白底/黑底检测：轮廓与最远弦度量，UI 分色与标注优化

- 算子：输出轮廓顶点及顶点间最远弦（微米标定与原先一致）

- 视图：实线轮廓；白底红/黑底绿；尺寸文字置于 ROI 外右侧垂直居中

- 事件与 MainViewModel 载荷改为 BackgroundDefectDetectionItem

Co-authored-by: Cursor <cursoragent@cursor.com>

XP.ImageProcessing.Processors/检测分析/BackgroundDefectAnalyzer.cs

@@ -2,10 +2,11 @@
 // Copyright © 2026 Hexagon Technology Center GmbH. All Rights Reserved.
 // 文件名: BackgroundDefectAnalyzer.cs
 // 描述: 白底/黑底对比下的缺陷斑点分析（仅 ROI 内计算，不接入流水线算子）
-// 算法: Otsu 二值化 → 形态学开运算 → 外轮廓 → 面积过滤 → 外接矩形等效圆
+// 算法: Otsu 二值化 → 形态学开运算 → 外轮廓 → 面积过滤 → 轮廓顶点最远弦（物理长度与历史等效直径同一标定：mm/px → μm）
 // 作者: 李伟 wei.lw.li@hexagon.com
 // ============================================================================
 
+using System.Collections.Generic;
 using System.Drawing;
 using Emgu.CV;
 using Emgu.CV.CvEnum;
@@ -27,9 +28,15 @@ public enum BackgroundDefectMode
 }
 
 /// <summary>
-/// 单个斑点，坐标相对于输入 ROI 左上角；<see cref="SizeMicrometers"/> 与主界面标注逻辑一致（等效直径，微米）。
+/// 单个斑点：轮廓顶点相对于 ROI 左上角；<see cref="MaxChordMicrometers"/> 为轮廓顶点间欧氏距离最大值（微米）。
 /// </summary>
-public readonly record struct BackgroundDefectBlob(Point CenterInRoi, int RadiusPixels, double SizeMicrometers);
+public sealed class BackgroundDefectBlob
+{
+    public Point[] ContourInRoi { get; init; } = Array.Empty<Point>();
+    public double MaxChordMicrometers { get; init; }
+    public Point MaxChordEndAInRoi { get; init; }
+    public Point MaxChordEndBInRoi { get; init; }
+}
 
 /// <summary>
 /// 在灰度 ROI 上执行底色缺陷斑点检测。调用方负责构造与释放 <paramref name="roiGray"/>。
@@ -42,7 +49,7 @@ public static class BackgroundDefectAnalyzer
     /// <param name="roiGray">ROI 灰度图（单通道 8 位）。</param>
     /// <param name="mode">白底或黑底模式。</param>
     /// <param name="minAreaPixels">轮廓最小面积（像素²），小于此值的轮廓丢弃。</param>
-    /// <param name="mmPerPixel">像素物理尺寸（毫米/像素），用于等效直径换算。</param>
+    /// <param name="mmPerPixel">像素物理尺寸（毫米/像素），用于轮廓最远弦换算为微米。</param>
     /// <param name="morphKernelSize">形态学开运算核尺寸（奇数，默认 3）。</param>
     public static List<BackgroundDefectBlob> DetectBlobs(
         Image<Gray, byte> roiGray,
@@ -84,19 +91,56 @@ public static class BackgroundDefectAnalyzer
             double area = CvInvoke.ContourArea(contours[i]);
             if (area < minAreaPixels) continue;
 
-            var boundRect = CvInvoke.BoundingRectangle(contours[i]);
-            double radiusF = Math.Max(boundRect.Width, boundRect.Height) / 2.0;
-            var centerF = new PointF(
-                boundRect.X + boundRect.Width / 2.0f,
-                boundRect.Y + boundRect.Height / 2.0f);
+            int n = contours[i].Size;
+            if (n < 2) continue;
 
-            var centerInRoi = new Point((int)centerF.X, (int)centerF.Y);
-            int radiusPx = (int)radiusF;
-            double sizeMicrometers = radiusF * 2.0 * mmPerPixel * 1000.0;
+            var pts = new Point[n];
+            for (int j = 0; j < n; j++)
+                pts[j] = contours[i][j];
 
-            result.Add(new BackgroundDefectBlob(centerInRoi, radiusPx, sizeMicrometers));
+            MaxChordInPixelSpace(pts, out double maxChordPx, out Point pa, out Point pb);
+            double maxChordMicrometers = maxChordPx * mmPerPixel * 1000.0;
+
+            result.Add(new BackgroundDefectBlob
+            {
+                ContourInRoi = pts,
+                MaxChordMicrometers = maxChordMicrometers,
+                MaxChordEndAInRoi = pa,
+                MaxChordEndBInRoi = pb
+            });
         }
 
         return result;
     }
+
+    /// <summary>轮廓顶点集合上的最远点对（欧氏距离，像素）。</summary>
+    private static void MaxChordInPixelSpace(Point[] pts, out double maxChordPx, out Point a, out Point b)
+    {
+        maxChordPx = 0;
+        a = pts[0];
+        b = pts.Length > 1 ? pts[1] : pts[0];
+        long bestSq = 0;
+        int bestI = 0, bestJ = 1;
+        int n = pts.Length;
+        for (int i = 0; i < n; i++)
+        {
+            int iX = pts[i].X, iY = pts[i].Y;
+            for (int j = i + 1; j < n; j++)
+            {
+                long dx = iX - pts[j].X;
+                long dy = iY - pts[j].Y;
+                long sq = dx * dx + dy * dy;
+                if (sq > bestSq)
+                {
+                    bestSq = sq;
+                    bestI = i;
+                    bestJ = j;
+                }
+            }
+        }
+
+        a = pts[bestI];
+        b = pts[bestJ];
+        maxChordPx = Math.Sqrt(bestSq);
+    }
 }

XplorePlane/Events/MeasurementToolEvent.cs

@@ -1,7 +1,21 @@
+using System.Collections.Generic;
+using System.Drawing;
 using Prism.Events;
 
 namespace XplorePlane.Events
 {
+    /// <summary>
+    /// 白底/黑底检测单条结果：全局图像坐标下的轮廓与最远弦（微米与既有展示规则一致）。
+    /// </summary>
+    public class BackgroundDefectDetectionItem
+    {
+        public List<Point> Contour { get; set; } = new();
+        /// <summary>轮廓顶点间最远距离（微米）。</summary>
+        public double SizeMicrometers { get; set; }
+        public Point ChordP1 { get; set; }
+        public Point ChordP2 { get; set; }
+    }
+
     /// <summary>
     /// 测量工具模式
     /// </summary>
@@ -49,7 +63,7 @@ namespace XplorePlane.Events
     public class WhiteBackgroundResultPayload
     {
         public System.Drawing.Rectangle RoiRect { get; set; }
-        public System.Collections.Generic.List<(System.Drawing.Point center, int radius, double sizeMm)> Detections { get; set; }
+        public List<BackgroundDefectDetectionItem> Detections { get; set; } = new();
     }
 
     /// <summary>
@@ -70,6 +84,6 @@ namespace XplorePlane.Events
     public class BlackBackgroundResultPayload
     {
         public System.Drawing.Rectangle RoiRect { get; set; }
-        public System.Collections.Generic.List<(System.Drawing.Point center, int radius, double sizeMm)> Detections { get; set; }
+        public List<BackgroundDefectDetectionItem> Detections { get; set; } = new();
     }
 }

XplorePlane/ViewModels/Main/MainViewModel.cs

@@ -1011,11 +1011,18 @@ namespace XplorePlane.ViewModels
                 const double mmPerPixel = 0.139;
                 var blobs = BackgroundDefectAnalyzer.DetectBlobs(roiImage, mode, minArea, mmPerPixel);
 
-                var detections = new System.Collections.Generic.List<(System.Drawing.Point center, int radius, double sizeMm)>(blobs.Count);
+                var detections = new System.Collections.Generic.List<BackgroundDefectDetectionItem>(blobs.Count);
                 foreach (var b in blobs)
                 {
-                    var globalCenter = new System.Drawing.Point(b.CenterInRoi.X + rx, b.CenterInRoi.Y + ry);
-                    detections.Add((globalCenter, b.RadiusPixels, b.SizeMicrometers));
+                    var item = new BackgroundDefectDetectionItem
+                    {
+                        SizeMicrometers = b.MaxChordMicrometers,
+                        ChordP1 = new System.Drawing.Point(b.MaxChordEndAInRoi.X + rx, b.MaxChordEndAInRoi.Y + ry),
+                        ChordP2 = new System.Drawing.Point(b.MaxChordEndBInRoi.X + rx, b.MaxChordEndBInRoi.Y + ry)
+                    };
+                    foreach (var p in b.ContourInRoi)
+                        item.Contour.Add(new System.Drawing.Point(p.X + rx, p.Y + ry));
+                    detections.Add(item);
                 }
 
                 var roiRect = new System.Drawing.Rectangle(rx, ry, rw, rh);

XplorePlane/Views/Main/ViewportPanelView.xaml.cs

@@ -155,16 +155,16 @@ namespace XplorePlane.Views
                     RegisterBackgroundDefectRoiMouseHandlers();
                 }, Prism.Events.ThreadOption.UIThread);
 
-                // 白底检测：渲染结果
+                // 白底检测：渲染结果（红色标识）
                 ea2?.GetEvent<WhiteBackgroundResultEvent>().Subscribe(payload =>
                 {
-                    RenderBackgroundDefectResult(payload.RoiRect, payload.Detections);
+                    RenderBackgroundDefectResult(payload.RoiRect, payload.Detections, isBlackBackground: false);
                 }, Prism.Events.ThreadOption.UIThread);
 
-                // 黑底检测：渲染结果
+                // 黑底检测：渲染结果（绿色标识）
                 ea2?.GetEvent<BlackBackgroundResultEvent>().Subscribe(payload =>
                 {
-                    RenderBackgroundDefectResult(payload.RoiRect, payload.Detections);
+                    RenderBackgroundDefectResult(payload.RoiRect, payload.Detections, isBlackBackground: true);
                 }, Prism.Events.ThreadOption.UIThread);
             }
             catch { }
@@ -542,12 +542,13 @@ namespace XplorePlane.Views
 
         private void RenderBackgroundDefectResult(
             System.Drawing.Rectangle roiRect,
-            System.Collections.Generic.List<(System.Drawing.Point center, int radius, double sizeMm)> detections)
+            System.Collections.Generic.IReadOnlyList<BackgroundDefectDetectionItem> detections,
+            bool isBlackBackground)
         {
             var canvas = FindChildByName<System.Windows.Controls.Canvas>(RoiCanvas, "mainCanvas");
             if (canvas == null || detections == null) return;
 
-            // 绘制ROI矩形（蓝色实线）
+            // 绘制ROI矩形（蓝色实线，两种模式一致）
             var roiShape = new System.Windows.Shapes.Rectangle
             {
                 Stroke = System.Windows.Media.Brushes.Blue,
@@ -561,52 +562,74 @@ namespace XplorePlane.Views
             canvas.Children.Add(roiShape);
             _bgDefectOverlays.Add(roiShape);
 
-            // 绘制每个检测区域（白底为暗区、黑底为亮区，可视化相同）
-            foreach (var (center, radius, sizeMm) in detections)
+            var defectBrush = isBlackBackground
+                ? System.Windows.Media.Brushes.LimeGreen
+                : System.Windows.Media.Brushes.Red;
+
+            const int labelPadRightOfRoi = 4;
+            const double labelLineHeight = 15;
+            int validCount = detections.Count(d => d.Contour != null && d.Contour.Count >= 2);
+            double roiMidY = roiRect.Y + roiRect.Height * 0.5;
+            double labelLeft = roiRect.X + roiRect.Width + labelPadRightOfRoi;
+            double labelStartY = roiMidY - validCount * labelLineHeight * 0.5;
+            int labelRow = 0;
+
+            foreach (var d in detections)
             {
-                // 红色虚线圆
-                var circle = new System.Windows.Shapes.Ellipse
+                if (d.Contour == null || d.Contour.Count < 2) continue;
+
+                var fig = new PathFigure
                 {
-                    Stroke = System.Windows.Media.Brushes.Red,
+                    StartPoint = new System.Windows.Point(d.Contour[0].X, d.Contour[0].Y),
+                    IsClosed = true
+                };
+                if (d.Contour.Count > 1)
+                {
+                    fig.Segments.Add(new PolyLineSegment(
+                        d.Contour.Skip(1).Select(p => new System.Windows.Point(p.X, p.Y)), true));
+                }
+
+                var geom = new PathGeometry();
+                geom.Figures.Add(fig);
+                var contourPath = new System.Windows.Shapes.Path
+                {
+                    Data = geom,
+                    Stroke = defectBrush,
                     StrokeThickness = 1,
-                    StrokeDashArray = new System.Windows.Media.DoubleCollection { 4, 2 },
-                    Width = radius * 2,
-                    Height = radius * 2,
+                    Fill = System.Windows.Media.Brushes.Transparent,
                     IsHitTestVisible = false
                 };
-                System.Windows.Controls.Canvas.SetLeft(circle, center.X - radius);
-                System.Windows.Controls.Canvas.SetTop(circle, center.Y - radius);
-                canvas.Children.Add(circle);
-                _bgDefectOverlays.Add(circle);
+                canvas.Children.Add(contourPath);
+                _bgDefectOverlays.Add(contourPath);
 
-                // 45°直径标注线（从圆心向左上到右下）
-                double offset = radius * 0.707; // cos(45°) * radius
-                var diamLine = new System.Windows.Shapes.Line
+                var chordLine = new System.Windows.Shapes.Line
                 {
-                    X1 = center.X - offset,
-                    Y1 = center.Y - offset,
-                    X2 = center.X + offset,
-                    Y2 = center.Y + offset,
-                    Stroke = System.Windows.Media.Brushes.Red,
-                    StrokeThickness = 1,
+                    X1 = d.ChordP1.X,
+                    Y1 = d.ChordP1.Y,
+                    X2 = d.ChordP2.X,
+                    Y2 = d.ChordP2.Y,
+                    Stroke = defectBrush,
+                    StrokeThickness = 1.5,
                     IsHitTestVisible = false
                 };
-                canvas.Children.Add(diamLine);
-                _bgDefectOverlays.Add(diamLine);
+                canvas.Children.Add(chordLine);
+                _bgDefectOverlays.Add(chordLine);
+
+                double um = d.SizeMicrometers;
+                string label = um >= 1000 ? $"{um / 1000:F2} mm" : $"{um:F0} μm";
 
-                // 尺寸标注（在斜线右上方）
-                string label = sizeMm >= 1000 ? $"{sizeMm / 1000:F2} mm" : $"{sizeMm:F0} μm";
                 var text = new System.Windows.Controls.TextBlock
                 {
                     Text = label,
-                    Foreground = System.Windows.Media.Brushes.Red,
+                    Foreground = defectBrush,
                     FontSize = 11,
                     IsHitTestVisible = false
                 };
-                System.Windows.Controls.Canvas.SetLeft(text, center.X + offset + 3);
-                System.Windows.Controls.Canvas.SetTop(text, center.Y - offset - 14);
+                System.Windows.Controls.Canvas.SetLeft(text, labelLeft);
+                System.Windows.Controls.Canvas.SetTop(text, labelStartY + labelRow * labelLineHeight);
                 canvas.Children.Add(text);
                 _bgDefectOverlays.Add(text);
+                labelRow++;
             }
         }