From da0d2cf2eff3495a98d8a7437753bd1464482cd8 Mon Sep 17 00:00:00 2001
From: inter <inter@qq.com>
Date: Thu, 4 Sep 2025 14:08:56 +0800
Subject: [PATCH] Add File

---
 .../java/org/dromara/easyai/tools/NMS.java    | 118 ++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 src/main/java/org/dromara/easyai/tools/NMS.java

diff --git a/src/main/java/org/dromara/easyai/tools/NMS.java b/src/main/java/org/dromara/easyai/tools/NMS.java
new file mode 100644
index 0000000..93f5435
--- /dev/null
+++ b/src/main/java/org/dromara/easyai/tools/NMS.java
@@ -0,0 +1,118 @@
+package org.dromara.easyai.tools;
+
+import org.dromara.easyai.entity.Box;
+
+import java.util.*;
+
+/**
+ * @param
+ * @DATA
+ * @Author LiDaPeng
+ * @Description
+ */
+public class NMS {
+    private final float iouTh;//iou阈值
+
+    public NMS(float iouTh) {
+        this.iouTh = iouTh;
+    }
+
+    public List<Box> start(List<Box> pixelPositions) {
+        //先进行排序
+        if (pixelPositions.isEmpty()) {
+            return null;
+        }
+        List<Box> pixels = new ArrayList<>();
+        ConfidenceSort2 confidenceSort = new ConfidenceSort2();
+        pixelPositions.sort(confidenceSort);
+        screen(pixelPositions, pixels);
+        return pixels;
+    }
+
+    public float getSRatio(Box box1, Box box2, boolean first) {
+        IouMessage iouMessage = getMyIou(box1, box2);
+        if (first) {
+            return iouMessage.intersectS / iouMessage.s1;
+        }
+        return iouMessage.intersectS / iouMessage.s2;
+    }
+
+    private IouMessage getMyIou(Box box1, Box box2) {
+        int minX1 = box1.getX();
+        int minY1 = box1.getY();
+        int maxX1 = minX1 + box1.getxSize();
+        int maxY1 = minY1 + box1.getySize();
+        float s1 = box1.getxSize() * box1.getySize();
+        int minX2 = box2.getX();
+        int minY2 = box2.getY();
+        int maxX2 = minX2 + box2.getxSize();
+        int maxY2 = minY2 + box2.getySize();
+        float s2 = box2.getxSize() * box2.getySize();
+        float[] row = new float[]{minX1, maxX1, minX2, maxX2};
+        float[] col = new float[]{minY1, maxY1, minY2, maxY2};
+        Arrays.sort(row);
+        Arrays.sort(col);
+        float rowSub = row[3] - row[0];
+        float colSub = col[3] - col[0];
+        float width = box1.getySize() + box2.getySize();
+        float height = box1.getxSize() + box2.getxSize();
+        float widthSub = width - colSub;
+        float heightSub = height - rowSub;
+        if (widthSub < 0) {
+            widthSub = 0;
+        }
+        if (heightSub < 0) {
+            heightSub = 0;
+        }
+        IouMessage iouMessage = new IouMessage();
+        iouMessage.intersectS = widthSub * heightSub;
+        iouMessage.s1 = s1;
+        iouMessage.s2 = s2;
+        return iouMessage;
+    }
+
+    private boolean isOne(Box box1, Box box2, float iouTh) {
+        boolean isOne = false;
+        IouMessage iouMessage = getMyIou(box1, box2);
+        float mergeS = iouMessage.s1 + iouMessage.s2 - iouMessage.intersectS;
+        float iou = iouMessage.intersectS / mergeS;
+        if (iou > iouTh) {
+            isOne = true;
+        }
+        return isOne;
+    }
+
+    private void screen(List<Box> pixelPositions, List<Box> boxes) {
+        do {
+            Box maxPixelPosition = pixelPositions.get(0);
+            boxes.add(maxPixelPosition);
+            pixelPositions.remove(0);
+            for (int i = 0; i < pixelPositions.size(); i++) {
+                Box box = pixelPositions.get(i);
+                if (isOne(maxPixelPosition, box, iouTh)) {//要移除
+                    pixelPositions.remove(i);
+                    i--;
+                }
+            }
+        } while (pixelPositions.size() > 0);
+    }
+
+    static class ConfidenceSort2 implements Comparator<Box> {
+
+        @Override
+        public int compare(Box o1, Box o2) {
+            if (o1.getConfidence() > o2.getConfidence()) {
+                return -1;
+            } else if (o1.getConfidence() < o2.getConfidence()) {
+                return 1;
+            }
+            return 0;
+        }
+    }
+
+    static class IouMessage {
+        float intersectS;
+        float s1;
+        float s2;
+    }
+}