迁移 Flutter 端与训练脚本，模型/训练产物移出 git（遵循纯代码约定）

2026-08-24 12:35:24 +08:00
parent d056f01965
commit 961523d94c
218 changed files with 13391 additions and 3232 deletions
@@ -0,0 +1,113 @@
+import 'dart:math' as math;
+import 'dart:typed_data';
+
+import 'detection_result.dart';
+
+/// 运行时视觉先验：对低置信度野鸡框做多线索过滤，降低户外误报。
+///
+/// 仅对 score < [maxScore]（0.35）的 pheasant 框生效；高分框与
+/// suspect（生境预警）不参与过滤，避免误杀。
+///
+/// 线索：
+/// - 颜色：绿色主导（草/叶）、蓝色主导（天空/水）、平坦低饱和（键盘/石头/文字）
+/// - 位置：中心在画面上部 15%（天空区）——野鸡是地栖动物，不会出现在天空
+///
+/// 采样在原始 planes 上进行（后台 isolate 内，不依赖 UI 线程）。
+class VisualPrior {
+  static const double maxScore = 0.35;
+  static const double skyTopRatio = 0.15;
+
+  // 颜色判定阈值（与 tflite_detector 的 YUV 有限范围展开一致）
+  static const double greenDiff = 20;
+  static const double blueDiff = 10;
+  static const double flatRange = 10;
+
+  // 采样点中满足条件的比例超过即拒绝
+  static const double greenRatio = 0.5;
+  static const double blueRatio = 0.4;
+  static const double flatRatio = 0.6;
+
+  static List<DetectionResult> filter(
+    List<DetectionResult> results, {
+    required List<Uint8List> planes,
+    required List<int> strides,
+    required int width,
+    required int height,
+    required bool isBgra,
+  }) {
+    if (results.isEmpty || width <= 0 || height <= 0) return results;
+    final kept = <DetectionResult>[];
+    for (final r in results) {
+      final lowConfPheasant = r.label == 'pheasant' && r.score < maxScore;
+      if (lowConfPheasant && _reject(r, planes, strides, width, height, isBgra)) {
+        continue;
+      }
+      kept.add(r);
+    }
+    return kept;
+  }
+
+  static bool _reject(DetectionResult r, List<Uint8List> planes,
+      List<int> strides, int width, int height, bool isBgra) {
+    // 位置线索：detectRaw 输出为图像坐标系，centerY 直接可判天空区
+    if (r.centerY < skyTopRatio) return true;
+
+    // 颜色线索：框中心 ±20% 区域 5×5 采样（小框采样点重合也没关系）
+    final cx = (r.centerX * width).round().clamp(0, width - 1).toInt();
+    final cy = (r.centerY * height).round().clamp(0, height - 1).toInt();
+    final halfW = math.max(1.0, r.width * width * 0.2);
+    final halfH = math.max(1.0, r.height * height * 0.2);
+
+    var green = 0, blue = 0, flat = 0, total = 0;
+    for (var gy = -2; gy <= 2; gy++) {
+      for (var gx = -2; gx <= 2; gx++) {
+        final px = (cx + gx * halfW / 2).round().clamp(0, width - 1).toInt();
+        final py = (cy + gy * halfH / 2).round().clamp(0, height - 1).toInt();
+        final (r_, g_, b_) = _pixel(planes, strides, px, py, width, height, isBgra);
+        total++;
+        final mn = math.min(r_, math.min(g_, b_));
+        final mx = math.max(r_, math.max(g_, b_));
+        if (g_ - r_ > greenDiff && g_ - b_ > greenDiff) green++;
+        if (b_ > r_ + blueDiff) blue++;
+        if (mx - mn < flatRange) flat++;
+      }
+    }
+    if (total == 0) return false;
+    if (green / total > greenRatio) return true;
+    if (blue / total > blueRatio) return true;
+    if (flat / total > flatRatio) return true;
+    return false;
+  }
+
+  /// 读取单像素 RGB（0~255）。
+  /// BGRA 单平面：每像素 4 字节 [b,g,r,a]；
+  /// YUV：y 平面 + 4:2:0 半分辨率 U/V（NV12 交错或 I420 分离）。
+  static (double, double, double) _pixel(List<Uint8List> planes,
+      List<int> strides, int x, int y, int width, int height, bool isBgra) {
+    if (isBgra) {
+      final src = planes[0];
+      final i = y * strides[0] + x * 4;
+      return (src[i + 2].toDouble(), src[i + 1].toDouble(), src[i].toDouble());
+    }
+    final yy =
+        (planes[0][y * strides[0] + x] - 16.0) * (255.0 / 219.0);
+    final nv12 = planes.length == 2;
+    final ux = (x ~/ 2).clamp(0, width ~/ 2 - 1).toInt();
+    final uy = (y ~/ 2).clamp(0, height ~/ 2 - 1).toInt();
+    final uvStride = strides[1];
+    final un = ((nv12
+                ? planes[1][uy * uvStride + ux * 2].toDouble()
+                : planes[1][uy * uvStride + ux].toDouble()) -
+            128.0) *
+        (255.0 / 224.0);
+    final vn = ((nv12
+                ? planes[1][uy * uvStride + ux * 2 + 1].toDouble()
+                : planes[2][uy * uvStride + ux].toDouble()) -
+            128.0) *
+        (255.0 / 224.0);
+    final r = yy + 1.402 * vn;
+    final g = yy - 0.344136 * un - 0.714136 * vn;
+    final b = yy + 1.772 * un;
+    return (r, g, b);
+  }
+}