Шупейко Н.П.

Òåçèñû êîíôåðåíöèè ¾Ëîìîíîñîâ 2015¿
Àâòîìàòèçàöèÿ àíàëèçà àýðîôîòîñíèìêîâ
äëÿ ó÷¼òà æèâîòíûõ
Øóïåéêî Íèêèòà Ïàâëîâè÷
Ñòóäåíò (áàêàëàâð)
Ôàêóëüòåò ÊèÁ, ÍÈßÓ ¾ÌÈÔÈ¿, Ìîñêâà, Ðîññèÿ
E-mail:
[email protected]
Ñåãîäíÿ âñ¼ áîëüøóþ àêòóàëüíîñòü ïðèîáðåòàåò ïðîáëåìà àâòîìàòèçàöèè àíàëèçà ôîòîñíèìêîâ, ïîëó÷àåìûõ ñ îðáèòû, áîðòîâ ïèëîòèðóåìûõ è áåñïèëîòíûõ ëåòàòåëüíûõ àïïàðàòîâ. Îäíèì èç àñïåêòîâ ïðàêòè÷åñêîãî ïðèìåíåíèÿ ïðîãðàììíûõ ðåøåíèé ïîñòàâëåííîé çàäà÷è ÿâëÿåòñÿ ìîíèòîðèíã ÷èñëåííîñòè îñîáåé íà òåððèòîðèÿõ
ïðèðîäíûõ çàïîâåäíèêîâ è åñòåñòâåííûõ àðåàëîâ îáèòàíèÿ ñ öåëüþ
ñîõðàíåíèÿ è ïðèóìíîæåíèÿ áèîðàçíîîáðàçèÿ.
 ðàáîòå ïðåäëàãàåòñÿ àëãîðèòì îáíàðóæåíèÿ è ïîäñ÷¼òà ñàéãàêîâ íà ñåðèè àýðîôîòîñíèìêîâ. Åãî ïîâåäåíèå çàâèñèò îò çíà÷åíèé
óïðàâëÿþùèõ ïàðàìåòðîâ (äàëåå ÓÏ):
1.
SpeciesBodyLength (SBL) íàèáîëüøèé õàðàêòåðèñòè÷åñêèé
2.
TopIntensitySampleLength (TISL) äëèíà âûáîðêè ¾òîïîâûõ¿
ÿðêîñòåé òî÷åê èçîáðàæåíèÿ;
3.
ContourVerticesAngle (CVA) óãëîâîé øàã ïîâîðîòà ïðÿìîé,
âäîëü êîòîðîé èùóòñÿ ãðàíè÷íûå òî÷êè;
4.
MaxColorDierence (MCD ) ìàêñèìàëüíî äîïóñòèìîå öâåòî-
5.
MinSpeciesBodyArea (MinSBA) ìèíèìàëüíî äîïóñòèìàÿ
6.
MaxSpeciesBodyArea (MaxSBA) ìàêñèìàëüíî äîïóñòèìàÿ
ïëîùàäü îáëàñòè ïðåäïîëàãàåìîãî íàõîæäåíèÿ îñîáè.
ðàçìåð òåëà îñîáè;
âîå ðàçëè÷èå ìåæäó îïîðíîé òî÷êîé è òî÷êîé, íå ÿâëÿþùåéñÿ
ãðàíè÷íîé, â öâåòîâîì ïðîñòðàíñòâå CIE Lab;
ïëîùàäü îáëàñòè ïðåäïîëàãàåìîãî íàõîæäåíèÿ îñîáè;
Òðåáîâàíèÿ ê ýôôåêòèâíîñòè àëãîðèòìà: íå ìåíåå 85% îáíàðóæåííûõ îñîáåé è íå áîëåå 8% ëîæíîïîëîæèòåëüíûõ ñðàáàòûâàíèé.
Íà ïåðâîì ýòàïå âõîäíîå èçîáðàæåíèå ïðåîáðàçóåòñÿ â èçîáðàæåíèå â îòòåíêàõ ñåðîãî, â ðåçóëüòàòå ïîïèêñåëüíîãî îáõîäà êîòîðîãî ôîðìèðóåòñÿ âûáîðêà äëèíû TISL èç íàèáîëüøèõ (¾òîïîâûõ¿)
1
Òåêóùàÿ ñåêöèÿ
çíà÷åíèé ÿðêîñòè òî÷åê èñõîäíîãî èçîáðàæåíèÿ. Êàæäîìó ýëåìåíòó
ýòîé âûáîðêè ñîïîñòàâëåí íàáîð òî÷åê, îáëàäàþùèõ äàííîé ÿðêîñòüþ áóäåì íàçûâàòü èõ îïîðíûìè (äàëåå ÎÒ).
Íà âòîðîì ýòàïå îêðåñòíîñòü êàæäîé ÎÒ àíàëèçèðóåòñÿ â ðàäèàëüíîì íàïðàâëåíèè (ðàññìàòðèâàþòñÿ âñå òî÷êè, ëåæàùèå íà ëó÷å
ñ íà÷àëîì â ÎÒ): ïîñëåäîâàòåëüíî âû÷èñëÿåòñÿ öâåòîâîå ðàçëè÷èå
(åâêëèäîâî ðàññòîÿíèå â ïðîñòðàíñòâå CIE Lab [3]) ìåæäó òåêóùåé
òî÷êîé è ÎÒ åñëè îíî ïðåâûøàåò MCD, ðàññìàòðèâàåìàÿ òî÷êà
ïðèçíà¼òñÿ ãðàíè÷íîé. Çàòåì ëó÷ ïîâîðà÷èâàåòñÿ íà óãîë CVA è ïðîöåäóðà ïîâòîðÿåòñÿ. Ïîñëå ïîëíîãî ïîâîðîòà ïîëó÷åííûå ãðàíè÷íûå
òî÷êè ñîåäèíÿþòñÿ ëîìàíûìè è ýòàï ïîâòîðÿåòñÿ äëÿ ñëåäóþùåé
ÎÒ.
Ê íà÷àëó òðåòüåãî ýòàïà ÎÒ çàêëþ÷åíû âíóòðè çàìêíóòûõ êîíòóðîâ, îãðàíè÷èâàþùèõ îáëàñòè ïðåäïîëàãàåìîãî íàõîæäåíèÿ îñîáåé. Çàìåòèì, ÷òî åñëè íà òåëå îñîáè èçíà÷àëüíî áûëî îáíàðóæåíî
íåñêîëüêî ÎÒ, ïîñòðîåííûå íà íèõ îáëàñòè ñëåäóåò îáúåäèíèòü ïðèìåíÿåòñÿ àëãîðèòì Âàòòè îòñå÷åíèÿ ìíîãîóãîëüíèêîâ [5].
Íà çàêëþ÷èòåëüíîì ýòàïå äëÿ ïðîèçâîëüíîé îáëàñòè ââîäèòñÿ
ïîíÿòèå ¾îêðóãëîñòè¿
p2
(1)
R(p, S) = ,
S
ãäå p è S ïðèáëèçèòåëüíûå çíà÷åíèÿ ïåðèìåòðà è ïëîùàäè îáëàñòè. Ââèäó áëèçîñòè ôîðìû îáëàñòè ê ýëëèïòè÷åñêîé
R(SBL, S) = 16
2S
2 2
[S + ( SBL
2 − πSBL ) ]
.
2S
2
( SBL
2 + πSBL ) S
(2)
Òå îáëàñòè, ó êîòîðûõ
S∈
/ [M inSBA, M axSBA], or
(3)
R∈
/ [R(SBL, M axSBA), R(SBL, M inSBA)],
(4)
èñêëþ÷àþòñÿ èç ðàññìîòðåíèÿ.
Îòûñêàíèå îïòèìàëüíûõ çíà÷åíèé ÓÏ ïðîâîäèëîñü íà ¾îáó÷àþùåé¿ âûáîðêå, ïîëîâèíà ñíèìêîâ â êîòîðîé çàïå÷àòëåëè õîòÿ áû
îäíó îñîáü. Ýêñïåðèìåíòàëüíî ïîëó÷åíû çíà÷åíèÿ (ïî íîìåðàì ÓÏ):
1
2
3
4
5
6
R(61, 1573)
R(61, 419)
61
6
0,06
0,42
419
1573
14,50
38,11
2
Òåçèñû êîíôåðåíöèè ¾Ëîìîíîñîâ 2015¿
 ñðàâíåíèè ñ [1], [2], [4] ðàçðàáîòàííûé àëãîðèòì áîëåå ñïåöèàëèçèðîâàííûé: ïðè óñëîâèè âûáîðà îïòèìàëüíûõ çíà÷åíèé ÓÏ íà
âõîäíûõ èçîáðàæåíèÿõ óäà¼òñÿ âåðíî îïðåäåëèòü ìåñòîïîëîæåíèå
92% îñîáåé ïðè ÷àñòîòå ëîæíîïîëîæèòåëüíûõ ñðàáàòûâàíèé â 6%,
÷òî óäîâëåòâîðÿåò ïðåäúÿâëåííûì òðåáîâàíèÿì.
Èëëþñòðàöèè
Ñëåâà: ôðàãìåíò âõîäíîãî èçîáðàæåíèÿ, èìåþùåãî ðàçìåð 5184x3456;
ñïðàâà: îí æå, çàòåí¼ííûé äëÿ ðàçëè÷èìîñòè êîíòóðîâ
Ëèòåðàòóðà
1. Yang Z., Wang T., Skidmore A. K., de Leeuw J., Said M. Y., and et
al. Spotting East African Mammals in Open Savannah from Space
// PLoS ONE. 2014. V. 9,  12.
2. Terletzky P., Ramsey R. D. A Semi-Automated Single Day Image
Dierencing Technique to Identify Animals in Aerial Imagery //
PLoS ONE. 2014. V. 9,  1. 17.
3. Bildstein J. Colors. Color models, Conversions and Color Dierence
in Formulas and Code // 2013.
4. Sirmacek B., Wegmann M., Cross J., Hopcraftd P. R., Dech S.
Automatic population counts for improved wildlife management
using aerial photography // In Managing Resources of a Limited
Planet, Sixth Biennial Meeting, Leipzig, Germany, 2012.
5. Vatti B. R. A generic solution to polygon clipping //
Communications of the ACM. 1992. V. 35,  7, 5663.
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