work on well of souls and yolo detection

src/Poe2Trade.Screen/ScreenReader.cs

@@ -1,6 +1,10 @@
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.Runtime.InteropServices;
 using Poe2Trade.Core;
 using OpenCvSharp.Extensions;
 using Serilog;
+using Region = Poe2Trade.Core.Region;
 
 namespace Poe2Trade.Screen;
 
@@ -178,6 +182,144 @@ public class ScreenReader : IScreenReader
         return Task.CompletedTask;
     }
 
+    // -- Nameplate diff OCR --
+
+    public Bitmap CaptureRawBitmap() => ScreenCapture.CaptureOrLoad(null, null);
+
+    public Task<OcrResponse> NameplateDiffOcr(Bitmap reference, Bitmap current)
+    {
+        int w = Math.Min(reference.Width, current.Width);
+        int h = Math.Min(reference.Height, current.Height);
+
+        var refData = reference.LockBits(new Rectangle(0, 0, w, h), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
+        var curData = current.LockBits(new Rectangle(0, 0, w, h), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
+        byte[] refPx = new byte[refData.Stride * h];
+        byte[] curPx = new byte[curData.Stride * h];
+        Marshal.Copy(refData.Scan0, refPx, 0, refPx.Length);
+        Marshal.Copy(curData.Scan0, curPx, 0, curPx.Length);
+        int stride = refData.Stride;
+        reference.UnlockBits(refData);
+        current.UnlockBits(curData);
+
+        // Build a binary mask of pixels that got significantly brighter (nameplates are bright text)
+        const int brightThresh = 30;
+        bool[] mask = new bool[w * h];
+        Parallel.For(0, h, y =>
+        {
+            int rowOff = y * stride;
+            for (int x = 0; x < w; x++)
+            {
+                int i = rowOff + x * 4;
+                int brighter = (curPx[i] - refPx[i]) + (curPx[i + 1] - refPx[i + 1]) + (curPx[i + 2] - refPx[i + 2]);
+                if (brighter > brightThresh)
+                    mask[y * w + x] = true;
+            }
+        });
+
+        // Find connected clusters via row-scan: collect bounding boxes of bright regions
+        var boxes = FindBrightClusters(mask, w, h, minWidth: 40, minHeight: 10, maxGap: 8);
+        Log.Information("NameplateDiff: found {Count} bright clusters", boxes.Count);
+
+        if (boxes.Count == 0)
+            return Task.FromResult(new OcrResponse { Text = "", Lines = [] });
+
+        // OCR each cluster crop, accumulate results with screen-space coordinates
+        var allLines = new List<OcrLine>();
+        var allText = new List<string>();
+
+        foreach (var box in boxes)
+        {
+            // Pad the crop slightly
+            int pad = 4;
+            int cx = Math.Max(0, box.X - pad);
+            int cy = Math.Max(0, box.Y - pad);
+            int cw = Math.Min(w - cx, box.Width + pad * 2);
+            int ch = Math.Min(h - cy, box.Height + pad * 2);
+
+            using var crop = current.Clone(new Rectangle(cx, cy, cw, ch), PixelFormat.Format32bppArgb);
+            var ocrResult = _pythonBridge.OcrFromBitmap(crop);
+
+            // Offset word coordinates to screen space
+            foreach (var line in ocrResult.Lines)
+            {
+                foreach (var word in line.Words)
+                {
+                    word.X += cx;
+                    word.Y += cy;
+                }
+                allLines.Add(line);
+                allText.Add(line.Text);
+            }
+        }
+
+        return Task.FromResult(new OcrResponse
+        {
+            Text = string.Join("\n", allText),
+            Lines = allLines,
+        });
+    }
+
+    private static List<Rectangle> FindBrightClusters(bool[] mask, int w, int h, int minWidth, int minHeight, int maxGap)
+    {
+        // Row density
+        int[] rowCounts = new int[h];
+        for (int y = 0; y < h; y++)
+            for (int x = 0; x < w; x++)
+                if (mask[y * w + x]) rowCounts[y]++;
+
+        // Find horizontal bands of bright rows
+        int rowThresh = 3;
+        var bands = new List<(int Top, int Bottom)>();
+        int bandStart = -1, lastActive = -1;
+        for (int y = 0; y < h; y++)
+        {
+            if (rowCounts[y] >= rowThresh)
+            {
+                if (bandStart < 0) bandStart = y;
+                lastActive = y;
+            }
+            else if (bandStart >= 0 && y - lastActive > maxGap)
+            {
+                if (lastActive - bandStart + 1 >= minHeight)
+                    bands.Add((bandStart, lastActive));
+                bandStart = -1;
+            }
+        }
+        if (bandStart >= 0 && lastActive - bandStart + 1 >= minHeight)
+            bands.Add((bandStart, lastActive));
+
+        // For each band, find column extents to get individual nameplate boxes
+        var boxes = new List<Rectangle>();
+        foreach (var (top, bottom) in bands)
+        {
+            int[] colCounts = new int[w];
+            for (int y = top; y <= bottom; y++)
+                for (int x = 0; x < w; x++)
+                    if (mask[y * w + x]) colCounts[x]++;
+
+            int colThresh = 1;
+            int colStart = -1, lastCol = -1;
+            for (int x = 0; x < w; x++)
+            {
+                if (colCounts[x] >= colThresh)
+                {
+                    if (colStart < 0) colStart = x;
+                    lastCol = x;
+                }
+                else if (colStart >= 0 && x - lastCol > maxGap)
+                {
+                    if (lastCol - colStart + 1 >= minWidth)
+                        boxes.Add(new Rectangle(colStart, top, lastCol - colStart + 1, bottom - top + 1));
+                    colStart = -1;
+                }
+            }
+            if (colStart >= 0 && lastCol - colStart + 1 >= minWidth)
+                boxes.Add(new Rectangle(colStart, top, lastCol - colStart + 1, bottom - top + 1));
+        }
+
+        return boxes;
+    }
+
     public void Dispose() => _pythonBridge.Dispose();
 
     // -- OCR text matching --