');
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var up = makeFrontal();
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up[33] = { x: 200, y: 200 };
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ok(HeadPose.check(up, 'front', false).hint === '请正对屏幕', '抬头过多 front 拒绝，hint=请正对屏幕');
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// 10) 非法输入：check 不抛异常，返回兜底引导
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var bad = HeadPose.check(null, 'front', false);
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ok(bad.ok === false && bad.hint === '请正对屏幕', '非法输入兜底 hint=请正对屏幕');
|
||
|
||
// 11) 退化特征点：全部重合 → dLeft+dRight=0 → yaw=NaN → estimate 返回 null，check 兜底「请正对屏幕」（不再误导「请向左转头」）
|
||
var flat = [];
|
||
for (var fi = 0; fi < 68; fi++) { flat.push({ x: 100, y: 100 }); }
|
||
ok(HeadPose.estimate(flat, false) === null, '特征点重合 → estimate 返回 null');
|
||
var fc2 = HeadPose.check(flat, 'front', false);
|
||
ok(fc2.ok === false && fc2.hint === '请正对屏幕', '退化输入 check 兜底 hint=请正对屏幕');
|
||
|
||
// 12) 脸高过小 → pitch 不可信，不再静默置 0，走非法分支
|
||
var tiny = makeFrontal();
|
||
tiny[8] = { x: 200, y: 70.5 }; // faceHeight = 0.5 ≤ 1
|
||
ok(HeadPose.estimate(tiny, false) === null, 'faceHeight 过小 → estimate 返回 null');
|
||
ok(HeadPose.check(tiny, 'front', false).hint === '请正对屏幕', 'faceHeight 过小 check 兜底');
|
||
|
||
// 13) Phone feedback: expand the frontal margin to 18 degrees.
|
||
ok(HeadPose.config.FRONT_YAW_MAX === 18, 'config.FRONT_YAW_MAX = 18');
|
||
var slight = makeFrontal();
|
||
slight[30] = { x: 205.6, y: 140 }; // 偏移 5.6 → yaw≈14.9°(YAW_COEFF=3.8 标定)
|
||
slight[33] = { x: 205.6, y: 161.5 };
|
||
var se = HeadPose.estimate(slight, false);
|
||
ok(se.yaw > 13.5 && se.yaw <= 15, '轻微偏头 yaw∈(13.5,15] (got ' + se.yaw.toFixed(2) + ')');
|
||
var sc2 = HeadPose.check(slight, 'front', false);
|
||
ok(sc2.ok === true, 'yaw≈14.9° front 通过（真机反馈放宽）');
|
||
var slight2 = makeFrontal();
|
||
slight2[30] = { x: 206.2, y: 140 }; // 偏移 6.2 → yaw≈16.2°
|
||
slight2[33] = { x: 206.2, y: 161.5 };
|
||
var se2 = HeadPose.estimate(slight2, false);
|
||
ok(se2.yaw > 15 && se2.yaw < 17.5, '偏头 yaw∈(15,17.5) (got ' + se2.yaw.toFixed(2) + ')');
|
||
var sc3 = HeadPose.check(slight2, 'front', false);
|
||
ok(sc3.ok === true, 'yaw≈16.2° front 通过（放宽20%）');
|
||
|
||
if (failures > 0) {
|
||
console.error('\n' + failures + ' 项自测失败');
|
||
process.exit(1);
|
||
}
|
||
console.log('\n全部自测通过');
|
||
}
|