Files
ModelTrainEval/tests/test_detection.py
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Shaun ZhouandClaude Opus 5 eba533a5b2 feat(detect): 约束预测框互不重叠
人工标注的真值里一处缺陷只有一个框:11211 张图、151 张多框图,重叠框对为 0。
而模型预测在验证集上有 6.9% 的图存在重叠框——NMS 只在同类内、按固定 IoU 阈值抑制,
压不掉两类情况:同一处缺陷被两个类别各框一次(实测 IoU 高达 0.99),以及 IoU 低于
NMS 阈值的同类重叠(grease 66 对、wrinkle 45 对)。

- engine/detection.suppress_overlaps:按置信度贪心保留互不重叠的框,可设允许的
  最大 IoU;另可丢弃被大框完全包住的小框(面积悬殊时 IoU 很小,但显然是重复表达)。
- visualize_detections 默认 --max-overlap 0(与真值一致),并放出 --nms-iou 与
  类别无关 NMS 开关;--max-overlap -1 可看模型原始输出。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-18 11:19:47 +08:00

193 lines
6.6 KiB
Python

"""检测结果的匹配与绘制。"""
import pytest
pytest.importorskip("PIL")
from engine.detection import ( # noqa: E402
COLOR_GT,
COLOR_MATCHED,
COLOR_UNMATCHED,
Box,
draw_boxes,
from_yolo,
iou,
match_boxes,
parse_label,
suppress_overlaps,
)
def test_from_yolo_converts_center_to_corners():
assert from_yolo(2, 0.5, 0.5, 0.2, 0.4) == Box(2, 0.4, 0.3, 0.6, 0.7)
def test_parse_label_reads_boxes_and_empty_files():
boxes = parse_label("0 0.5 0.5 0.2 0.2\n3 0.1 0.1 0.1 0.1\n")
assert [b.class_id for b in boxes] == [0, 3]
assert parse_label("") == [] # 负样本
assert parse_label("\n\n") == []
@pytest.mark.parametrize(
"a,b,expected",
[
((0, 0, 1, 1), (0, 0, 1, 1), 1.0), # 完全重合
((0, 0, 1, 1), (2, 2, 3, 3), 0.0), # 不相交
((0, 0, 1, 1), (1, 1, 2, 2), 0.0), # 只碰到角
((0, 0, 2, 2), (1, 1, 3, 3), 1 / 7), # 交 1,并 7
],
)
def test_iou(a, b, expected):
assert iou(Box(0, *a), Box(0, *b)) == pytest.approx(expected)
def test_matches_by_confidence_first():
"""两个预测抢同一个真值时,置信度高的赢——与 mAP 的规则一致。"""
truth = [from_yolo(0, 0.5, 0.5, 0.2, 0.2)]
weak = Box(0, 0.4, 0.4, 0.6, 0.6, 0.3)
strong = Box(0, 0.41, 0.41, 0.59, 0.59, 0.9)
match = match_boxes([weak, strong], truth, iou_threshold=0.3)
assert match.pairs == [(1, 0)] # 下标 1 = strong
assert match.unmatched_predictions == [0]
assert match.unmatched_ground_truth == []
def test_low_iou_counts_as_both_miss_and_false_positive():
truth = [from_yolo(0, 0.2, 0.2, 0.1, 0.1)]
prediction = Box(0, 0.7, 0.7, 0.9, 0.9, 0.9)
match = match_boxes([prediction], truth)
assert match.pairs == []
assert match.unmatched_predictions == [0] # 误检
assert match.unmatched_ground_truth == [0] # 同时也是漏检
def test_class_mismatch_is_not_a_hit_unless_allowed():
"""定位准但分类错:默认不算命中,same_class=False 时可单看位置。"""
truth = [from_yolo(1, 0.5, 0.5, 0.2, 0.2)]
prediction = Box(0, 0.4, 0.4, 0.6, 0.6, 0.9)
assert match_boxes([prediction], truth).pairs == []
assert match_boxes([prediction], truth, same_class=False).pairs == [(0, 0)]
def test_each_ground_truth_is_claimed_once():
"""一个真值只能被一个预测认领,多出来的预测算误检。"""
truth = [from_yolo(0, 0.5, 0.5, 0.4, 0.4)]
predictions = [
Box(0, 0.31, 0.31, 0.69, 0.69, 0.9),
Box(0, 0.32, 0.32, 0.68, 0.68, 0.8),
]
match = match_boxes(predictions, truth)
assert len(match.pairs) == 1
assert len(match.unmatched_predictions) == 1
def test_no_prediction_on_background_is_clean():
match = match_boxes([], [])
assert match == ([], [], [])
def test_multiple_boxes_are_matched_pairwise():
truth = [from_yolo(0, 0.2, 0.2, 0.1, 0.1), from_yolo(1, 0.8, 0.8, 0.1, 0.1)]
predictions = [
Box(1, 0.75, 0.75, 0.85, 0.85, 0.7),
Box(0, 0.15, 0.15, 0.25, 0.25, 0.9),
]
match = match_boxes(predictions, truth)
assert sorted(match.pairs) == [(0, 1), (1, 0)]
assert not match.unmatched_predictions and not match.unmatched_ground_truth
def _colors(image):
return {pixel for pixel in image.getdata()}
def test_draw_uses_a_distinct_colour_per_role():
"""三种角色三种颜色:绿=真值,蓝=命中的预测,红=没对上的预测。"""
from PIL import Image
truth = [from_yolo(0, 0.25, 0.25, 0.2, 0.2), from_yolo(0, 0.75, 0.25, 0.2, 0.2)]
predictions = [
Box(0, 0.16, 0.16, 0.34, 0.34, 0.9), # 命中第一个
Box(0, 0.5, 0.8, 0.6, 0.9, 0.4), # 没有对应真值
]
match = match_boxes(predictions, truth, iou_threshold=0.5)
assert match.pairs == [(0, 0)]
image = Image.new("RGB", (200, 200), "black")
draw_boxes(image, truth, predictions, ["blackdot"], match)
present = _colors(image)
assert COLOR_GT in present and COLOR_MATCHED in present and COLOR_UNMATCHED in present
def test_draw_handles_boxes_at_the_border():
"""框贴着上边缘时,标签文字要画到框内,不能画到图外去。"""
from PIL import Image
image = Image.new("RGB", (64, 64), "black")
prediction = Box(0, 0.0, 0.0, 0.5, 0.05, 0.9)
draw_boxes(image, [], [prediction], ["blackdot"], match_boxes([prediction], []))
assert COLOR_UNMATCHED in _colors(image)
# ---------------- 不重叠约束 ----------------
def test_suppress_keeps_the_highest_score_of_an_overlapping_pair():
"""同一处缺陷被框两次时,留置信度高的那个。"""
strong = Box(0, 0.3, 0.3, 0.7, 0.7, 0.9)
weak = Box(1, 0.35, 0.35, 0.75, 0.75, 0.4)
assert suppress_overlaps([weak, strong]) == [1] # 下标 1 = strong
def test_suppress_is_cross_class():
"""NMS 只在同类内抑制;跨类重复要靠这一步。"""
a = Box(0, 0.3, 0.3, 0.7, 0.7, 0.9)
b = Box(5, 0.31, 0.31, 0.69, 0.69, 0.8)
assert suppress_overlaps([a, b]) == [0]
def test_suppress_keeps_disjoint_boxes():
"""真正分开的多个缺陷不能被误伤。"""
boxes = [
Box(0, 0.0, 0.0, 0.2, 0.2, 0.9),
Box(0, 0.5, 0.5, 0.7, 0.7, 0.8),
Box(1, 0.8, 0.1, 0.95, 0.3, 0.7),
]
assert suppress_overlaps(boxes) == [0, 1, 2]
def test_touching_edges_are_not_overlap():
"""边缘相接、面积不相交,IoU=0,应当都保留。"""
left = Box(0, 0.0, 0.0, 0.5, 1.0, 0.9)
right = Box(0, 0.5, 0.0, 1.0, 1.0, 0.8)
assert suppress_overlaps([left, right]) == [0, 1]
def test_contained_box_is_dropped_even_when_iou_is_below_the_threshold():
"""整图大框套一个小框:面积悬殊导致 IoU 很小,但显然是同一处目标的重复表达。
这正是 `contained` 的用武之地——只在允许轻微重叠(max_iou>0)时才有区别,
因为 max_iou=0 时任何包含都已经因 IoU>0 被抑制了。
"""
big = Box(0, 0.0, 0.0, 1.0, 1.0, 0.9)
small = Box(1, 0.45, 0.45, 0.55, 0.55, 0.8)
assert iou(big, small) < 0.02
assert suppress_overlaps([big, small], max_iou=0.1) == [0]
assert suppress_overlaps([big, small], max_iou=0.1, contained=False) == [0, 1]
def test_max_iou_allows_slight_overlap():
a = Box(0, 0.0, 0.0, 0.5, 0.5, 0.9)
b = Box(0, 0.4, 0.4, 0.9, 0.9, 0.8) # IoU 约 0.02
assert suppress_overlaps([a, b]) == [0]
assert suppress_overlaps([a, b], max_iou=0.1) == [0, 1]
def test_suppress_handles_empty_and_single():
assert suppress_overlaps([]) == []
assert suppress_overlaps([Box(0, 0.1, 0.1, 0.2, 0.2, 0.5)]) == [0]