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7/30/2019 Nhan dien bien so xe dung Neural
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B GIO DC V O TOTRNG I HC DN LP HI PHNG
-------o0o-------
N TT NGHIPNGNH CNG NGH THNG TIN
HI PHNG 2009
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B GIO DC V O TO
TRNG I HC DN LP HI PHNG
-------o0o-------
TM HIU BI TON NHN DNG BIN S XE
N TT NGHIP I HC H CHNH QUY
Ngnh: Cng ngh thng tin
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MC LC
B GIO DC V O TO .................................................................................9B GIO DC V O TO ...............................................................................10
TM HIU BI TON NHN DNG BIN S XE ................................ 10
N TT NGHIP I HC H CHNH QUY .............................................10Ngnh: Cng ngh thng tin ....................................................................................10
11
B GIO DC V O TOTRNG I HC DN LP HI PHNG
-------o0o-------
TM HIU BI TON NHN DNG BIN S XE
N TT NGHIP H CHNH QUYNgnh: Cng ngh thng tin
Sinh vin thc hin: Phm Th Thanh ThuGio vin hng dn: PGS.TS. NNG TONM s sinh vin: 090125
Hi Phng - 2009
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B GIO DC V O TO ...............................................................................11TM HIU BI TON NHN DNG BIN S XE ................................ 11
PHN GII THIU .................................................................................................14Chng 1: ....................................................................................................... 15
TNG QUAN V BI TON NHN DNG BIN S XE .....................151.1. Khi qut v x l nh: ..............................................................................................151.2. Khi nim v nhn dng bin s xe: ..........................................................................15
1.2.1 Khi nim & ng dng: ....................................................................................... 151.2.2 Phn loi bin s xe: ...........................................................................................18
1.3. Mt s hng gii quyt bi ton nhn dng bin s xe: ...........................................211.3.1. Hng tip cn pht trin vng: ......................................................................... 211.3.2. Hng tip cn d bin v bin i Hough: .......................................................21
1.4 Hng gii quyt: ........................................................................................................22Chng 2: ....................................................................................................... 25
PHT HIN VNG CHA BIN S XE ..................................................252.1 Mt s khi nim c bn: ............................................................................................25
2.1.1 Tng quan v nh .................................................................................................252.1.2 Phng php tch d ngng t ng ...............................................................26
2.2 Bin v cc phng php pht hin bin...................................................................272.2.1 Phng php gradient ..........................................................................................272.2.2. K thut Laplace: ................................................................................................30
2.3 Pht hin vng cha bin s xe ...................................................................................322.3.1. Nh phn ha nh ................................................................................................322.3.2 Tch bin: .............................................................................................................33
2.3.3 Bin i HOUGH ................................................................................................ 352.3.4 Trch chn on thng v tnh giao im .............................................................38
2.3. Xc nh chnh xc vng cha bin s xe ..................................................................392.3.1. Bc ban u: .....................................................................................................402.4.2 Tiu ch t l chiu di/rng................................................................................412.4.3 Tiu ch s k t trong vng bin s xe ...............................................................42
Chng 3: ....................................................................................................... 43
BI TON NHN DNG K T .............................................................. 43
3.1 Tng quan v nhn dng .............................................................................................43
3.1.1 Khng gian biu din i tng, khng gian din dch .......................................433.1.2 M hnh v bn cht ca qu trnh nhn dng ....................................................44
3.1.2.1 M hnh .........................................................................................................443.1.2.2 Bn cht ca qu trnh nhn dng ................................................................46
3.2 M hnh mng nron nhn to ....................................................................................473.2.1 M hnh nron nhn to .......................................................................................473.2.2 Mng Nron .........................................................................................................48
3.2.2.1 Phn loi cc mng noron .............................................................................493.2.2.2 Hai chc nng ca mng noron .....................................................................50
3.2.3 Mng Kohonen ....................................................................................................523.2.3.1 Cu trc mng ...............................................................................................52
3.2.3.3 S dng mng ............................................................................................... 553.2.4 Mng nron nhiu lp lan truyn ngc sai s ................................................... 57
3.2.4.1 Kin trc mng ..............................................................................................57
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3.2.4.2 Hun luyn mng ..........................................................................................573.2.4.3 S dng mng ............................................................................................... 59
3.3 S dng mng nron lan truyn ngc hng cho nhn dng k t ..........................593.3.1 Nhn dng bng mng nron lan truyn ngc hng (kn chung) .....................593.3.2 Ci t mng lan truyn ngc hng cho nhn dng k t ...............................603.3.3 Nhn dng cc k t s dng mng lan truyn ngc hng ............................62
PHN KT LUN ...................................................................................................63TI LIU THAM KHO ........................................................................................65
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PHN GII THIU
Ngy nay trn th gii bn cnh vic tng trng kinh t l s pht trin
ca cc ngnh khoa hc k thut ni chung, m trong ngnh cng nghip sn
xut cc phng tin giao thng li l mt trong nhng ngnh c tc phttrin cc nhanh. S pht trin y, c th hin r rng nht thng qua hnh nh
cc phng tin giao thng trn th gii ngy mt tng cao v a dng. Tuy
nhin,iu li gy ra mt p lc i vi nhng ngi v c quan cc cp
qun l,lm cho cng tc qun l v gim st s kh khn hn,
V y cng l mt trong nhng vn nn Vit Nam. Cng tc qun l
phng tin giao thng ni chung v qun l t, xe my l v cng phc tp
cng nh cng tc pht hin, x pht cc hnh vi vi phm giao thng, chng
trm,s tn nhiu thi gian v cng sc hn
lm gim lng nhn lc trong vic cng tc qun l, kim sot
phng tin giao thng, trn th gii nhanh chng xy dng h thng gim
st t ng i vi cc phng tin giao thng. V cc h thng gim st u
ly bin s xe l mc tiu gim st. H thng ny c s dng rng ri tuy
nhin Vit Nam y vn l mt lnh vc mi m.
Do em chn lm ti Tm hiu h thng nhn dng bin s xe vi
mc ch tm hiu nhm tr gip cho cng tc gim st, qun l cc phng
tin giao thng mt cch hiu qu, d dng v nhanh chng hn
Em tin Vit Nam mnh trong tng lai gn h thng ny s c s
dng rng ri.
B cc trnh by trong bo co ca em gm 3 phn:
Chng 1: Tng quan v bi ton nhn dng bin s xe
Chng 2: Pht hin vng cha bin s xe
Chng 3: Nhn dng k t
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Chng 1:
TNG QUAN V BI TON NHN DNG BIN S XE
1.1. Khi qut v x l nh:X l nh l mt trong nhng mng quan trng nht trong k thut th
gic my tnh, l tin cho nhiu nghin cu thuc lnh vc ny. Hai nhim v
c bn ca qu trnh x l nh l nng cao cht lng thng tin hnh nh v x
l s liu cung cp cho cc qu trnh khc trong c vic ng dng th gic
vo iu khin.
Qu trnh bt u t vic thu nhn nh ngun (t cc thit b thu nhn nh
dng s hoc tng t) gi n my tnh. D liu nh c lu tr nh dng
ph hp vi qu trnh x l. Ngi lp trnh s tc ng cc thut ton tng
ng ln d liu nh nhm thay i cu trc nh ph hp vi cc ng dng khc
nhau.
- Chuyn nh mu thnh nh xm
- Lc xm ca nh (Histogram)
- Cc b lc khng gian
+ Lc tuyn tnh
+ Lc phi tuyn
- Tch bin i tng
1.2. Khi nim v nhn dng bin s xe:
1.2.1 Khi nim & ng dng:
a) Khi nim:
H thng nhn dng bin s xe l h thng c kh nng phn tch hnh
nh v xc nh bin s trn xe, thng qua video, thit b ghi hnh v hnh nh.
Sau cng l xc nh cc thng tin nh: ch s hu xe, theo di xe vi tc
chm, ....
*) Phn loi ng dng nhn dng bin s xe:
ng dng nhn dng bin s xe l ng dng c kh nng phn tch hnh
nh v xc nh bin s xe t cc hnh nh chp c t cc thit b thu hnh.
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Ngun hnh nh cho ng dng c rt nhiu. V pht trin, hnh nh c trc
tip thu nhn t camera. Trong bo co tt nghip ca em ch dng li mc
xc nh c bin s xe (xc nh cc ch) t cc bc nh.
C nhiu cch thc khc nhau phn loi cc ng dng nhn dng bin
s xe. Mt trong nhng cch n gin l phn loi ng dng nhn dng bin s
xe thng qua mc ch s dng. C th chia ng dng nhn dng bin s xe
thnh hai loi sau:
Loi 1: Gii hn vng nhn
u vo: nh thu trc tip t cc thit b ghi nhn nh k thut s. nh
c ghi nhn thng ch gii hn trong vng c bin s xe.
Nguyn l hot ng: Cc phng tin giao thng phi chy vi mt tc
chm my ghi nhn hnh nh co th thu c nh vng bin s xe.
ng dng: Nhng ng dng nhn dng bin s xe loi ny thng c
dung ti cac trm kim sot, cc trm thu ph, cc bi gi xe t ng, cc trm
gc cng.
Loi 2: Khng gii hn vng nhn
u vo: nh u vo thu c t cc thit b ghi hnh t ng, khng
ph thuc vo gc , cc i tng xung quanh, nh khng cn bt buc ch
chp vng cha bin s xe, m c th nh tng hp nh cha them cc i
tng nh ngi, cy, ng ph.., min l vng bin s xe phi r c th
thc hin nhn dng c cc k t trong vng .
Nguyn l hot ng: Do c tnh khng gii hn vng nhn m nh u
vo c th thu c t mt thit b ghi hnh (camara, my nh). V do ,
cng vic u tin l d tm trong nh, xc nh ng vng no l bin s xe.
Sau , thc hin tch vng v nhn dng. Cui cng ty thuc vo mc ch s
dng m kt qu nhn dng c truyn i hay lu tr phc v nhu cu ca
ngi dng cui.
ng dng: V khng ph thuc vo hnh nh thu c nn c th dng
ng dng ti nhiu ni nh ti nhng ni iu tit giao thng, ti cc v tr nhy
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cm ca giao thng nh ng ba, ng t ng giao nhau. Kim sot, pht hin
nhng hnh vi vi phm an ton giao thng.
Yu cu v thit b:
- My qut
- en chiu
- B phn thu tch hnh nh
- My tnh
- Cc thit b khc ty mc ch s dng
Trong qu trnh tm hiu, xy dng ng dng ca mnh. ng dng m em
hng ti trong qu trnh xy dng l ng dng loi 2. V vy, trong ton b bo
co ny, ch nu cch thc gii quyt l lm sao nhn dng (lc ra) c cc k
t s v ch.
b)ng dng ca h thng nhn dng bin s xe:
H thng nhn dng bin s xe c xy dng nhm mc ch gim st,
kim sot cc phng tin. Di y chng ta cp n mt s ng dng ph
bin i vi h thng nhn dng bin s xe:
+) Thu ph giao thng: Lp t h thng Nhn dng bin s xe ti cc
trm thu ph nhm h tr hoc t ng ha cng tc thu ph.
+) Kim sot xe ti cc ng bin gii: Mi quc gia u c nhng quy
nh ring v bin s xe, phc v cho cng tc qun l v pht hin nhng
phng tin giao thng (xe) vt bin gii bt hp php. Vic lp h thng
Nhn dng bin s xe ti cc trm kim sot s gp phn h tr cng tc kim
tra v an ninh quc gia.
+) Cc trm gc cng: Vic lp t h thng Nhn dng bin s xe s
h tr hoc t ng ha cng tc m cng cho xe vo.
Ngoi ra, h thng cn c ng dng vo cng tc chng trm xe, cc
bi gi xe t ng, iu tit giao thng (chng hn nh Thnh ph Dublin
ng dng cng ngh Nhn dng bin s xe t ng trong vic iu tit giao
thng theo dng bin s chn/l)
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1.2.2 Phn loi bin s xe:
Trc tin l quy nh bin s ca 64 tnh thnh (Bin trng ch en):
11 - Cao Bng
12 - Lng Sn
14 - Qung Ninh
15,16 - Hi Phng
17 - Thi Bnh
18 - Nam nh
19 - Ph Th
20 - Thi Nguyn
21 - Yn Bi
22 - Tuyn Quang
23 - H Giang
24 - Lo Cai
25 - Lai Chu
26 - Sn La
27 - in Bin
28 - Ha Bnh
29,30,31,32 - H Ni
33 - H Ty
34 - Hi Dng
35 - Ninh Bnh
36 - Thanh Ha37 - Ngh An
38 - H Tnh
43 - Nng
47 - c Lc
48 - c Nng
49 - Lm ng
50 n 59 - TP. H Ch
Minh
60 - ng Nai
61 - Bnh Dng
62 - Long An
63 - Tin Giang
64 - Vnh Long
65 - Cn Th
66 - ng Thp
67 - An Giang
68 - Kin Giang
69 - C Mau
70 - Ty Ninh
71 - Bn Tre
72 - B Ra - Vng Tu
73 - Qung Bnh
74 - Qung Tr75 - Hu
76 - Qung Ngi
77 - Bnh nh
78 - Ph Yn
79 - Khnh Ha
80 - Cc n v kinh t
thuc TW (hng khng)
81 - Gia Lai
82 - KonTum
83 - Sc Trng
84 - Tr Vinh
85 - Ninh Thun
86 - Bnh Thun
88 - Vnh Phc
89 - Hng Yn
90 - H Nam
92 - Qung Nam
93 - Bnh Phc
94 - Bc Liu
95 - Hu Giang
97 - Bc Cn
98 - Bc Giang
99 - Bc Ninh
*)Nhng quy nh v mu sc v ch s c bit:
1. Mu xanh ch trng l bin xe ca cc c quan hnh chnh s nghip:
- Trc thuc chnh ph th l bin xanh 80
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- Cc tnh thnh th theo s tng ng
2. Mu ch trng l bin xe trong qun i:
AT: Binh on 12
AD: Qun on 4 , Binh on cu long
BB: b binh
BC: Binh chng Cng Binh
BH: Binh chng ho hc
BS: Binh on Trng Sn
BT: Binh chng thng tin lin lc
BP: B t lnh bin phng
HB: Hc vin lc qun
HH: Hc vin qun y
KA: Qun khu 1
KB: Qun khu 2
KC: Qun khu 3
KD: Qun khu 4
KV: Qun khu 5
KP: Qun khu 7
KK: Qun khu 9
PP: Cc qun y vin
QH: Qun chng hi qun
QK, QP: Qun chng phng khng khng qun
TC: Tng cc chnh trTH: Tng cc hu cn
TK: Tng cc cng nghip quc phng
TT:Tng cc k thut
TM: B tng tham mu
VT: Viettel
3. Mu trng 2 ch, 5 s l bin dnh cho ngi nc ngoi:- NG l xe ngoi giao
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- NN l xe ca cc t chc, c nhn nc ngoi: Trong 3 s gia l
m quc gia, 2 s tip theo l s th t.
* Xe s 80 NG xxx-yy l bin cp cho cc i s qun, thm gch
gia v 2 s cui l 01 l bin xe ca tng lnh s
4. Nhng xe mang bin 80 gm c :
- Cc Ban ca Trung ng ng
- Vn phng Ch tch nc
- Vn phng Quc hi
- Vn phng Chnh ph
- B Cng an
- Xe phc v cc ng ch u vin Trung ng ng cng tc ti H Ni
v cc thnh vin Chnh ph
- B ngoi giao
- Vin kim sot nhn dn ti cao
- To n nhn dn ti cao
- i truyn hnh Vit Nam
- i ting ni Vit Nam
- Thng tn x Vit Nam
- Bo nhn dn
- Thanh tra Nh nc
- Hc vin Chnh tr quc gia
- Ban qun l Lng, Bo tng, khu Di tch lch s H Ch Minh;
- Trung tm lu tr quc gia- U ban Dn s k hoch ho gia nh
- Tng cng ty Du kh Vit Nam
- Cc i s qun, t chc quc t v nhn vin ngi nc ngoi
- U ban Chng khon Nh nc
- Cc Hng khng dn dng Vit Nam
- Kim ton nh nc
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5. Cc bin A :
Xe ca Cng An - Cnh St tng ng vi cc tnh
v d: 31A = xe ca Cng An - Cnh St thnh ph H Ni
1.3. Mt s hng gii quyt bi ton nhn dng bin s xe:
C rt nhiu phng php tip cn. Trong c hai cch tip cn ph bin
di y:
1.3.1. Hng tip cn pht trin vng:
Nhm tc gi Nigel Whyte and Adrien Kiernan c i din cho cch
tip
cn ny
tng ca phng php ny: l bin s xe thng cha mt mu
ng nht, chng hn mu trng, v c din tch tng i nht nh. V vy c
th dng phng php pht trin vng, hoc s dng khung ch nht di chuyn
trong tm ra vng c tnh cht tha mn bin s xe v tin hnh nhn dng.
u im: rt n gin, v x l rt nhanh i vi nhng nh ch cha
vng bin s xe.
Nhc im: khi nh c thm nhiu i tng khng phi l vng bin
s xe, chng hn l nh chp tng qut gm c cnh vt bn ngoi th cch tip
cn ny tr nn khng hiu qu. V vy phng php ny rt hiu qu i vi h
thng trm thu ph, trm gc cng, gi xe t ng
1.3.2. Hng tip cn d bin v bin i Hough:
Nhm tc gi Michael Lidenbaum, Rosen Alexander, Vichik Sergey,
Sandler Roman c i din cho cch tip cn ny.
tng ca cch tip cn ny l: Bin s xe c bao boc bi ng
vin. Do , c th dng phng php pht hin bin, sau dng php bin i
Hough trch nhng on thng dc, ngang tn ti trong nh. Giao im ca
nhng on thng ny chnh l vng bao cha bin s xe. V cui cng l tin
hnh nhn dng cc k t trn mi vng con.
u im: chnh xc cao. V cc h thng nhn dng a phn u
pht trin theo hng tip cn ny.
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Nhc im: phc tp tnh ton kh cao. Khi nh c thm nhiu
i tng khc th khi lng tnh ton tng ln rt nhiu. Do mc ch l phi
xc nh c vng con no cha bin s xe.
Ngoi hai cch tip cn trn, cn c nhiu cch tip cn khc xc nh
chnh xc vng no cha bin s xe v bc cui cng l tin hnh nhn dng
k t. Mi cch tip cn c mt u v nhc im. a s cc ng dng u s
dng cch tip cn bin i Hough.Trong bo co ti ca em,em xin trnh by
cch tip cn Hough.
1.4 Hng gii quyt:
phn 1.3 chng ta tm hiu 2 hng gii quyt cho vic xc inh
vng cha bin s xe. Mi cch gii quyt c nhng u im v hn ch ring
ca n.
*) Mt s c im v bin s xe Vit Nam:
Tiu chun v kch thc: mi nc thng c tiu chun v kch
thc nht nh. i vi nc ta, bin s xe qui nh kh ng u cho mi loi
xe, t l chiu di, rng cho mi loi xe l nh nhau. i vi loi xe c mt
hng k t th t l di/ rng l: 5.4/5.3 HW . i vi loi xe c hai hng k
t th t l l: 4.1/8.0 HW . T cc c tnh ny, ta c th xc nh c
cc vng con tha mn cc tiu ch v ngng t l di/rng. V ch nhng vng
con tha mn th kh nng cha bin s xe l cao
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S lng k t trong bin s xe. Mi k t thng c t l kch thc
v chiu rng, chiu cao tng ng vi chiu di v rng ca bin s xe. V d,
chiu cao ca mi k t lun nh hn 85% chiu cao ca bin s xe v lun ln
hn 33% chiu cao ca bin xe. Cn chiu rng ca k t khng ln hn 20%
chiu di ca bin s xe. Mi k t ca bin s xe c xem nh l mt vng
lin thng con. Do , chng ta c th m vng lin thng con tha mn tnh
cht l k t. Ch s k t trn bin s xe l t 6 n 10 k t. nc ta
ch c s k t trn mi bin s xe nm trong khong 6 n 8 k t. Vy ta c
th dng ngng [6.8] nhn dng vng bin s xe.
T nhng nhn xt trn, chng ta c th a ra gii php cho bi ton
nhn dng: s dng phng php pht hin bin v bin i Hough. Sau , s
dng hai tnh cht trn bin s xe xc nh chnh xc vng con cha bin s
xe. Khi xc nh chnh xc vng con cha bin s xe th tin hnh nhn dng
cc k t.
gii quyt bi ton nhn dng bin s xe, trong bo co em xin trnh
by 3 bc nh sau:
Bc 1: nh vo nh mc xm I(x,y) thc hin theo phng php d
bin v bin i Hough tm ra cc vng con c kh nng cha bin s xe. Gi
tp con ny l Ic.
Bc 2: Xc nh chnh xc vng con no cha bin s xe bng hai
thao tc c miu t trn l tiu ch t l chiu di vi chiu rng v s k
t trong bin s xe. Kt qu ca bc 2 l cho ra mt tp nh con cha bin s
xe. Gi tp con ny l'cI .
Bc 3: Gii quyt bi ton nhn dng k t cho tp 'cI . Bng cch p
dng phng php v k thut nhn dng k t
Qua ba bc nh trn ta c th nhn dng c bin s xe 'cI . Trong
bc 3: nhn dng k t em s dng phng php mng noron truyn ngc
cho vic nhn dng k t.
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Trong phn tip theo l chi tit tng bc x l bi ton nhn dng
bin s xe, v mt s khi nim c bn quen thuc m c lin quan n nhn
dng bin s xe.
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Chng 2:
PHT HIN VNG CHA BIN S XE
2.1 Mt s khi nim c bn:
2.1.1 Tng quan v nha. nh v im nh:
nh l mng s thc hai chiu ( )nmI , , c kch thc (MxN), trong mi
gi tr ( )nmI , (ti mt im nh), biu th mc xm ca nh ti v tr ( )nm, tng
ng
Mt nh l nh nh phn nu gi tr ( )nmI , bng 0 hoc 1.
b. Mc xm:Mc xm l kt qu s m ha tng ng mt cng sang ca mi
im nh vi mt gi tr s- kt qu ca qu trnh lng ha. Cch m ha kinh
in thng dng 16, 32, 64. M ha 256 mc l ph dng nht do l do k
thut. V 28= 256, nn vi 256 mc, mi pixel c m ha 8bit.
c. i tng nh:
Trong phn ny ta ch xt vi nh nh phn, v mi nh nh phn u cth a v nh nh phn bng cc k thut phn ngng. Ta k hiu E l tp cc
im vng (im en) v E l tp cc im nn (im trng). Hai im Is v Ie
nmI , nm trong E (hoc E ) c gi l 4 lin thng (8 lin thng) nu tn
ti mt dy cc im gi l ng i:
( )00 , ji = Is v ( )nn ji , = Ie
( )
00, ji
( )11, ji
.( )
nn
ji ,
m( ) Eji
kk,
vi mi k= 0,1,n ( )kk ji , l 4 lng ging (8 lng ging) ca ( )11 , kk ji vi mi k= 1, 2,
,n
d. 4- Lng ging v 8- lng ging:
Nu ( )nm, l mt im nh, th 4 lng ging ca n l cc im ngay
bn trn, di, phi, v tri. Ta k hiu 4N l tp 4 lng ging ca im ( )nm, .
4N ( ) ( ) ( ) ( ){ }1,,1,,,1,,1 ++= nmnmnmnm
Tng t ta c tp 8- lng ging 8N
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8N ( ) ( ) ( ) ( ){ }1,1,1,1,1,1,1,14 ++++= nmnmnmnmN
e. Chu tuyn ca nh:
nh ngha chu tuyn:
Chu tuyn ca mt i tng nh ( )nmI , l dy cc im ca i tng:
nppp ....10 . Sao cho 1ip , 1+ip l 8 lng ging ca ip , Ip ' v p l 4
lng ging ca pi, v npp 0 . Khi ta gi n l di hay chu vi ca chu tuyn.
Chu tuyn i ngu:
Hai chu tuyn C= v C= c gi l
hai chu tuyn i ngu ca nhau nu v ch nu:
ji sao cho Pi v Qj l 8 lng ging ca nhau
Cc im Pi l nh th Qj l nn v ngc li.
Chu tuyn trong:
Chu tuyn C c gi l chu tuyn trong nu v ch nu:
Chu tuyn i ngu C ca n l chu tuyn ca cc im nn.
di ca chu tuyn C nh hn di ca chu tuyn C
Chu tuyn ngoi:
Chu tuyn C c gi l chu tuyn ngoi nu v ch nu:
Chu tuyn i ngu C ca C l chu tuyn cc im nn
di ca chu tuyn C ln hn di ca chu tuyn C
T nh ngha, ta thy chu tuyn ngoi ca mt i tng l mt a gic
c dy bng mt bao quanh i tng.
2.1.2 Phng php tch d ngng t ng
( )gh : l tng s mc xm g
Gi: ( ) ( )
=gi
ihgt
Trong : P S im nh c xt= m*n
G S mc xm c xt
Gi( )
( )
( ) ( )
=
=
=
=
g
i
g
i iiPgt
iih
gm0
0l gi tr trung bnh cp xm g
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( )( )
( )( ) ( )[ ] 11 2
= Gmgm
gtP
gtgf
( )gfmaxarg= vi 1-Gg0
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Vi dx l khong cch gia cc im theo hng x (khong cch tnh
bng s im) v tng t vi dy. Trn thc t ngi ta hay dng vi dx= dy= 1
Vi mt nh lin tc f(x, y), cc o hm ring ca n cho php xc nh
v tr cc b theo hng ca bin. Thc vy, gradient ca mt nh lin tc, c
biu din bi mt hm f(x,y), dc theo r vi gc , c nh ngha bi:
dr
dy
y
f
dr
dx
x
f
dr
df
+
= = fxcos + f ysin
Ch : khi ta ni ly o hm ca nh nhng thc ra ch l m phng v
xp x o hm bng cc k thut nhn chp (php cun). Do nh s l tn hiu
ri rc nn o hm khng tn ti
K thut Gradient s dng mt cp mt n H1 v H2 trc giao (theo 2hng vung gc). Nu nh ngha g1, g2 l gradient tng ng theo 2 hng x
v y, th bin ca gradient, k hiu l g ti im (m,n) c tnh theo cng
thc:
A0= g(m,n)= ),(),( 2221 nmgnmg + (1)
)),(/),((tan),( 121 nmgnmgnm = (2)
Ch : gim tnh ton, cng thc (1) c tnh gn ng bi:),(),(
210nmgnmgA +=
Cc ton t o hm c p dng l kh nhiu, y, ta ch xt mt s
ton t tiu biu: ton t Robert, Solbel
*)K thut Robert
Vi mi im nh I(x,y) ca I, o hm theo x, theo y c k hiu
tng ng bi gx, gy c tnh:
+=
+=
),()1,(
),(),1(
yxIyxIg
yxIyxIg
y
x
iu ny tng ng vi vic chp nh vi 2 mt n H1 v H2:
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=
01
10
1
H
=
10
01
2
H
Qu trnh tnh ton c thc hin qua cc bc sau:
Bc 1: Tnh xx HII = v yy HII =
Bc 2: Tnh 22 yx II +
T ma trn22
yxII +
chn ra cc im cao th 2, hoc th 3.. chim a s*)K thut PreWitt:
K thut ny s dng hai mt n H1 v H2:
=101
202
101
1H
=121
000
121
2H
Qu trnh tnh ton c thc hin qua 2 bc:
Bc 1: Tnh xHI v yHI
Bc 2: Tnh xHI + yHI
*)K thut Sobel:
Tng t nh k thut PreWitt, k thut Sobel s dng 2 ma trn mt n
nhn chp l:
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=
101
101
101
1
H
=
111
000
111
2
H
2.2.2. K thut Laplace:
Cc phng php nh gi Gradient trn lm vic kh tt khi m
sang thay i r nt. Khi mc xm (gi tr ti mt im ca nh ) thay i chm,
min chuyn tip tri rng, th ta c phng php Laplace (o hm bc hai) c
hiu qu hn. Ton t Laplace c nh ngha nh sau:
2
2
2
22
dy
f
dx
ff
+
=
Vy suy ra ta c:
( ) ( )( )( ) ( )[ ] ( ) ( )[ ]yxfyxfyxfyxf
x
yxfyxf
x
f
xx
f,1,,,1
,,12
2
+
+
=
( ) ( ) ( )1,,2,1 ++= yxfyxfyxf
Tng t ta c:
( ) ( ) ( )1,,21,2
2
++=
yxfyxfyxf
y
f
Ton t Laplace dng nhiu kiu mt n khc nhau xp x ri rc ohm bc 2. Di y l 3 kiu mt n hay dng:
=
010
141
010
1H
=
111
181
111
2H
=
121
252
121
2H
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Qu trnh tnh ton c thc hin qua cc bc sau:
Bc 1: IH
Bc 2: ( )yxIH ,
Bc 3: Tch ngng
ngha hnh hc:
( ) ( ) ( ) ( ) ( )2,11,21,),1(1,14, ++++++++= yxIyxIyxIyxIyxIyxIH
= I(x+1, y+1)- I(x+1, y)
+ I(x+1, y+1)- I(x, y+1)
+ I(x+1, y+1)- I(x+2, y+1)
+ I(x+1, y+1) I(x+1, y+2)
( ) ( ) ( ) ( )x
yxI
y
yxI
x
yxI
y
yxI
++
++
++
+=
1,11,11,,1
( ) ( )2
2
2
2 1,11,1
y
yxI
x
yxI
++
++= I2=
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2.3 Pht hin vng cha bin s xe
S cc bc c m t trong hnh di
nh u vo: l mt nh c 256 mc xm, c nh phn ha thnh nh
nh phn. Mc ch ca giai on nh phn ha nh l nhm lm ni bt vng
bin s xe. Khi ta tch bin, vng bao ca bin s xe s hin ln r rng. Sau
dng phng php pht hin bin c c bin dc vo ngang ca nh. Ktqu ca cng on ny, nh thu c l nh nh phn ch cha cc cnh dc v
ngang. Thc hin bin i Hough cho cc on bin va ly c v xc nh
cc on thng i qua tp cc im bin ca mi bin, kt qu s l cc on
thng ngang v dc. Giao ca nhng on thng ny s cho ra vng con I c
2.3.1. Nh phn ha nh
nh ban u c s dng l nh 256 mc xm. Vic s dng nh 256
mc xm khng lm gim i tnh a nng ca ng dng. Trn thc t, nh 256
mc xm vn c s dng nhiu, v nhiu thit b ghi hnh cng c kh nng
t chuyn nh mu thnh nh 256 mc xm. Tuy nhin, nu nh 256 mc
xm th vic pht hin bin khng hiu qu, v s thay i lin tc ca cc mc
xm lm cho vic xc nh bin khng phi d dng, v vic tm ra cc vng lin
tc ca bin kh hn ch. V vy, chng ta thc hin chuyn nh v dng nh
phn thc hin vic ly bin nhanh hn.
32
nh u vo
Nh phn ha
Tch bin
Bin i Hough
Thu c vng con Ic
Hnh 2.1: S gii quyt
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void Binarize// Nh phn ha nh
{
// nh u vo: nh 256 mc xm
// u ra l nh nh phn
P: l tng s im nh c xt (m,n)
g(j,j) tng ng l mc xm ca im nh I(i,j)
: l ngng ca nh c xc nh theo phng php trn.
for(int i= 0; i< m; i++)
for(int j= 0; j< n; j++)
if(g(i, j)
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=
101
202
101
1
H
=
121
000
121
2
H
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Void BoundaryDetach()
{// Tch bin ca nh
// nh u vo: nh 256 mc xm
// u ra l I(i, j)
P: l tng s im nh c xt (m,n)
g(j,j) tng ng l mc xm ca im nh I(i,j)
: l ngng ca nh c xc nh theo phng php trn.
// Trc ht tnh hai ma trn nh theo trc dc x v ngang y
Ix = H1* I, Iy = H2* I
for(int i= 0; i< m; i++)
for(int j= 0; j< n; j++)
I(I,j)= Ix(I, j)+ Iy(I, j);
}
Kt qu thu c , mt nh cnh dc Ix v mt cnh ngang Iy. C th xem
nh di vi phng php Sobel.
2.3.3 Bin i HOUGH
Bin i Hough l phng php dng xc nh ng thng (ng
trn elip) gn ng i qua mt tp hp im.
Vi (x,y) l mt im cmxy += ymxc +=
Nh vy nu c N im nm trn 1 ng thng
=
=+
Ni
ycm x ii
,1
=
=
Ni
mxyc ii
,1Thay v tm N im trn ng thng, ngi ta xt tt c cc im, xem
im no c nhiu ng thng i qua nht
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Thc cht bin i Hough l bin im thnh ng thng
[ ][ ]
[ ][ ] ++
=
cmathimxyc
tmcmyx
cmcma
ii
ii ,,
,0
Sau m trn ma trn
Hn ch: h s m th lu [ ]cm
a
1
1m th lu [ ][ ]cma
36
C= y2-x
2m
C= y1-x
1m
Hnh 2.2 Trc ta cc i qua 2 im
Hnh 2.3. Trc ta cc
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Bin i Hough theo ta cc
Cc im trn ng thng c ta cc t/m sin.cos. yxr += vi
3600 v2
22NM
r+
vi M v N l chiu cao v chiu rng ca nh
Ly ti tm nh
[ ][ ]
( )
[ ][ ] ++
=
rathi
yxrneuyx
r
rar
sincos,
,
0,
Bin i Hough nh x N im ny thnh N ng sin trong ta cc
m cc ng ny u i qua im ( iir , ). Giao im ( iir , ) ca N ng sin
s xc nh mt ng thng trong h ta cc. Nh vy, nhng ng thng
37
(x,y)
r
x1,y1
x2,y2 Bin di Hough
( )iip,
Hnh 2.5. ng thng Hough trong ta cc
Hnh 2.4: H ta cc
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i qua im ( )ii yx , s cho duy nht mt cp ( iir , ) v c bao nhiu ng qua
( )ii yx , s c by nhiu cp gi tr ( iir , ). Mc ch l tm ra cp ( ),r sao cho
s ng hnh sin i qua nhiu nht, v cp chnh l cp tham s cho ng
thng2.3.4Trch chn on thng v tnh giao im
Sau khi xy dng cc ng thng Hough, chng ta thu c hai tp
ng thng: tp ng thng dc v tp ng ngang cc nh nh phn cnh
dc v ngang. Tip theo, chng ta xc nh giao im ca cc ng ny ny
to thnh cc vng con l cc t gic c kh nng cha bin s xe. Tuy nhin,
lng vng con c c l rt nhiu. Do vy, chng ta thay v tnh giao im
ca cc ng thng, m chng ta s thc hin vic tnh giao im ca cc on
thng. Cc on thng chnh l cc on i qua tp hp im c xc nh
thng qua ng thng Hough. Vic xc nh cc on thng ny l n gin
thng qua hai u mt ca on thng. Mt cch n gin, ta c th xem u
mt trn (hoc bn tri) l im trong tp hp im nm trn ng thng
Hough c tng ta theo trc x v y l nh nht. im u mt di (hoc
bn phi) l im nm trong tp hp im nm trn ng thng Hough c tng
ta theo x v y l ln nht. m bo rng cc ng thng dc, ngang (t
nh cnh dc, ngang) c th ct nhau nh trong thc t, chng ta cn m rng
cc on thng v hai hng mi on 5 im. Nh vy on thng m chng ta
s dng so vi on thng thc t sx di hn nhiu hn khong 10 im. Kt
qu ca php bin i Hough va trch chn on thng c m t trong hnh
di
Vic tnh giao im ca cc on thng l kh n gin. Chng ta ch cn
tnh giao im ca cc ng thng Hough v kim tra xem giao im cao
nm trn on thng c trch ch ra hay khng. Giao im ca cc on thng
s l cc vng con Ic c kh nng cha bin s xe.
Kt qu ca phn trn cho chng ta mt tp cc vng con Ic l cc t gic.
n y, chng ta c th khng nh bi ton trn chnh l thc hin theophng php bin i Hough. Tuy vy, im khc bit (cng l im tin b)
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ca phng php trnh by trong tiu lun ny l: phng php bin i Hough
ch dng li bc ny, v sau thc hin tin hnh nhn dng cc k t trong
cc vng con ngay. Vic nhn dng c th c nhiu phng php khc nhau,
nhng vi mi vng con ang cn mt lng kh ln. Vy trong bi tiu lun
ny em khng ch dng li trong vic tm ra cc vng con Ic, m tm tip nhng
vng con c xc sut cha bin s xe, loi i nhng vng m kh nng tn ti
ca bin s xe l rt t. Vy c, tp cc vng con I c c thu hp, lm cho khng
gian bi ton nhn dng thu hp li. V vy, cch gii quyt ny tr nn nhanh
hn, hiu qu hn cch tip cn bin i Hough, khng ph thuc nhiu vo
khng gian nh u vo.
2.3. Xc nh chnh xc vng cha bin s xe
Kt qu ca bi ton trn a ra tp cc vng con I c c kh nng cha
bin s xe. Cc vng con ny l cc t gic. Tuy nhin, s lng cc vn con Ic
l khc nhiu, cha th m bo chnh xc vng no cha bin s xe thc
hin vic cui cng l nhn dng nh. V vy, phi loi b i nhng vng con
trong Ic khng c kh nng cha bin s xe.
S thc hin bi ton ny:
39
Vng con Ic
Bc ban u
Tiu ch v chiu rng v cao
Tiu ch s k t
Vng con Ib
Hnh 2.6: S thc hin bi ton ny
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2.3.1. Bc ban u:
Ta bit: Bin s xe trn thc t c hnh dng l hnh ch nht. V vy, khi
chp nh ca bin s xe s c dng ta hnh bnh hnh. Trng hp ti u l nh
hnh ch nht. Do , trong qu trnh xt duyt cc vng con Ic, nu hnh no
khng c hnh dng ta hnh bnh hnh th c th loi b ngay m khng cn
tnh n. Ta c th xem hnh t gic ta hnh bnh hnh c nhng c im sau:
Cc gc khng c nh. C th ly ngng l 045
Hai gc i khng chnh lch qu ln. Ly ngng 030
Bin s xe phi c mt din tch no , v ln c th nhn din ra
k t tn ti trn . V vy, nhng vng con c din tch nh hn mt ngng
no , th loi b ngay v ch kch thc chiu di v rng ca vng con icI .
Vy th chu vi ca vng con nh hn ngng no th c th loi b ngay
Void Filter
{
// u vo l tp vng con Ic
// u ra: tp vng con 'cI
// l ngng v chu vi
// Perimeter( icI ) l chu vi ca mi vng con Ic
// N l s vng con
For(int i=0; i< N; i++){
If(Perimeter( icI ) > )
// Caclulate goc A,B,C,D ca mi vng con icI
If( A && B && C && D tha mn ngng)
Copy( 'ic
I , icI )
}
}
Sau khi loi b i nhng vng con theo hai tiu ch trn, chng ta thu
c tp con 'cI . V thc t bin s xe c hnh ch nht, nn ta c th dng
php tnh tin, php quay, php t l a cc vng con 'cI thnh cc hnh ch
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nht. L do a cc hnh t gic thnh hnh ch nht v bin s xe c dng
hnh ch nht, cc k t nm trong vng bin s xe vung gc vi cnh di ca
hnh ch nht. Khi thu c nh, c nhiu nguyn nhn lm cho nh bin s xe
b nghing. Ko theo , cc k t cng b nghing theo, lm cho vic nhn
dng tr nn khng chnh xc. Vic nn t gic tr li thnh hnh ch nht v
cng nn cc k t tr nn thnh ng. V khi tr thnh hnh dng ch nht, th
bin s xe mi th hin r tnh t ln chiu di/rng. V ta c cc tiu ch di
y.
2.4.2 Tiu ch t l chiu di/rng.
Vi mi quc gia, th bin s xe c kch thc nht nh. V th hin
thng qua t l gia cc cnh. V d vi bin s xe nc ta: vi bin s c mt
hng th t l nm trong khong 5.45.3 HW v vi bin s xe c hai hng
th t l l 4.18.0 HW . V kt qu ca tiu ch t l chiu di/rng l thu
c mt tp con ca 'cI cha bin s xe. Vy ta c gii thut
Void RatioWH
{
// u vo l tp con 'cI
// u ra l tp con ''cI ca'
cI
// Gi edge_ratio= t l chiu di/rng
// l ngng chiu di/rng [0.8,4.5]
For(int i=0;i< N;i++)
{
Int m= edge_ratio( 'ic
I )
If(m [0.8,4.5] )
Copy( ''ic
I , 'ic
I )
}
}
Kt qu: tp cc vng con ''ic
I c kh nng cha bin s xe. Vi s vng
con nh hn hn s vng con ma ta thu c ban u trong bin i Hough.
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2.4.3 Tiu ch s k t trong vng bin s xe
Vi mi nc th s k t trong bin l khc nhau. nc ta, s k t
trong bin s xe thng l 6,7,8 tng ng i vi cc xe qun i, xe my c
v xe t, i vi xe my by gi.
Mi k t c cc c trng sau:
85.033.0 Height
22.0Width
T ta c ngng s dng l [6,8]
Void Character
{
// u vo tp vng con ''ic
I
// u ra tp vng con '''ic
I
// N l tng s vng con ca ''ic
I
For(int i= 0; i< N; i++)
{
Vi mi vng con''
icI
- Tm vng lin thng ca mi ''ic
I
- Lu cc thng s v chiu rng, cao ca mi vng lin thng
If(tha mn ngng ) th tin hnh nhn dng
}
}
Kt qu nu tm c bin s xe u tin tha mn, chng ta c th dngthut ton ngay v chuyn sang bc 3 l nhn dng k t. Nu tm tt c cc
bin s xe tn ti trong nh, th bt buc phi duyt qua ton b vng nh.
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Chng 3:
BI TON NHN DNG K T
3.1 Tng quan v nhn dng
Nhn dng l qu trnh phn loi cc i tng c biu din theo mtm hnh no v gn cho chng vo mt lp (gn cho i tng mt tn gi)
da theo nhng quy lut v cc mu chun. Qu trnh nhn dng da vo nhng
mu hc bit trc gi l nhn dng c thy hay hc c thy (supervised
learning); trong trng hp ngc li gi l hc khng c thy (non supervised
learning). Chng ta s ln lt gii thiu cc khi nim ny.
3.1.1 Khng gian biu din i tng, khng gian din dch
*)Khng gian biu din i tng
Cc i tng khi quan st hay thu thp c, thng c biu din bi
tp cc c trng hay c tnh. Ngi ta thng phn cc c trng theo cc loi
nh: c trng t p, c trng hnh hc v c trng chc nng. Vic biu din
nh theo c trng no l ph thuc vo ng dng tip theo.
y ta a ra mt cch hnh thc vic biu din cc i tng. Gi s
i tng X (nh, ch vit, du vn tay, v...,v) c biu din bi n thnh phn
(n c trng): X = {x1, x2,..., xn}; mi xi biu din mt c tnh. Khng gian
biu din i tng thng gi tt l khng gian i tng X c nh ngha:
X = {X1, X2,..., Xm}
trong mi Xi biu din mt i tng. Khng gian ny c th l v hn.
tin xem xt chng ta ch xt tp X l hu hn.
*)Khng gian din dch
Khng gian din dch l tp cc tn gi ca i tng. Kt thc qu
trnh nhn dng ta xc nh c tn gi cho cc i tng trong tp khng gian
i tng hay ni l nhn dng c i tng Mt cch hnh thc gi l
tp tn i tng:
= {w1, w2,...,wk} vi wi, i = 1, 2,..., k l tn cc i tng
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Qu trnh nhn dng i tng f l mt nh x f: X ---> vi f l tp
cc quy lut xc nh mt phn t trong X ng vi mt phn t trong . Nu
tp cc quy lut v tp tn cc i tng l bit trc nh trong nhn dng ch
vit (c 26 lp t A n Z), ngi ta gi l nhn dng c thy. Trng hp th
hai l nhn dng khng c thy. ng nhin trong trng hp ny vic nhn
dng c kh khn hn.
3.1.2 M hnh v bn cht ca qu trnh nhn dng
3.1.2.1 M hnh
Vic chn la mt qu trnh nhn dng c lin quan mt thit n kiu m
t m ngi ta s dng c t i tng. Trong nhn dng, ngi ta phn
chia lm 2 h ln:
- H m t theo tham s
- H m t theo cu trc.
Cch m t c la chn s xc nh m hnh ca i tng. Nh vy,
chng ta s c 2 loi m hnh: m hnh theo tham s v m hnh cu trc.
M hnh tham s: s dng mt vct c t i tng. Mi phn t
ca vct m t mt c tnh ca i tng. Th d nh trong cc c trng
chc nng, ngi ta s dng cc hm c s trc giao biu din. V nh vy
nh s c biu din bi mt chui cc hm trc giao. Gi s C l ng bao
ca nh v C(i,j) l im th i trn ng bao, i = 1, 2,..., N (ng bao gm N
im).
Gi s tip :
x0 =1
1N i
N
=
xi
y0 =1
1N i
N
=
yi
l to tm im. Nh vy, moment trung tm bc p, q ca ng bao
l:
pq =1
1N i
N
= (xi-x0)p
(yi-y0)q
(7.1)
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Vct tham s trong trng hp ny chnh l cc moment ij vi i=1,
2,...,p v j=1, 2,...,q. Cn trong s cc c trng hnh hc, ngi ta hay s
dng chu tuyn , ng bao, din tch v t l T = 4 S/p2, vi S l
din tch, p l chu tuyn.Vic la chn phng php biu din s lm n gin cch xy dng. Tuy
nhin, vic la chn c trng no l hon ton ph thuc vo ng dng. Th
d , trong nhn dng ch (s trnh by sau), cc tham s l cc du hiu:
- s im chc ba, chc t,
- s im chu trnh,
- s im ngot,
- s im kt thc,
chng hn vi ch t c 4 im kt thc, 1 im chc t,...
M hnh cu trc:Cch tip cn ca m hnh ny da vo vic m t
i tng nh mt s khi nim biu th cc i tng c s trong ngn ng t
nhin. m t i tng, ngi ta dng mt s dng nguyn thu nh on
thng, cung, v,...,v. Chng hn mt hnh ch nht c nh ngha gm 4 on
thng vung gc vi nhau tng i mt. Trong m hnh ny ngi ta s dng
mt b k hiu kt thc Vt, mt b k hiu khng kt thc gi l Vn. Ngoi ra c
dng mt tp cc lut sn xut m t cch xy dng cc i tng ph hp
da trn cc i tng n gin hn hoc i tng nguyn thu (tp Vt). Trong
cch tip cn ny, ta chp nhn mt khng inh l: cu trc mt dng l kt qu
ca vic p dng lut sn xut theo theo nhng nguyn tc xc nh bt u t
mt dng gc ban u. Mt cch hnh thc, ta c th coi m hnh ny tng
ng mt vn phm G = (Vt, Vn, P, S) vi:
- Vt l b k hiu kt thc,
- Vn l b k hiu khng kt thc,
- P l lut sn xut,
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- S l dng (k hiu bt u).
3.1.2.2 Bn cht ca qu trnh nhn dng
Qu trnh nhn dng gm 3 giai on chnh:
- La chn m hnh biu din i tng.
- La chn lut ra quyt nh (phng php nhn dng) v suy din qu
trnh hc.
- Hc nhn dng.
Khi m hnh biu din i tng c xc nh, c th l nh lng
(m hnh tham s) hay nh tnh (m hnh cu trc), qu trnh nhn dng chuyn
sang giai on hc. Hc l giai on rt quan trng. Thao tc hc nhm ci
thin, iu chnh vic phn hoch tp i tng thnh cc lp.
Vic nhn dng chnh l tm ra quy lut v cc thut ton c th gn
i tng vo mt lp hay ni mt cch khc gn cho i tng mt tn.
*)Hc c thy (supervised learning)
K thut phn loi nh kin thc bit trc gi l hc c thy. c im
c bn ca k thut ny l ngi ta c mt th vin cc mu chun. Mu cn
nhn dng s c em snh vi mu chun xem n thuc loi no. Th d
nh trong mt nh vin thm, ngi ta mun phn bit mt cnh ng la, mt
cnh rng hay mt vng t hoang m c cc miu t v cc i tng .
Vn ch yu l thit k mt h thng c th i snh i tng trong nh
vi mu chun v quyt nh gn cho chng vo mt lp. Vic i snh nh
vo cc th tc ra quyt nh da trn mt cng c gi l hm phn lp hay hm
ra quyt nh. Hm ny s c cp trong phn sau.*)Hc khng c thy(unsupervised learning)
K thut hc ny phi t nh ra cc lp khc nhau v xc nh cc tham
s c trng cho tng lp. Hc khng c thy ng nhin l kh khn hn.
Mt mt, do s lp khng c bit trc, mt khc nhng c trng ca cc
lp cng khng bit trc. K thut ny nhm tin hnh mi cch gp nhm c
th v chn la cch tt nht. Bt u t tp d liu, nhiu th tc x l khcnhau nhm phn lp v nng cp dn t c mt phng n phn loi.
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Nhn chung, d l m hnh no v k thut nhn dng ra sao, mt h
thng nhn dng c th tm tt theo s sau:
Hnh 3.1: S tng qut mt h nhn dng.
3.2 M hnh mng nron nhn to
Mng nron nhn to (Artificial Neural Network) bao gm cc nt (n
v x l) c ni vi nhau bi cc lin kt nron. Mi lin kt km theo mt
trng s no , c trng cho c tnh kch hot gia cc nron. C th xem
trng s l phng tin lu gia thng tin di hn trong mng v nhim v
ca qu trnh hun luyn (hc) mng l cp nht cc trng s khi c them ccthng tin v cc mu hc, hay ni cch khc, cc trng s c iu chnh sao
cho ng.
Trong mng, mt s nron c ni vi mi trng bn ngoi nh cc
u ra, u vo
3.2.1 M hnh nron nhn to
Trch chn ctnh biu din
i t ng
Phn lp raquyt nh
nhgi
Qu trnh ti n x l Khi nhn dng
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Hnh 3.2: M hnh nron nhn to
Mi nron c ni vi cc nron khc v nhn c cc tn hiu sj t
chng vi cc trng s wj. Tng cc thng tin va c trng s l:
Ngi ta gi y l thnh phn tuyn tnh ca nron. Hm kch hot g
(cn gi l hm chuyn). ng vai tr bin i t Net sang tn hiu u ra out.
y l thnh phn phi tuyn ca nron. C 3 dng hm kch hot thng
c dng trong thc t
*)Hm dng bc:
( )