Refactor val code into new `self.match_predictions()` method (#4265)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

ultralytics/engine/validator.py

@@ -22,6 +22,7 @@ import json
 import time
 from pathlib import Path
 
+import numpy as np
 import torch
 from tqdm import tqdm
 
@@ -199,6 +200,33 @@ class BaseValidator:
                 LOGGER.info(f"Results saved to {colorstr('bold', self.save_dir)}")
             return stats
 
+    def match_predictions(self, pred_classes: torch.Tensor, true_classes: torch.Tensor,
+                          iou: torch.Tensor) -> torch.Tensor:
+        """
+        Matches predictions to ground truth objects (pred_classes, true_classes) using IoU.
+
+        Args:
+            pred_classes (torch.Tensor): Predicted class indices of shape(N,).
+            true_classes (torch.Tensor): Target class indices of shape(M,).
+
+        Returns:
+            (torch.Tensor): Correct tensor of shape(N,10) for 10 IoU thresholds.
+        """
+        correct = np.zeros((pred_classes.shape[0], self.iouv.shape[0])).astype(bool)
+        correct_class = true_classes[:, None] == pred_classes
+        for i in range(len(self.iouv)):
+            x = torch.where((iou >= self.iouv[i]) & correct_class)  # IoU > threshold and classes match
+            if x[0].shape[0]:
+                # Concatenate [label, detect, iou]
+                matches = torch.cat((torch.stack(x, 1), iou[x[0], x[1]][:, None]), 1).cpu().numpy()
+                if x[0].shape[0] > 1:
+                    matches = matches[matches[:, 2].argsort()[::-1]]
+                    matches = matches[np.unique(matches[:, 1], return_index=True)[1]]
+                    # matches = matches[matches[:, 2].argsort()[::-1]]
+                    matches = matches[np.unique(matches[:, 0], return_index=True)[1]]
+                correct[matches[:, 1].astype(int), i] = True
+        return torch.tensor(correct, dtype=torch.bool, device=pred_classes.device)
+
     def add_callback(self, event: str, callback):
         """Appends the given callback."""
         self.callbacks[event].append(callback)

ultralytics/models/fastsam/val.py

@@ -150,20 +150,7 @@ class FastSAMValidator(DetectionValidator):
         else:  # boxes
             iou = box_iou(labels[:, 1:], detections[:, :4])
 
-        correct = np.zeros((detections.shape[0], self.iouv.shape[0])).astype(bool)
-        correct_class = labels[:, 0:1] == detections[:, 5]
-        for i in range(len(self.iouv)):
-            x = torch.where((iou >= self.iouv[i]) & correct_class)  # IoU > threshold and classes match
-            if x[0].shape[0]:
-                matches = torch.cat((torch.stack(x, 1), iou[x[0], x[1]][:, None]),
-                                    1).cpu().numpy()  # [label, detect, iou]
-                if x[0].shape[0] > 1:
-                    matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 1], return_index=True)[1]]
-                    # matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 0], return_index=True)[1]]
-                correct[matches[:, 1].astype(int), i] = True
-        return torch.tensor(correct, dtype=torch.bool, device=detections.device)
+        return self.match_predictions(detections[:, 5], labels[:, 0], iou)
 
     def plot_val_samples(self, batch, ni):
         """Plots validation samples with bounding box labels."""

ultralytics/models/yolo/detect/val.py

@@ -163,20 +163,7 @@ class DetectionValidator(BaseValidator):
             correct (array[N, 10]), for 10 IoU levels
         """
         iou = box_iou(labels[:, 1:], detections[:, :4])
-        correct = np.zeros((detections.shape[0], self.iouv.shape[0])).astype(bool)
-        correct_class = labels[:, 0:1] == detections[:, 5]
-        for i in range(len(self.iouv)):
-            x = torch.where((iou >= self.iouv[i]) & correct_class)  # IoU > threshold and classes match
-            if x[0].shape[0]:
-                matches = torch.cat((torch.stack(x, 1), iou[x[0], x[1]][:, None]),
-                                    1).cpu().numpy()  # [label, detect, iou]
-                if x[0].shape[0] > 1:
-                    matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 1], return_index=True)[1]]
-                    # matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 0], return_index=True)[1]]
-                correct[matches[:, 1].astype(int), i] = True
-        return torch.tensor(correct, dtype=torch.bool, device=detections.device)
+        return self.match_predictions(detections[:, 5], labels[:, 0], iou)
 
     def build_dataset(self, img_path, mode='val', batch=None):
         """Build YOLO Dataset

ultralytics/models/yolo/pose/val.py

@@ -128,20 +128,7 @@ class PoseValidator(DetectionValidator):
         else:  # boxes
             iou = box_iou(labels[:, 1:], detections[:, :4])
 
-        correct = np.zeros((detections.shape[0], self.iouv.shape[0])).astype(bool)
-        correct_class = labels[:, 0:1] == detections[:, 5]
-        for i in range(len(self.iouv)):
-            x = torch.where((iou >= self.iouv[i]) & correct_class)  # IoU > threshold and classes match
-            if x[0].shape[0]:
-                matches = torch.cat((torch.stack(x, 1), iou[x[0], x[1]][:, None]),
-                                    1).cpu().numpy()  # [label, detect, iou]
-                if x[0].shape[0] > 1:
-                    matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 1], return_index=True)[1]]
-                    # matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 0], return_index=True)[1]]
-                correct[matches[:, 1].astype(int), i] = True
-        return torch.tensor(correct, dtype=torch.bool, device=detections.device)
+        return self.match_predictions(detections[:, 5], labels[:, 0], iou)
 
     def plot_val_samples(self, batch, ni):
         """Plots and saves validation set samples with predicted bounding boxes and keypoints."""

ultralytics/models/yolo/segment/val.py

@@ -150,20 +150,7 @@ class SegmentationValidator(DetectionValidator):
         else:  # boxes
             iou = box_iou(labels[:, 1:], detections[:, :4])
 
-        correct = np.zeros((detections.shape[0], self.iouv.shape[0])).astype(bool)
-        correct_class = labels[:, 0:1] == detections[:, 5]
-        for i in range(len(self.iouv)):
-            x = torch.where((iou >= self.iouv[i]) & correct_class)  # IoU > threshold and classes match
-            if x[0].shape[0]:
-                matches = torch.cat((torch.stack(x, 1), iou[x[0], x[1]][:, None]),
-                                    1).cpu().numpy()  # [label, detect, iou]
-                if x[0].shape[0] > 1:
-                    matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 1], return_index=True)[1]]
-                    # matches = matches[matches[:, 2].argsort()[::-1]]
-                    matches = matches[np.unique(matches[:, 0], return_index=True)[1]]
-                correct[matches[:, 1].astype(int), i] = True
-        return torch.tensor(correct, dtype=torch.bool, device=detections.device)
+        return self.match_predictions(detections[:, 5], labels[:, 0], iou)
 
     def plot_val_samples(self, batch, ni):
         """Plots validation samples with bounding box labels."""