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Paper-Survey: Objects as Points

fam_taro
April 19, 2019

Paper-Survey: Objects as Points

fam_taro

April 19, 2019
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  1. ࿦จLT: Objects as Points
    h"ps:/
    /arxiv.org/abs/1904.07850
    2019/04/19 ౻ຊ༟հ
    1

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  2. ໨࣍
    • ஶऀ৘ใ
    • ֓ཁ
    • ͜Ε·ͰͷϞσϧͱͷҧ͍
    • ਫ਼౓
    • ͦͷଞײ૝
    2

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  3. ஶऀ৘ใ
    • Xingyi Zhou(UT Aus1n)
    • Dequan Wang(UC Berkeley)
    • Philipp Krähenbühl(UT Aus1n)
    3

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  4. ಛ௃
    • ෺ମݕग़Ϟσϧ
    • ༗໊ͳྫ: SSD, YOLOv3, Re.naNet, M2Det...
    • ݕग़ͷΈͳΒͣ࢟੎ɾdepthɾ޲͖ɾ3d size ౳ʹ΋ద༻͍ͯ͠Δ
    • backbone ͱͯ͠ DLA(deep layers aggrega.on) ΍ Hourglass(CornerNet ౳Ͱ࢖
    ༻) Λ࢖༻
    4

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  5. ಛ௃
    • bounding box Λ࢖Θͣʹݕग़Λߦ͏Ϟσϧ(keypointਪఆ)
    • bounding box ༻ͷ grid ͷ୅ΘΓʹ໨͕ࡉ͔͍ heatmap(H, W Λ4Ͱׂͬͨఔ
    ౓ͷ΋ͷ) Λग़ྗ
    • heatmap ͕ߴ͍৔ॴ(௖఺) Λ෺ମͷத৺ͱਪఆ
    • த৺ͱͳΔ৔ॴͷ feature ͔Β෺ମͷେ͖͞ɾ཭ࢄԽޡࠩΛਪఆ
    • ཭ࢄԽޡࠩ = heatmap ʹͨ͠ࡍͷޡࠩ
    • େ͖͞ʹ͍ͭͯ͸ scale ͍ͯ͠ͳ͍(ͦͷ··ͷ஋)
    5

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  6. ಛ௃
    • ༧ଌϘοΫε = heatmap ͷ࠲ඪ + ༧ଌϘοΫεαΠζ + ༧ଌ཭ࢄԽޡࠩ
    • ֶशʹ࢖͏ heatmap ͷ఺͸ 1෺ମʹ͖ͭ 1ͭͷΈ
    • SSD ౳ͷΑ͏ʹ IoU ͷॏͳΓ۩߹Ͱ background ͔൱͔Λ෼͚ͳ͍
    • ෳ਺ box ग़͞ͳ͍͜ͱΛલఏͱ͍ͯ͠Δ
    • ಉ͡ΫϥεͰॏͳͬͯ͠·͏৔߹͕͋Δ͕શମͷ 0.1 % ະຬͰ RCNN(2% ະ
    ຬ) ΑΓখ͍͞
    6

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  7. Πϝʔδਤ
    7

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  8. ͜Ε·ͰͷϞσϧͱͷҧ͍
    • Object detec*on with implicit anchors(SSD, YOLO, Re*naNet ౳)ͱͷҧ͍
    • CenterNet͸ശͷॏͳΓͰ͸ͳ͘ҐஔͷΈʹج͍ͮͯʮΞϯΧʔʯΛׂ౰
    • લܠͱഎܠͷ෼ྨʹؔ͢Δखಈͷ͖͍͠஋͸ͳ͍(IoU 0.5 > ͱ͔)
    • ෺ମຖʹϙδςΟϒͳΞϯΧʔ͸1͚ͭͩͳͷͰ NMS Λඞཁͱ͠ͳ͍
    • We simply extract local peaks in the keypoint heatmap
    • keypoint heatmap ͔ΒϩʔΧϧϐʔΫΛநग़͢Δ͚ͩͰྑ͍
    8

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  9. ͜Ε·ͰͷϞσϧͱͷҧ͍
    • Object detec*on with implicit anchors(SSD, YOLO, Re*naNet ౳)ͱͷҧ͍
    • CenterNet͸ΑΓେ͖ͳग़ྗղ૾౓Λ࢖͏
    • mask r-cnn ͱ͔ͱൺֱͯ͠
    • output stride of 16
    • ͜ΕʹΑΓෳ਺ͷΞϯΧʔ͕ෆཁͱͳΔʁʁʁʁ
    • [1711.08189] An Analysis of Scale Invariance in Object Detec*on - SNIP
    9

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  10. ͜Ε·ͰͷϞσϧͱͷҧ͍
    • Object detec*on by keypoint es*ma*on(CornerNet, ExtremeNet ౳)ͱͷҧ͍
    • ্ه 2ͭ͸ keypoint ݕग़ޙʹ ૊Έ߹ΘͤΛ grouping ͢Δඞཁ͕͋Δ
    • ஗͘ͳͬͯ͠·͏
    • CenterNet ͸ඞཁͱ͠ͳ͍
    • ଎͍ʂ
    10

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  11. ਫ਼౓
    11

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  12. ਫ਼౓(M2Det ͷ݁ՌΛ໨ࢹͰ௥Ճͯ͠Έͨ)
    12

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  13. ͦͷଞײ૝
    • Backbone ͱͯ͠ DLA Λ࢖͑ΔͷΛॳΊͯ஌ͬͨ
    • Ή͠Ζ DLA ॳΊͯ஌Γ·ͨ͠
    !
    • NMS ͕ෆཁʹͳΔͷ͸஍ຯʹخ͍͠
    • anchor ͕ফ͑Δͷ΋خ͍͠
    • খ͍͞෺ମʹରͯ͠ͲΕ͚ͩରԠͰ͖Δ͔֬ೝ͠ͳ͍ͱ
    13

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