TRUY XUT THNG TIN

MY HC V NG DNGHng dn khoa hc: GS.TSKH. HONG VN KIMNCS: Mai Tin DngBo co chuyn NCS1Ni dungGii thiuNi dung chuyn Xc nh cc im c trng cc bM t c trng nhCc phng php my hc v ng dngKt qu thc nghimKt lun v hng pht trin tip theo221. Gii thiuNhu cu tm kim v truy xut da trn cc khi nim ng ngha trong nh. Cn phi c nhng m hnh v cch m t nh sao cho c th xc nh cc khi nim c trong nh/video.

3Bi ton xc nh khi nimCho trc tp d liu hun luyn gm:Danh sch cc khi nimTp nh lin quan n khi nim: cho bit mt nh c cha nhng khi nim no v cc nh thuc cng mt khi nimYu cu: cn xc nh xem nh mi c cha nhng khi nim no ? y l bi ton phn lp nh trong trng hp mt nh c th thuc nhiu lp 4Nhng thch thcTp d liu l cc nh chia s t internet, hnh nh trong thc t,

5Nhng thch thcMt khi nim c nhiu nh khc nhau

timeofday_dayChair6Nhng thch thcMt nh c cha nhiu khi nim khc nhau

nh c cha 9 khi nim7Nhng thch thcD liu hun luyn b nhiu.( nh cha mt trng nh thuc khi nim timeofday_day hoc nh cha mt tri nhng c gn l timeofday_night )

8Nhng kt qu lin quanKt qu cao nht trong nm 2012 trn tp d liu ny c MiAP l 0.4367

9Nhng kt qu lin quanBng so snh kt qu gia cc khi nim

10M hnh chung xc nh khi nim

Cc khi nim11Rt trch c trng nhMi nh s c m t bng mt vector c trng sao cho c th thc hin cc tnh ton v so snh da trn vector c trng.Trong chuyn ny, chng ti xt cc c trng cc b da trn hnh nh (visual): SIFT, SURF,12c trng cc bCc bc xc nh c trng cc b:Xc nh cc im quan tm (keypoint, interest point) trong nh.M t cc im quan tm ( descriptors) bng vector nhiu chiu c dng s.

13c trng cc bGi l c trng cc b v kt qu so snh da trn nhng im cc b ging nhau gia hai nh

14Xc nh cc im keypointYu cu: xc nh cc im bt bin (hoc bin i nh) vi cc php bin i nh tnh tin, xoay, t l khc nhau, thay i sng, gc nhn khc nhau

15Xc nh cc im keypointC nhiu phng php: Hessain, Harris, SIFT, SURF,

16Cc phng php m t keypointC nhiu phng php m t:SIFT, SURF, ORB, BRIEF, FREAKColorDescriptorVD: ; 1 0 0 0 0 0 1 10 2 1 7 1 0 0 1 8 0 3 6 0 0 0 4 3 0 0 0 0 0 0 4 5 6 1 0 ....

17Biu din vector c trngV s lng descriptor trong nh thng rt ln v khc nhau ( t vi trm n vi chc nghn). Chi ph thc hin so snh tm im ging nhau gia cc nh l rt ln.

Cn phi biu din nh trong mt khng gian c s chiu ging nhau.18M hnh bag of wordXy dng t in cc t (visual word)

19M hnh bag of wordThng k tn sut cc t c trong nh vector c trng cho nh

20M hnh bag of wordV d: biu din vector c trng cho nh

21Cc thut ton my hcp dng phng php hc c gim st tin hnh xc nh cc khi nim: thut ton SVM,p dng phng php hc khng gim st xy dng cc visual word: thut ton K-Means, GMM,..22Qu trnh phn lp ( xc nh khi nim)Giai on hun luyn: da trn tp muXc nh cc nh thuc mu dng v

Cc nh thuc mu m

Dng phng php SVM hcGiai on kim tra: xc nh xem nh kim tra c cha khi nim khng ?

23Kt qu thc nghimTp d liu chun ca ImageClef 2012:Train: 15.000 nh (kch thc 500x, x500)Test: 10.000 nhS khi nim s dng 20/94c trng:S dng 3 phng php rt trch keypoint: SIFT, SURF v HARRISS dng 3 phng php m t tng ng: SIFT, SURF v ColorDescriptor (OpponentSIFT)

24Kt qu thc nghimPhng php my hc:Xc nh khi nim:SVM ( one versus all)Mu dng: da trn tp hun luynMu m: chn ngu nhinXc nh t trong t in: dng k-means++T inS dng 3 kch thc: 1.000, 1.500 v 2.000 t o: MAP v GMAP

25Kt qu thc nghim

26Kt qu thc nghimKt qu theo o MAP cho 20 khi nim

27Kt qu thc nghimKt qu theo o GMAP cho 20 khi nim

28Kt qu thc nghimKt qu theo o GMAP cho 20 khi nim

29Kt qu thc nghimSo snh kt qu thc nghim trong chuyn so vi kt qu cao nht trong ImageClef 2012

30Kt lun v hng pht trinKt lun:Nghin cu v tm hiu v cc phng php m t nh da trn cc c trng cc b.S dng m hnh bag of word m t nh. Cc phng php my hc ng dng trong bi ton xc nh khi nim.Tin hnh thc nghim trn tp d liu chun lin quan31Kt lun v hng pht trinHng pht trin: Tin hnh thm thc nghim trn cc b m t khc nhau, kt hp vi cc phng php xc nh im quan tm. Tng kch thc t in kim tra mi lin quan gia t in v chnh xc. Tng s lng khi nim thc nghim.Chn lc d liu hc v th nghim cc phng php phn lp khc ngoi phng php SVM.Vit bi bo da trn kt qu t c.32Gp ca hi ngThy Kim: tn chuyn nn i thnh xc nh khi nim trong nh da trn thut ton my hc ph hp hn.Thy Kh: Nn i theo kin Thy Kim v in li.Phn related work: nn b sung trong 6 cng trnh vit li khong 3 trang. V y l bi ton quan trng: bt buc hnh nh = ting ni.

33Gp ca hi ngThy Kh: Cch t vn bi ton: cn xc nh r, nn chn mt trong s tltk gn vi lun n nht tp trung chuyn su hn.Trong phn thc nghim: b st phn bnh v kt qu, cn cho bit kt qu , phng php , ngun ti liu so snh, nu tc dng ca n i vi pp ca mnh, trin vng trong pp ca mnh.Cu hi: da trn u xc nh c trng ? Ngoi k-means c s dng SNN ?34Gp ca hi ngThy Nhn: Bi ton m t cha r v khi nim, biu din n nh th no, cn c xc nh khi nim ( tp nh ), m t nh th no bit khi nim.

Tp.HCM, ngy 28/02/201335