单目3D初始代码

ultralytics/models/yolo/world/train.py

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+# Ultralytics 🚀 AGPL-3.0 License - https://ultralytics.com/license
+
+from __future__ import annotations
+
+import itertools
+from pathlib import Path
+from typing import Any
+
+import torch
+
+from ultralytics.data import build_yolo_dataset
+from ultralytics.models.yolo.detect import DetectionTrainer
+from ultralytics.nn.tasks import WorldModel
+from ultralytics.utils import DEFAULT_CFG, LOGGER, RANK
+from ultralytics.utils.torch_utils import unwrap_model
+
+
+def on_pretrain_routine_end(trainer) -> None:
+    """Set up model classes and text encoder at the end of the pretrain routine."""
+    if RANK in {-1, 0}:
+        # Set class names for evaluation
+        names = [name.split("/", 1)[0] for name in list(trainer.test_loader.dataset.data["names"].values())]
+        unwrap_model(trainer.ema.ema).set_classes(names, cache_clip_model=False)
+
+
+class WorldTrainer(DetectionTrainer):
+    """A trainer class for fine-tuning YOLO World models on close-set datasets.
+
+    This trainer extends the DetectionTrainer to support training YOLO World models, which combine visual and textual
+    features for improved object detection and understanding. It handles text embedding generation and caching to
+    accelerate training with multi-modal data.
+
+    Attributes:
+        text_embeddings (dict[str, torch.Tensor] | None): Cached text embeddings for category names to accelerate
+            training.
+        model (WorldModel): The YOLO World model being trained.
+        data (dict[str, Any]): Dataset configuration containing class information.
+        args (Any): Training arguments and configuration.
+
+    Methods:
+        get_model: Return WorldModel initialized with specified config and weights.
+        build_dataset: Build YOLO Dataset for training or validation.
+        set_text_embeddings: Set text embeddings for datasets to accelerate training.
+        generate_text_embeddings: Generate text embeddings for a list of text samples.
+        preprocess_batch: Preprocess a batch of images and text for YOLOWorld training.
+
+    Examples:
+        Initialize and train a YOLO World model
+        >>> from ultralytics.models.yolo.world import WorldTrainer
+        >>> args = dict(model="yolov8s-world.pt", data="coco8.yaml", epochs=3)
+        >>> trainer = WorldTrainer(overrides=args)
+        >>> trainer.train()
+    """
+
+    def __init__(self, cfg=DEFAULT_CFG, overrides: dict[str, Any] | None = None, _callbacks=None):
+        """Initialize a WorldTrainer object with given arguments.
+
+        Args:
+            cfg (dict[str, Any]): Configuration for the trainer.
+            overrides (dict[str, Any], optional): Configuration overrides.
+            _callbacks (list[Any], optional): List of callback functions.
+        """
+        if overrides is None:
+            overrides = {}
+        assert not overrides.get("compile"), f"Training with 'model={overrides['model']}' requires 'compile=False'"
+        super().__init__(cfg, overrides, _callbacks)
+        self.text_embeddings = None
+
+    def get_model(self, cfg=None, weights: str | None = None, verbose: bool = True) -> WorldModel:
+        """Return WorldModel initialized with specified config and weights.
+
+        Args:
+            cfg (dict[str, Any] | str, optional): Model configuration.
+            weights (str, optional): Path to pretrained weights.
+            verbose (bool): Whether to display model info.
+
+        Returns:
+            (WorldModel): Initialized WorldModel.
+        """
+        # NOTE: This `nc` here is the max number of different text samples in one image, rather than the actual `nc`.
+        # NOTE: Following the official config, nc hard-coded to 80 for now.
+        model = WorldModel(
+            cfg["yaml_file"] if isinstance(cfg, dict) else cfg,
+            ch=self.data["channels"],
+            nc=min(self.data["nc"], 80),
+            verbose=verbose and RANK == -1,
+        )
+        if weights:
+            model.load(weights)
+        self.add_callback("on_pretrain_routine_end", on_pretrain_routine_end)
+
+        return model
+
+    def build_dataset(self, img_path: str, mode: str = "train", batch: int | None = None):
+        """Build YOLO Dataset for training or validation.
+
+        Args:
+            img_path (str): Path to the folder containing images.
+            mode (str): `train` mode or `val` mode, users are able to customize different augmentations for each mode.
+            batch (int, optional): Size of batches, this is for `rect`.
+
+        Returns:
+            (Any): YOLO dataset configured for training or validation.
+        """
+        gs = max(int(unwrap_model(self.model).stride.max() if self.model else 0), 32)
+        dataset = build_yolo_dataset(
+            self.args, img_path, batch, self.data, mode=mode, rect=mode == "val", stride=gs, multi_modal=mode == "train"
+        )
+        if mode == "train":
+            self.set_text_embeddings([dataset], batch)  # cache text embeddings to accelerate training
+        return dataset
+
+    def set_text_embeddings(self, datasets: list[Any], batch: int | None) -> None:
+        """Set text embeddings for datasets to accelerate training by caching category names.
+
+        This method collects unique category names from all datasets, then generates and caches text embeddings for
+        these categories to improve training efficiency.
+
+        Args:
+            datasets (list[Any]): List of datasets from which to extract category names.
+            batch (int | None): Batch size used for processing.
+
+        Notes:
+            This method collects category names from datasets that have the 'category_names' attribute,
+            then uses the first dataset's image path to determine where to cache the generated text embeddings.
+        """
+        text_embeddings = {}
+        for dataset in datasets:
+            if not hasattr(dataset, "category_names"):
+                continue
+            text_embeddings.update(
+                self.generate_text_embeddings(
+                    list(dataset.category_names), batch, cache_dir=Path(dataset.img_path).parent
+                )
+            )
+        self.text_embeddings = text_embeddings
+
+    def generate_text_embeddings(self, texts: list[str], batch: int, cache_dir: Path) -> dict[str, torch.Tensor]:
+        """Generate text embeddings for a list of text samples.
+
+        Args:
+            texts (list[str]): List of text samples to encode.
+            batch (int): Batch size for processing.
+            cache_dir (Path): Directory to save/load cached embeddings.
+
+        Returns:
+            (dict[str, torch.Tensor]): Dictionary mapping text samples to their embeddings.
+        """
+        model = "clip:ViT-B/32"
+        cache_path = cache_dir / f"text_embeddings_{model.replace(':', '_').replace('/', '_')}.pt"
+        if cache_path.exists():
+            LOGGER.info(f"Reading existed cache from '{cache_path}'")
+            txt_map = torch.load(cache_path, map_location=self.device)
+            if sorted(txt_map.keys()) == sorted(texts):
+                return txt_map
+        LOGGER.info(f"Caching text embeddings to '{cache_path}'")
+        assert self.model is not None
+        txt_feats = unwrap_model(self.model).get_text_pe(texts, batch, cache_clip_model=False)
+        txt_map = dict(zip(texts, txt_feats.squeeze(0)))
+        torch.save(txt_map, cache_path)
+        return txt_map
+
+    def preprocess_batch(self, batch: dict[str, Any]) -> dict[str, Any]:
+        """Preprocess a batch of images and text for YOLOWorld training."""
+        batch = DetectionTrainer.preprocess_batch(self, batch)
+
+        # Add text features
+        texts = list(itertools.chain(*batch["texts"]))
+        txt_feats = torch.stack([self.text_embeddings[text] for text in texts]).to(
+            self.device, non_blocking=self.device.type == "cuda"
+        )
+        batch["txt_feats"] = txt_feats.reshape(len(batch["texts"]), -1, txt_feats.shape[-1])
+        return batch