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Resume/ultralytics/models/yolo/segment/val.py
2025-11-08 19:15:39 +01:00

260 lines
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Python

# Ultralytics 🚀 AGPL-3.0 License - https://ultralytics.com/license
from __future__ import annotations
from multiprocessing.pool import ThreadPool
from pathlib import Path
from typing import Any
import numpy as np
import torch
import torch.nn.functional as F
from ultralytics.models.yolo.detect import DetectionValidator
from ultralytics.utils import LOGGER, NUM_THREADS, ops
from ultralytics.utils.checks import check_requirements
from ultralytics.utils.metrics import SegmentMetrics, mask_iou
class SegmentationValidator(DetectionValidator):
"""
A class extending the DetectionValidator class for validation based on a segmentation model.
This validator handles the evaluation of segmentation models, processing both bounding box and mask predictions
to compute metrics such as mAP for both detection and segmentation tasks.
Attributes:
plot_masks (list): List to store masks for plotting.
process (callable): Function to process masks based on save_json and save_txt flags.
args (namespace): Arguments for the validator.
metrics (SegmentMetrics): Metrics calculator for segmentation tasks.
stats (dict): Dictionary to store statistics during validation.
Examples:
>>> from ultralytics.models.yolo.segment import SegmentationValidator
>>> args = dict(model="yolo11n-seg.pt", data="coco8-seg.yaml")
>>> validator = SegmentationValidator(args=args)
>>> validator()
"""
def __init__(self, dataloader=None, save_dir=None, args=None, _callbacks=None) -> None:
"""
Initialize SegmentationValidator and set task to 'segment', metrics to SegmentMetrics.
Args:
dataloader (torch.utils.data.DataLoader, optional): Dataloader to use for validation.
save_dir (Path, optional): Directory to save results.
args (namespace, optional): Arguments for the validator.
_callbacks (list, optional): List of callback functions.
"""
super().__init__(dataloader, save_dir, args, _callbacks)
self.process = None
self.args.task = "segment"
self.metrics = SegmentMetrics()
def preprocess(self, batch: dict[str, Any]) -> dict[str, Any]:
"""
Preprocess batch of images for YOLO segmentation validation.
Args:
batch (dict[str, Any]): Batch containing images and annotations.
Returns:
(dict[str, Any]): Preprocessed batch.
"""
batch = super().preprocess(batch)
batch["masks"] = batch["masks"].float()
return batch
def init_metrics(self, model: torch.nn.Module) -> None:
"""
Initialize metrics and select mask processing function based on save_json flag.
Args:
model (torch.nn.Module): Model to validate.
"""
super().init_metrics(model)
if self.args.save_json:
check_requirements("faster-coco-eval>=1.6.7")
# More accurate vs faster
self.process = ops.process_mask_native if self.args.save_json or self.args.save_txt else ops.process_mask
def get_desc(self) -> str:
"""Return a formatted description of evaluation metrics."""
return ("%22s" + "%11s" * 10) % (
"Class",
"Images",
"Instances",
"Box(P",
"R",
"mAP50",
"mAP50-95)",
"Mask(P",
"R",
"mAP50",
"mAP50-95)",
)
def postprocess(self, preds: list[torch.Tensor]) -> list[dict[str, torch.Tensor]]:
"""
Post-process YOLO predictions and return output detections with proto.
Args:
preds (list[torch.Tensor]): Raw predictions from the model.
Returns:
list[dict[str, torch.Tensor]]: Processed detection predictions with masks.
"""
proto = preds[1][-1] if len(preds[1]) == 3 else preds[1] # second output is len 3 if pt, but only 1 if exported
preds = super().postprocess(preds[0])
imgsz = [4 * x for x in proto.shape[2:]] # get image size from proto
for i, pred in enumerate(preds):
coefficient = pred.pop("extra")
pred["masks"] = (
self.process(proto[i], coefficient, pred["bboxes"], shape=imgsz)
if coefficient.shape[0]
else torch.zeros(
(0, *(imgsz if self.process is ops.process_mask_native else proto.shape[2:])),
dtype=torch.uint8,
device=pred["bboxes"].device,
)
)
return preds
def _prepare_batch(self, si: int, batch: dict[str, Any]) -> dict[str, Any]:
"""
Prepare a batch for training or inference by processing images and targets.
Args:
si (int): Batch index.
batch (dict[str, Any]): Batch data containing images and annotations.
Returns:
(dict[str, Any]): Prepared batch with processed annotations.
"""
prepared_batch = super()._prepare_batch(si, batch)
nl = prepared_batch["cls"].shape[0]
if self.args.overlap_mask:
masks = batch["masks"][si]
index = torch.arange(1, nl + 1, device=masks.device).view(nl, 1, 1)
masks = (masks == index).float()
else:
masks = batch["masks"][batch["batch_idx"] == si]
if nl:
mask_size = [s if self.process is ops.process_mask_native else s // 4 for s in prepared_batch["imgsz"]]
if masks.shape[1:] != mask_size:
masks = F.interpolate(masks[None], mask_size, mode="bilinear", align_corners=False)[0]
masks = masks.gt_(0.5)
prepared_batch["masks"] = masks
return prepared_batch
def _process_batch(self, preds: dict[str, torch.Tensor], batch: dict[str, Any]) -> dict[str, np.ndarray]:
"""
Compute correct prediction matrix for a batch based on bounding boxes and optional masks.
Args:
preds (dict[str, torch.Tensor]): Dictionary containing predictions with keys like 'cls' and 'masks'.
batch (dict[str, Any]): Dictionary containing batch data with keys like 'cls' and 'masks'.
Returns:
(dict[str, np.ndarray]): A dictionary containing correct prediction matrices including 'tp_m' for mask IoU.
Notes:
- If `masks` is True, the function computes IoU between predicted and ground truth masks.
- If `overlap` is True and `masks` is True, overlapping masks are taken into account when computing IoU.
Examples:
>>> preds = {"cls": torch.tensor([1, 0]), "masks": torch.rand(2, 640, 640), "bboxes": torch.rand(2, 4)}
>>> batch = {"cls": torch.tensor([1, 0]), "masks": torch.rand(2, 640, 640), "bboxes": torch.rand(2, 4)}
>>> correct_preds = validator._process_batch(preds, batch)
"""
tp = super()._process_batch(preds, batch)
gt_cls = batch["cls"]
if gt_cls.shape[0] == 0 or preds["cls"].shape[0] == 0:
tp_m = np.zeros((preds["cls"].shape[0], self.niou), dtype=bool)
else:
iou = mask_iou(batch["masks"].flatten(1), preds["masks"].flatten(1))
tp_m = self.match_predictions(preds["cls"], gt_cls, iou).cpu().numpy()
tp.update({"tp_m": tp_m}) # update tp with mask IoU
return tp
def plot_predictions(self, batch: dict[str, Any], preds: list[dict[str, torch.Tensor]], ni: int) -> None:
"""
Plot batch predictions with masks and bounding boxes.
Args:
batch (dict[str, Any]): Batch containing images and annotations.
preds (list[dict[str, torch.Tensor]]): List of predictions from the model.
ni (int): Batch index.
"""
for p in preds:
masks = p["masks"]
if masks.shape[0] > self.args.max_det:
LOGGER.warning(f"Limiting validation plots to 'max_det={self.args.max_det}' items.")
p["masks"] = torch.as_tensor(masks[: self.args.max_det], dtype=torch.uint8).cpu()
super().plot_predictions(batch, preds, ni, max_det=self.args.max_det) # plot bboxes
def save_one_txt(self, predn: torch.Tensor, save_conf: bool, shape: tuple[int, int], file: Path) -> None:
"""
Save YOLO detections to a txt file in normalized coordinates in a specific format.
Args:
predn (torch.Tensor): Predictions in the format (x1, y1, x2, y2, conf, class).
save_conf (bool): Whether to save confidence scores.
shape (tuple[int, int]): Shape of the original image.
file (Path): File path to save the detections.
"""
from ultralytics.engine.results import Results
Results(
np.zeros((shape[0], shape[1]), dtype=np.uint8),
path=None,
names=self.names,
boxes=torch.cat([predn["bboxes"], predn["conf"].unsqueeze(-1), predn["cls"].unsqueeze(-1)], dim=1),
masks=torch.as_tensor(predn["masks"], dtype=torch.uint8),
).save_txt(file, save_conf=save_conf)
def pred_to_json(self, predn: dict[str, torch.Tensor], pbatch: dict[str, Any]) -> None:
"""
Save one JSON result for COCO evaluation.
Args:
predn (dict[str, torch.Tensor]): Predictions containing bboxes, masks, confidence scores, and classes.
pbatch (dict[str, Any]): Batch dictionary containing 'imgsz', 'ori_shape', 'ratio_pad', and 'im_file'.
"""
from faster_coco_eval.core.mask import encode # noqa
def single_encode(x):
"""Encode predicted masks as RLE and append results to jdict."""
rle = encode(np.asarray(x[:, :, None], order="F", dtype="uint8"))[0]
rle["counts"] = rle["counts"].decode("utf-8")
return rle
pred_masks = np.transpose(predn["masks"], (2, 0, 1))
with ThreadPool(NUM_THREADS) as pool:
rles = pool.map(single_encode, pred_masks)
super().pred_to_json(predn, pbatch)
for i, r in enumerate(rles):
self.jdict[-len(rles) + i]["segmentation"] = r # segmentation
def scale_preds(self, predn: dict[str, torch.Tensor], pbatch: dict[str, Any]) -> dict[str, torch.Tensor]:
"""Scales predictions to the original image size."""
return {
**super().scale_preds(predn, pbatch),
"masks": ops.scale_image(
torch.as_tensor(predn["masks"], dtype=torch.uint8).permute(1, 2, 0).contiguous().cpu().numpy(),
pbatch["ori_shape"],
ratio_pad=pbatch["ratio_pad"],
),
}
def eval_json(self, stats: dict[str, Any]) -> dict[str, Any]:
"""Return COCO-style instance segmentation evaluation metrics."""
pred_json = self.save_dir / "predictions.json" # predictions
anno_json = (
self.data["path"]
/ "annotations"
/ ("instances_val2017.json" if self.is_coco else f"lvis_v1_{self.args.split}.json")
) # annotations
return super().coco_evaluate(stats, pred_json, anno_json, ["bbox", "segm"], suffix=["Box", "Mask"])