feat(detect): 推理侧改为切片,与固定 160 输入一致

训练数据已经是固定边长的片,推理还把整图交给 ultralytics 就会被 letterbox 缩放,
与模型见过的形态不符。三个调用方(可视化、批量推送预测、ML backend)统一改成
切片推理再拼回原图。

- engine/tiling.merge_tiles / tiled_predict:映射回原图、裁掉镜像填充区的框、跨片去重。
  推理框架留在调用方,几何部分可单测。
- engine/detection.nms:标准 NMS,另加按包含比例抑制。缺陷被切割线切开时,相邻片
  只看到一角,给出的小残框与完整框 IoU 很小(面积悬殊),光靠 IoU 压不掉。
- engine/tiled_inference:ultralytics 的接线,内部分批,避免片数多时 OOM。
- 三处调用点加 --tile-size / --tile-overlap(后端为 YOLO_TILE_SIZE / YOLO_TILE_OVERLAP),
  默认 160 / 32;设 0 退回整图推理,仅用于和旧模型对比。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
Shaun Zhou
2026-09-23 15:12:35 +08:00
co-authored by Claude Opus 5
parent 2a92275317
commit 474b7b50a0
9 changed files with 412 additions and 75 deletions
+47
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@@ -102,6 +102,53 @@ def match_boxes(
)
def containment(inner: Box, outer: Box) -> float:
"""inner 有多大比例落在 outer 里(0~1)。面积悬殊时 IoU 会很小,但这个值接近 1。"""
left, top = max(inner.x1, outer.x1), max(inner.y1, outer.y1)
right, bottom = min(inner.x2, outer.x2), min(inner.y2, outer.y2)
if right <= left or bottom <= top:
return 0.0
area = max(inner.x2 - inner.x1, 0) * max(inner.y2 - inner.y1, 0)
return (right - left) * (bottom - top) / area if area > 0 else 0.0
def nms(
boxes: Sequence[Box],
iou_threshold: float = 0.5,
per_class: bool = True,
contained_threshold: float = 0.0,
) -> list[int]:
"""非极大值抑制,返回保留下来的下标(按输入顺序)。
用于把切片推理的结果拼回整图:相邻片在重叠区会把同一处缺陷各检出一次,
合并后必须去重。注意这与"禁止框重叠"是两回事——这里只压掉重复,
真正分开的两个缺陷即使轻微相邻也都保留。
Args:
per_class: 只在同类之间抑制。不同类别的框重叠往往是有意义的分歧,不该互相压制。
contained_threshold: 额外按**包含比例**抑制,0 = 关闭。切片时缺陷被切割线切开,
相邻片只看到一角,会给出一个小残框;它与完整框的 IoU 很小(面积悬殊),
光靠 IoU 压不掉,但它几乎完全落在完整框里。
"""
order = sorted(range(len(boxes)), key=lambda i: -(boxes[i].score or 0.0))
kept: list[int] = []
for index in order:
box = boxes[index]
duplicate = False
for other in kept:
if per_class and boxes[other].class_id != box.class_id:
continue
if iou(box, boxes[other]) > iou_threshold:
duplicate = True
break
if contained_threshold and containment(box, boxes[other]) >= contained_threshold:
duplicate = True
break
if not duplicate:
kept.append(index)
return sorted(kept)
def draw_boxes(image, ground_truth: Sequence[Box], predictions: Sequence[Box],
classes: Sequence[str], match: Match, width: int = 2):
"""把真值与预测画在图上(就地修改传入的 PIL 图像并返回)。
+85
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@@ -0,0 +1,85 @@
"""用 ultralytics 做切片推理的公共封装。
三个调用方(可视化、批量推送预测、ML backend)都要"切片 -> 逐片推理 -> 拼回原图",
逻辑一致,放在一处免得各写一份走样。
几何在 `engine.tiling` 里,与推理框架无关且单独可测;这里只负责把 ultralytics 接上去。
"""
from __future__ import annotations
from collections.abc import Sequence
import numpy as np
from engine.detection import Box
from engine.tiling import tiled_predict
def predict_image(
model,
image: np.ndarray,
size: int,
overlap: int = 0,
conf: float = 0.25,
device: str | int = "cpu",
batch: int = 16,
iou_threshold: float = 0.5,
whole_image_imgsz: int | None = None,
) -> list[Box]:
"""对一张任意尺寸的图做切片推理,返回整图上的归一化框。
`size <= 0` 时退化为整图推理,交给 ultralytics 按 `whole_image_imgsz` 做 letterbox
——那会缩放,只用于和旧模型对比。
"""
if size <= 0:
return _predict_batch(
model, [image], whole_image_imgsz, conf=conf, device=device, batch=batch
)[0]
def run(patches: Sequence[np.ndarray]) -> list[list[Box]]:
return _predict_batch(model, patches, size, conf, device, batch)
return tiled_predict(run, image, size, overlap, iou_threshold)
def _predict_batch(
model,
images: Sequence[np.ndarray],
size: int | None,
conf: float,
device: str | int,
batch: int,
) -> list[list[Box]]:
"""分批送进 ultralytics,返回每张图的归一化框。
必须自己分批:ultralytics 不理会 batch 参数,会把整个列表当成一个 batch,
片数一多就会撑爆显存。
"""
results = []
for start in range(0, len(images), batch):
chunk = list(images[start:start + batch])
kwargs = {"conf": conf, "device": device, "verbose": False}
if size:
kwargs["imgsz"] = size
results.extend(model.predict(source=chunk, **kwargs))
out = []
for result in results:
out.append([
Box(int(class_id), *(float(v) for v in xyxyn), float(score))
for xyxyn, class_id, score in zip(
result.boxes.xyxyn.tolist(), result.boxes.cls.tolist(),
result.boxes.conf.tolist(), strict=True,
)
])
return out
def load_image(path) -> np.ndarray:
"""读图为 numpy 数组,保持原始通道数(灰度图不强行转 RGB,免得多占三倍内存)。"""
from PIL import Image
with Image.open(path) as handle:
image = handle.convert("L") if handle.mode in ("L", "1", "I;16") else handle.convert("RGB")
return np.asarray(image)
+59
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@@ -132,6 +132,65 @@ def remap_boxes(
return kept
def merge_tiles(
per_tile: Sequence[Sequence[Box]],
tiles: Sequence[Tile],
size: int,
width: int,
height: int,
iou_threshold: float = 0.5,
contained_threshold: float = 0.8,
) -> list[Box]:
"""把每片各自的框拼回整图,返回相对原图归一化的框。
三步:映射回原图像素 → 裁掉落在镜像填充区里的部分(那里是复制品,不是真实区域)
→ 跨片去重。
去重同时看 IoU 与包含比例:缺陷被切割线切开时,相邻片只看到一角,给出的小残框
与完整框的 IoU 很小(面积悬殊),但几乎整个落在完整框里。只看 IoU 会把残框留下来。
残框与完整框互不包含的情况(缺陷正好被切成两半、两片各见一半)只能靠 `overlap`
避免——重叠大于缺陷尺寸时,总有一片能完整看到它。
"""
from engine.detection import nms
collected = []
for tile, boxes in zip(tiles, per_tile, strict=True):
for box in boxes:
mapped = to_source(box, tile, size)
x1, y1 = max(mapped.x1, 0.0), max(mapped.y1, 0.0)
x2, y2 = min(mapped.x2, float(width)), min(mapped.y2, float(height))
if x2 <= x1 or y2 <= y1:
continue
collected.append(
Box(box.class_id, x1 / width, y1 / height, x2 / width, y2 / height, box.score)
)
return [
collected[i]
for i in nms(collected, iou_threshold, contained_threshold=contained_threshold)
]
def tiled_predict(
predict_batch,
image: np.ndarray,
size: int,
overlap: int = 0,
iou_threshold: float = 0.5,
) -> list[Box]:
"""按固定边长切片推理再拼回,返回整图上的归一化框。
Args:
predict_batch: 接收一批 `size × size` 的图、返回每张图的归一化框列表。
推理框架留在调用方,这里只管几何,便于单测。
image: HxW 或 HxWxC 的原图。
"""
height, width = image.shape[:2]
tiles = plan_tiles(width, height, size, overlap)
patches = [cut(image, tile, size) for tile in tiles]
return merge_tiles(predict_batch(patches), tiles, size, width, height, iou_threshold)
def to_source(box: Box, tile: Tile, size: int) -> Box:
"""反向:把片上的归一化框映射回原图的**像素** xyxy。