From d05c5188506d8b16a31a91adbc873ccb7f12ad9d Mon Sep 17 00:00:00 2001
From: Redstone OLD <3069884909@qq.com>
Date: Mon, 24 Nov 2025 09:54:45 +0800
Subject: [PATCH] 1124

---
 DigitalImageProcessing/Program.cs      |  3 +-
 DigitalImageProcessing/Segmentation.cs | 54 ++++++++++++++++++++++++--
 2 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/DigitalImageProcessing/Program.cs b/DigitalImageProcessing/Program.cs
index e5b776b..a77889c 100644
--- a/DigitalImageProcessing/Program.cs
+++ b/DigitalImageProcessing/Program.cs
@@ -1,7 +1,8 @@
 using DigitalImageProcessing;
 using SkiaSharp;
 
-Segmentation.Run();
+Segmentation.Run1(2);
+Segmentation.Run2();
 
 //string testImage = @"C:\Users\Surface\Downloads\" + @"1682575881230001.png";
 ////Alograms.Steps(@"C:\Users\Surface\Downloads\", @"C:\Users\Surface\Downloads\" + @"1682575881230001.png");
diff --git a/DigitalImageProcessing/Segmentation.cs b/DigitalImageProcessing/Segmentation.cs
index ae6d5c9..fc803fd 100644
--- a/DigitalImageProcessing/Segmentation.cs
+++ b/DigitalImageProcessing/Segmentation.cs
@@ -2,15 +2,15 @@
 {
     internal static class Segmentation
     {
-        public static void Run()
+        private const float _0 = 1e-6f;
+        public static void Run1(int thresholdDelta)
         {
             int thresholdValue = 128;
-            int thresholdDelta = 5;
 
             float delta = float.MaxValue;
             int loopCount = 0;
 
-            int[,] grayImage = GLobalTools.GetGrayAsArray(@"C:\Users\Surface\Downloads\OIP.webp");
+            int[,] grayImage = GLobalTools.GetGrayAsArray(@"C:\Users\Surface\Downloads\Sprite-0001.png");
 
             while (delta > thresholdDelta)
             {
@@ -29,9 +29,55 @@
                 thresholdValue = thres;
                 Console.WriteLine($"Current Threshold Value: {thres}, Delta: {delta}");
             }
-            Console.WriteLine($"Final Threshold Value: {thresholdValue} found in {loopCount} loops.");
+            Console.WriteLine($"Threshold Value: {thresholdValue} found in {loopCount} loops.");
             int[,] foreground = grayImage.Select(i => i > thresholdValue ? 255 : 0);
             foreground.Save(@"C:\Users\Surface\Downloads\OIP_foreground.webp");
         }
+        public static void Run2()
+        {
+            int[,] gray = GLobalTools.GetGrayAsArray(@"C:\Users\Surface\Downloads\Sprite-0001.png");
+            int[] pixels = new int[254];
+            int size = 0;
+
+
+            for (int i = 0; i < gray.GetLength(0); i++)
+                for (int j = 0; j < gray.GetLength(1); j++)
+                    if (gray[i, j] is > 0 and < 255)
+                    {
+                        pixels[gray[i, j] - 1]++;
+                        size++;
+                    }
+
+            float[] pws = new float[pixels.Length]; // 类概率
+            int mut = 0;
+            for (int t = 0; t < pixels.Length; t++)
+            {
+                pws[t] = (float)pixels[t] / size;
+                mut += t * pixels[t];
+            }
+
+            float w0 = 0; // 类内概率
+            float mu0 = 0; // 类内均值
+            float wxmax = 0; // 类间方差最大值
+            int threshold = 0;
+            for (int t = 0; t < pixels.Length; t++)
+            {
+                w0 += pws[t];
+                mu0 += t * pws[t];
+                float w1 = 1 - w0;
+                if (w0 < _0 || w1 < _0) continue;
+                float mu1 = (mut - mu0) / w1;
+                mu0 /= w0;
+                float wx = w0 * w1 * (mu0 / w0 - mu1) * (mu0 / w0 - mu1);
+                if (wx > wxmax)
+                {
+                    wxmax = wx;
+                    threshold = t + 1;
+                }
+            }
+            Console.WriteLine($"Threshold Value: {threshold}");
+            int[,] foreground = gray.Select(i => i > threshold ? 255 : 0);
+            foreground.Save(@"C:\Users\Surface\Downloads\OIP_foreground.webp");
+        }
     }
 }