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同样移动一个单位，小框为什么更吃亏","sha256":"91ec114e8c9402a4b3d228194d0893e24bfd0dbb2764f22b6a70874519c658e3","chapter":{"id":"II","title":"区域、像素与实例"},"unit":{"id":"detection-errors-and-evidence","title":"检测分数很高，错误究竟在哪里？"},"page":{"id":"reading-opening","title":"同样移动一个单位，小框为什么更吃亏","number":1},"sectionTitle":"同样移动一个单位，小框为什么更吃亏","currentQuestion":"同样移动一个单位，小框为什么更吃亏","sourceSlides":[],"knowledgeBlock":null,"formulas":[],"previousBlock":null,"nextBlock":"b-73d2666eb8b5408ef97afbb5","prerequisites":[{"id":"b-73d2666eb8b5408ef97afbb5","url":"#b-73d2666eb8b5408ef97afbb5","role":"problem-context"}],"relatedBlocks":[{"id":"b-be0b8e021e6217bb7031a5da","url":"#b-be0b8e021e6217bb7031a5da","relation":"figure-and-explanation"}]},{"id":"b-73d2666eb8b5408ef97afbb5","type":"p","scope":"iou-and-small-boxes","url":"https://codingai-lec03.pages.dev/course/blocks/iou-and-small-boxes.html#b-73d2666eb8b5408ef97afbb5","content":"从错类、漏检、框偏和重复四项错误读结果。IoU 把位置偏差变成可比较几何量，AP 再加入分数排序与对象唯一匹配。沿下方积分例走完分数排序、精确率与召回率计算，再用 LAB10 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d，边长为 w 且 $0\\le d<w$。交集面积 $(w-d)w$，并集 $(w+d)w$，于是 IoU=$(w-d)/(w+d)$。错开一个单位时，边长 10 的框 IoU=9/11，边长 2 的框却只有 1/3。绝对坐标误差相同，几何质量不同。","sha256":"a4e5d6aa0c8f013ed1b565b3ac5097f4deb419989596d8302954e25684358f1e","chapter":{"id":"II","title":"区域、像素与实例"},"unit":{"id":"detection-errors-and-evidence","title":"检测分数很高，错误究竟在哪里？"},"page":{"id":"reading-opening","title":"同样移动一个单位，小框为什么更吃亏","number":1},"sectionTitle":"同样移动一个单位，小框为什么更吃亏","currentQuestion":"同样移动一个单位，小框为什么更吃亏","sourceSlides":[],"knowledgeBlock":null,"formulas":[{"latex":"0\\le 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03 课堂图解 P35；漏检；没有报告蓝杯；错类别；红杯 → “花瓶”；偏位；重复；面积各 4 · 交集 2；IoU = 2 / (4 + 4 − 2) = 1/3；类别分数高，不会自动修正位置；检测错误要分开检查；完整匹配、阈值和 AP 协议在补充阅读。\n\n分类、位置、重复和遗漏是可分开的错误。 查看对应图解状态\n\n- 漏检\n- 没有报告蓝杯\n- 错类别\n- 红杯 → “花瓶”\n- 偏位\n- 重复\n- 面积各 4 · 交集 2\n- IoU = 2 / (4 + 4 − 2) = 1/3\n- 类别分数高，不会自动修正位置\n- 检测错误要分开检查；完整匹配、阈值和 AP 协议在补充阅读。分类、位置、重复和遗漏是可分开的错误。 [查看对应图解状态](/#/l3-r2-p35/0)[查看完整图解](/#/l3-r2-p35/0)","sha256":"470c11b12022a49d653607b198bfedd4e52c4f337aa398ef33d583ce54010b62","chapter":{"id":"II","title":"区域、像素与实例"},"unit":{"id":"detection-errors-and-evidence","title":"检测分数很高，错误究竟在哪里？"},"page":{"id":"reading-opening","title":"同样移动一个单位，小框为什么更吃亏","number":1},"sectionTitle":"同样移动一个单位，小框为什么更吃亏","currentQuestion":"同样移动一个单位，小框为什么更吃亏","sourceSlides":[],"knowledgeBlock":null,"formulas":[],"figure":{"caption":"分类、位置、重复和遗漏是可分开的错误。 查看对应图解状态","labels":["漏检","没有报告蓝杯","错类别","红杯 → “花瓶”","偏位","重复","面积各 4 · 交集 2","IoU = 2 / (4 + 4 − 2) = 1/3","类别分数高，不会自动修正位置","检测错误要分开检查；完整匹配、阈值和 AP 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