fix(camera): relax initial frontal face recognition

h5/js/app.js

@@ -607,7 +607,7 @@
       var img = new Image();
       img.onload = function () {
         faceapi
-          .detectAllFaces(img, new faceapi.TinyFaceDetectorOptions({ inputSize: DETECT_INPUT_SIZE, scoreThreshold: DETECT_SCORE }))
+          .detectAllFaces(img, new faceapi.TinyFaceDetectorOptions({ inputSize: DETECT_INPUT_SIZE, scoreThreshold: CaptureQuality.scoreThreshold(target) }))
           .withFaceLandmarks()
           .then(function (faces) {
             var d = faces[0], box = d && d.detection.box;
@@ -768,8 +768,8 @@
   var MODEL_URL = 'vendor/faceapi/models';
   var DETECT_INTERVAL = 150;   // 检测帧间隔(ms)
   var DETECT_INPUT_SIZE = 416; // tinyFaceDetector 输入尺寸:320 下正脸置信度仅 0.67 且框偏松,416 置信度 ~0.99 框更准(CPU 端略慢,移动端 GPU 无感)
-  var DETECT_SCORE = CaptureQuality.config.score;
   var MISS_FRAMES_MAX = 3;     // 连续漏检 ≥3 帧(~450ms)才报「未检测到人脸」,容忍单帧抖动
+  var FRONT_MISS_FRAMES_MAX = 6; // 正面首次发现人脸前，多给相机对焦/曝光几次检测机会。
   var NO_PROGRESS_MS = 12000;  // 单步超过该时长仍未抓拍→浮出调整提示
   var PREVIEW_SCALE = 1;       // 与 CSS #cam-video 铺满预览一致，镜像只改变方向
 
@@ -860,6 +860,7 @@
     holdState = null;
     resetAngleHaptic();
     missFrames = 0;
+    frontFaceSeen = false;
     oppFrames = 0;
     lastHint = '';
     clearTimeout(nudgeTimer);
@@ -913,7 +914,7 @@
     if (shutterLock || capturing || !camLive) return Promise.resolve(); // 抓帧/流程推进中不判姿态
     var step = camStep, seq = camSeq, generation = detGeneration; // 旧镜头推理结果不能污染新镜头
     return faceapi
-      .detectAllFaces(camVideo, new faceapi.TinyFaceDetectorOptions({ inputSize: DETECT_INPUT_SIZE, scoreThreshold: DETECT_SCORE }))
+      .detectAllFaces(camVideo, new faceapi.TinyFaceDetectorOptions({ inputSize: DETECT_INPUT_SIZE, scoreThreshold: CaptureQuality.scoreThreshold(CAM_STEPS[step].target) }))
       .withFaceLandmarks()
       .then(function (d) {
         if (step !== camStep || seq !== camSeq || generation !== detGeneration) return;
@@ -941,6 +942,7 @@
     } catch (e) { return null; }
   }
   var missFrames = 0; // 连续漏检帧计数:单帧抖动不报「未检测到人脸」
+  var frontFaceSeen = false;
   /* camera-haptic-pure-begin */
   function captureHaptic(nav) {
     // Unsupported/blocked vibration must never interrupt automatic capture.
@@ -976,7 +978,10 @@
     if (Array.isArray(d)) d = d[0];
     var hint = '', ok = false;
     missFrames = d ? 0 : missFrames + 1;
-    var hasFace = !!d, noFace = !hasFace && missFrames >= MISS_FRAMES_MAX;
+    var hasFace = !!d;
+    if (hasFace && CAM_STEPS[camStep].target === 'front') frontFaceSeen = true;
+    var missLimit = CAM_STEPS[camStep].target === 'front' && !frontFaceSeen ? FRONT_MISS_FRAMES_MAX : MISS_FRAMES_MAX;
+    var noFace = !hasFace && missFrames >= missLimit;
     if (noFace) {
       hint = '未检测到人脸';
     } else if (!hasFace) {

h5/js/capture-quality.js

@@ -6,11 +6,12 @@
   'use strict';
   // Real-phone feedback: ease alignment and normal hand/head movement while
   // retaining two checked frames, one face, framing and final JPEG validation.
-  var config = Object.freeze({ version: '2026-10-15-pitch-roll-relaxed-v7', score: 0.4,
+  var config = Object.freeze({ version: '2026-10-16-front-detection-v8', score: 0.4, frontScore: 0.3,
     near: 0.30, far: 0.68, center: 0.16, edge: 0.01,
     dark: 110, bright: 220, holdMs: 450, minFrames: 2, maxGapMs: 2000,
     yawDrift: 8, pitchDrift: 8, centerDrift: 0.055, sizeDrift: 0.065 });
   function finite(v) { return typeof v === 'number' && isFinite(v); }
+  function scoreThreshold(target) { return target === 'front' ? config.frontScore : config.score; }
   function evaluate(d, options) {
     var failed = function(hint, reason) { return { ok: false, hint: hint, reason: reason || 'quality' }; };
     if (!d) return failed('未检测到人脸');
@@ -18,7 +19,7 @@
     var box = d.detection.box, w = options.width, h = options.height;
     if (!box || ![box.x, box.y, box.width, box.height, w, h].every(finite) || w <= 0 || h <= 0 || box.width <= 0 || box.height <= 0) return failed('请将脸部完整移入取景框');
     var ratio = box.height / h;
-    if (!finite(d.detection.score) || d.detection.score < config.score) return failed('请保持面部清晰');
+    if (!finite(d.detection.score) || d.detection.score < scoreThreshold(options.target)) return failed('请保持面部清晰');
     if (ratio < config.near) return failed('请靠近一点');
     if (ratio > config.far) return failed('请远一点');
     if (box.x < w * config.edge || box.y < h * config.edge || box.x + box.width > w * (1 - config.edge) || box.y + box.height > h * (1 - config.edge)) return failed('请将脸部完整移入取景框');
@@ -51,5 +52,5 @@
       { since: state.since, lastAt: now, frames: state.frames + 1, anchor: state.anchor };
     return { state: next, ready: now - next.since >= config.holdMs && next.frames >= config.minFrames };
   }
-  return { config: config, evaluate: evaluate, hold: hold };
+  return { config: config, scoreThreshold: scoreThreshold, evaluate: evaluate, hold: hold };
 });