discriminant analysis quickbird multispectral panchromatic
TRANSCRIPT
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Article
Segmentation and Classification with Discriminant Analysis of
QuickBird Multispectral and Panchromatic Data to DistingriishCryptomeria J'aponica and Chamaeegparis obtusa Patches
Yasumasa Hirata*i, NaoynkiTomoaki Takahashi"'", YoshioFuruya'2,Awaya'`Atsushi
Sakai'Z,and Toru Sakai'5
ABSTRACT
Stands of CrpPtomerin jaPcmica and ChamaeopPan's obtusa haL,e different functions: in particular, diversity of
understory vegetation and preyent{on of soil erosion, but thelr distribution is not always delineated and distin-
guished en forest maps, 'Fhis
study investigated the relationsh{p between parameters in the image segmentatien
procedure for high-resolution sak/IIjte datu and generated object size in objoct-orienterl classification, and distin-
guished objects of C 1'aPonica and C obtusa by means of discriminant analysis. Thittsr-six sarnple plets were
established in Cj'mponica and C: obtttsa stands in the national forests of the Koisegawa watershed. QuickBirdpanchromatic and multispectral data was used for this study. Seginentatioii, which is the first step in object-ori-
ented class{fication, was applied to the image data of the sample plots, and species were assigned to corre-
sponding' objects generated from the image segnientation. For these objects, the aver[nge and standard deviation of
digital number for the feur rnultispectral bands und panchrematic band aiid the Nornialjzed IMfference Vegeta-
tion Index (NDVI) were calculated within them. Discriminant analysis to distinguish C,1'aPonica and Cobtttsa was
conducted using these twelve variables of average and standard deviation as independent vaidables. The correct
distinction was made for ICK)96 of CJ'aPoni(/a objects and 95.5Uh of C obtusa objects. The results clarified that it wus
possible to distingtiish C]'aPonicct and Cobtf・asa patehes using high-resolution satellite data.
KbJ,tvo}ds: CmpPtomen'a 1'aPonica, Chaniaeopan's obttrs4
tion, scale parameter
high-resolutionsatellite data, object-oriented classifica-
INTRODUCTION
In Japan, forests cover an area of about as million ha and
this estimate has remained stable for 40 vears. This constanov
of forested area is the result of the ba]ance between decreased
forest area b}, clevelopment due to expansion of urban areas
and increased area bv afforestation and/'or reforestation on
abandoned fannland due to people moving from the moun-
tains down to the towns. However, the ratio of plantation to
natural and secondary forest area has varied greatly. The
iricrease in tiinber demand for reconstruction after World WarII resulted in the conversion of natural forests to sugi (CnyyPto-men'a )'aponical and hinoki {Chantae()v)an's obtusa) plantations
in Japan, and the continuous natural forests becarne segi"en-
ted CMAITF, 20e3). Secondary forests near ui'ban areas finished
their role of providing fuel and many of them were also
eonverted te plantations. As a result, 42Yo of the forested area
or osVt/ ef the total land area is now covered with plantations
(FAO, 2oo6), fonning a mesuic of natural or secondary forests,
Correspondin.if. author/ Yasumusu HiratrAE-mail/ [email protected],jp'iBureau
of Climale Change, Forestrv and Forc/st
Products Research Institute,
1 Matsunosato, Tsukuba, 305-8os7, Japan"'
Forestry Division, Japan International Research Cen-
ter of Aghcultural Sciences,
1-1 OhwashL Tsul{uba, P,05-8686, Japan
'"Ilepartinent
of Forest Managcrmeiit, Fei'estry and
Forest }'roducts Research Institute,
1 Matsunosato, Tsukuba, :lms-Sifl87, Japan"River
Basin Research Center, Gifu University,
1-1 Yanagido, Gifu, 501-1193, JapuiiS'Research
Institute for Humanity and Nature,
os7-4 Motoyaina, Kainiga]ne, Kita-ku, Kyoto oo3-
W'n7, Japmi
f Phr Plann.1di 2Z3,284 (201 1.)
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plantations and cleur-cutting areas, Restricted movement of
aniinals and loss of biodii,ersity and genetic diversity are a
growlng concem.
In Japari, the Forest Agenc}, and loca] govenirnents has,e
prepared forest maps at the scale of Ii5,ooO and forest regis-
ters by sub-compartment as management units conceniing, for-
est distribution and attiibutes such as location, area, species,
stand age, stand volume and regulatiun. Advances in comput-
er technolog'y as well as iinproved GIS funutions in the pastseveral years have led to tlie expansion of C'TIS utilization. The
rapid constiuction of GIS data related to forest rnanagement
units, which was generated from these forest niaps and forest
reg'isters, has provided additional spatial understaridiiig, and
demonstrates great ability for planning lorest road construc-
tion and final cutting, However, some species iu/e occasionalLv
recerded for a sub-compartment in the forest register becnuse
CJ'mponica and C. obtt{sa were planted in respectively suituble
sites on a slepe, Etnd some broad-!eaved trees are found along
the valley or the ridge. "rhile the mixed proporiion {s recor-
ded in the forest rcgister for such a sub-compartment, the in-
lormation on species distribution is not delineated on the
forest map. Stands of CJ'oponica and C vbtttsa have different
functiens/ in particular, diversity of understory vegetation und
prevention of soil erosion: therefore, the spatial understanding
of their distribution is hnportant.
In the application ol remote sensing to i'orestry, forest typemapping is essential in teinis of sustainable forest !nanage-
ment and ecologica] consewation, and has been required first
and foremost since the launch of the fhst Earth obsenration
satellite. Conventional remotely sensed dtita, such as from
Landsat and SI'OT satellites, has been used for forest typemapping making use of the differenoe in refiectance propenies
of the forest canopies (for eocample. WooDcooK et at., 1994; Jm);Get aL, 2C()4; GJERTsEN, 2oo7), However, there has been an issue
about the mixture of different forest or land-cover types in a
pixel leadin.as to misclassification in the case of a complex for-
est stand shape or s]nall stand area in comparison with the
pixel size of remotely sensed data.
The new generation of commercial high-resolution satellite
data with ground resolution finer th[m 1 × 1m such as IKONOS
and QuickBird opened a new era in digital analysis of forest
stand attributes. High-rcso]ution satellite data has almost the
smne spatial resolution as a conventienal aerial photograph, and
it {s possible to use the image for interpretation as an aeidal
photograph. In addition, high-resolution satellite data has a
wider d}ma!nic range than conventional satellite data accord-
ing to the degree of sensor sensitii,ity (HIRixT.1, 20C)9). These
advantag'es of high-resolution satellite data might make it
possible to distingniish stands of different age and species, On
the other hand, the irreguluidty of reilectance from the canop},
surface appears within a domain where the refiectance proper-
ty is regarded as unifonn (]L(uRAKAs{i, 2CD4), making it difficult
to apply conventional pixet-based classification to hi.orh-reselu-tion satellite data.
Jfiiuta et aJ.
Recentiy, the new "obj'ect-eriented''
classification method has
been used instead of pixel-based classification. Objoct-eriented
dassification is effectivc in segmentiiig aii area that consists of
varieus land-cover t}rpes into objects with extensions of simi-
lar properties (Li'u{oNAcA et aL, 2oo8). Previous studies have
app]ied this approach for land cover and forest rnapping us-
ing conventional satetlite data such as Landsat or SI'O'['
(GENELE'r'r[ and GoRTE, 20e3; HA[.L et aL, 2004; BocK et aL, 2005;
HAy et al., 2oo5; CoNcHEDDA et al., 2008) as ",ell as hi.uh-resolu-
tion satellite data such us IK()NOS or QuickBird (vAN Coll.LIEet al., 2oo7; Lvth・IoNAcA et aL, 2oo8: MixRTINEz-MoRA[.]r.s et al.,
2008}, 'l'he
object-eriented approach rnakes it possible to devel-
op a classificatien strategri that. employs sl)atial relationships
between ol]jects in addition to specti'al inferniation (PLAT'r and
SC}IoEN]gAGEI., 2oo9).
'1'he
ebject-oriented classification approach consists of tu,o
proccdures: image segmentation into objects and classification
of generated ebjects. This study investig.ated the relationship
between parameters i]i the irnage segmentation proceclure for
high-reselution satellite data and generated object size, and
d{stinguished objects of C1'aPonica and C, obtttsa by means of
discrimin[mt analvsis.
MATERIALS AND METHODS
Study Area and Samp]e Plots
The study area was located in the Koisegawa watershed,
Ibaraki prefecture, Japan {36'7'20'-ea'19'21"N, 14U'6'22"-1co'18'FS"
E, WGS M), which is an area of 2sa.5 kni". The watershed is
surrounded by Mt, Tsukuba, Mt. Ashio, Mt. Kaba Mt. Nan-
tai and rvft. Wagakuni, and farmland spreads out on the plain
below 10() m above sea level. Orchm'c[s are found around the
foot of the meuntuins, alld natural forests, secondary forests
and plantations are distributed north and west of the water-
shed, forrning a mosaic pattern.
The naticmal forests in thc watershed, which are maTiaged
t)v the fbaraki District Forest Office, were the targets of tliis
study. These forests cover an area of 1,8ee ha and plantations
occupy 7UV・i of the forests. The forests consist o[ plantations ot'
C.icipo}7ica and Cobtusa, broad-leaved forests, mixed foresbs and
smal1 patches of conifer species,
A total of ss circular sarnple p]ots of e.04 ha each were
cstablished in the stands, which ranged in age from 15 to 93
years {Fig. 1, Table 1). Fourteen plots were set up in C]'mponi-
ca stands Emd 22 plots in C obtusa stands. The coordinates at
the center of all saniple plots were positioned by DGPS for
supetimposing on high-resolution satellite data, DBH of all starid-
ing trees in thc sainple plots was measured and species were
recorded. Stand density jn the sample plots was calculated from
the number of standing trees per O.O'1 ha. Mcan DBH of sam-
ple plots ranged from 13.9 to 37.2 cm and stand density from
475 to 2,8oo trees/ha. Tree height ol inere than 40glo' of the stancl-
ing trees was measured in each sample plot Emd the (}thers were
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Sagmevttatinn and Classification t{itk lh'scn'mi}tant Analysi qt'QuickBint,lfi{ttk'Pex,tral and funchromcttic Data to Dds'ting"tsh Cryptomen'a j'aponica aiui Chainaeq}pari obtxtsa thtches 275
Fig.1
Q spom rm ww
Distribution of sarnple plotsTwo plots of Crp,Pfvnten'(i 1'aPonica with asterisk(n')were located in the
Chaswaet.mparis obtasa was dominant.
Table 1 Number of sample plots 1]y stand age
st
sub-compartinent where
class
Stand age dass Cyears) -20 21-30 31-・10 ・11-50 51-60 61- Total
C. 1'aPonica
C. obtz{sa
Total
2o2 o66 41014 325 4o4 145 142236
estiinated from the NdsIund forniula (NksuDgD, 19sa). The stand
height in the sarnple plots varied from 9.6 to li.8 m.
Sate11ite Data and GIS Data
QuickBird panchromat{c and multispectral data was ac-
quired on 27 February 2oo3. The spectral bund of panchromaV
ic data ranges from 450 to seO nm, and the spatial i'esolu-
tion is O.61 m at the nadir. Multispectral data consists of [our
separate spectral bands: blue (,lso-520 nm}, green (520-6oo nm),
red (630-6oo nm) and near infrared (760-910 nm), Emd tliey all
have 2.44-m spatial resolution at the nadir (DIGITi'll.GLoBE, 2oo6).
The data was geo-registered to the Universal Transverse Mer-
cator (UTM} coordinate system (WC]S an, Zone 54) with O.7-m
and 2.8-rri spatial resolution, respectiL,ely, using the neurest
neighbor method for resarnpliirg' to maintain the c)riginal re-
fiectance properties.
GIS data for the study area was generated from 1:5,Ooo
forest maps and digital forest registers compiled by the Kanto
f Fbx Plann. i6'2Z3'284 (201O
Regional Forest Office to establish sarnple plots and confirm
their stand age. This data was also used to gee-register
QuickBird data using forest type information.
Iniage Segmentation
Segmentation in the object-eriented approach is charucter-
ized by the integrated use of spectral and texturaHnformation
in uomparison to the single use of spectral jnfonnation in
conventional pixel-based classification, We investigated the
effect of the paranieter concerning heterogeneity in segrnenta-
tion in the object-oriented approach, on the number and aver-
age size of generated objects, The segmentatien of high-reselu-
tion satellite data was conducted using eCogn{tion software
(DEFIN]ENs IpsrAGINg 2001) fer object-oriented classification. The
heterogeneity Ui, which is defined as the addition of weighted
values ol the heterogeneity within the spectrum (in,,E.,) and that
within the shape (h.H,,,,.), is determined by the scale parameter
in eCognition, and is cxpressed as belew:
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f= Phcoior+(1-P) k.H"pe {1)
whereOgPS1and is decided by the analyst. The scaLe pa-
rameter relates the minimum size required to {dentiS, a par-
ticular objcwt, which depends on the resolution of the images.
Thei'e are twe other parameters: the heterogeneity of corri-
pactness (h,..,,.,t) and that of smeothness (lr..,,.,ih), which are
determ{ned by the analyst The heterogeneity within the shape
is dafined as the addition of their weighted x,alues.
h,h.p,- --
qh...p,.t +(1-q) I't..,,,,,h (2)
whereO '1( q<- 1 nnd is decided b}, the ana]yst. We investigated
the number and the average size of generated objects by scaleparameter fixing h,..,..t and h,.../h io CO.1, O.9), (O.5, O.5) and (O.9,
O.1), respectively.
Extraction of Plantations
In the study area, there were severat forest types such as
plantations ef C 1'aponica and C obtusa, broad-leaved forests,
mixed forests and small patches of conifer species. As the small
patches of conifer species were foundi only around the top of thc'.
mountains, only the broad-leai,ed forests and mixed forests
nee.ded to be distinguished from the plantutions. We prepared
the high-resolution satellite data in the leafless season for the
sake of Iacilitation. The Normalized Difference Vegetation ln-
dex (NDVI), which was one of the indiccs representing the
condition of vegetation, was calculated irom the red band (Band3) and infrared band (Band ,D as below:
NDVI =(Band4 -
Band 3) ,t (Band4 + Band 3} (3)
NDVJ was calcu]ated for the study area using QuickBird mul-
tispectral data.
The average NDVI was calculated for eauh object genera-
ted by image segmentatien. We used only those objects that
were included in the sub-compatunents of one forest type.
QuickBird panchromatic data as well as multispectral data was
used Ior image segnientation. The spatial resolution, nannely
pixel size, was dilferent: O.7 and 2.8 m. On the other hand,
NDIq was calculated using multispectral data; therefore, sorne
NDVI pixels within the beundaTy of objects included two dil
ierent ±'orest
types. In this analysis, we used only NDX・a pixelsthat were comp!etely included in the objects to calculate the
average. We compared the average NDVI b}, object in the
plantations with that in the broad-lcaved forests and mixed
forests.
Discriminant Anal},sis
In Japan, CJ'aPonica and C obtusa trees are often planted
in the same sub-compartment, and infonnation on their distri-
bution is not available. The distinction between CJ'mpeni(/a and
Hiruta et aL
C. obtusa patches was examined by means of discriminant
analysis. Obj'ects, which included sample plots, were used for
this analysis. The average and standard deviation in digital
number of panc/hrematic data and that ef the four bands of
multispe{Jtrul data for these obiects were calculated. The aver-
age and standard deviation of NDVI were also used for the
analysis. We cenducted the discriminant analysis using these
tu,elve averages and standaT'd deviations lor eaeh eb]'ect as
independent variables.
Test for Equality
While the forest type of generated objects can be con-
fimied by field surve},, another method is required for the
assessment of segmentation in comparison with the method for
assessing the results of conventional pixel-based dassification.
Verification of the accuracy of pixel-based elassifieatien
is conducted by pixel at a point where the forest type can be
collfirmed; however, in objeet-oriented classification, the
beundaries of objetrts, namely the segmentation results, are
inlportant.
In Japan, forest managemcnt units consist of compart-
ments and sub-compartments, and they are administered usiiig
forest registers and foi'est maps. Forest patches of the same
forest type are normally smaller tban a sub-compartment. The
boundaries of these forest patches are not delineated in forest
maps, but the proportion of each forest type in a sub-cem-
partment is recorded in the forest i'egisters fi'oin field observa-
tion. Therefore, the proportion of area by forest type obtained
from the forest register and that obtained from object-
oriented classifieation were cempared by cempartment. All
objects for the study area that were obtained from image
segrnentation were classified into broad-leaved and mixed for-
ests, CJ'tiPonica, and C obtusa using the coetT{cients ancl con-
stants of the linear discriminant function that were obtained inthe above analysis. Thc total area of objects of the same for-
est type was generated by compartment. Finally, six compart-
ments were used for the test for equality between proportionsof area by species obtained frern the forest register and those
obtained from object-oriented classification in a compartment,
and three coinpartments in the study area were excluded fromthe test due to cleud infiuence.
RESULTS AND DISCUSSION
]mage Segnlentntion
The results of image segrnentation with different scale
parameteis are shown in Fig. 2. From I;ig', 2, it is ebvious that
the choice ol scale parameter strongly effects on the generatedobject size. The relationship between scale parameter and the
number of generated objects with different ht,."pict ancl hs,nooth in
image segmenration is shown in Fig. 3. The relationship be-
tureen scale parameter and the average size of generatcd ob-
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Original
SP=60
SP=180
Fig.2
SP=80
SP=200
@DigitalGlobe,
Imagc sagrnentation with diiTerent scale
SP=100
lnc., All Rights Reserved
paraineters (SP)
f Fhr Pkinn,16・2Z3-284eOJI.)
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278 th'vata et aL
ut-oomo".o#ooE=z
20000
lsooe
aoooo
seoo
o
ow
Rvaflm
pt
ite/t///p//t/ ilt/tt/t/t//
oo,g e.1:1 O.5 O.5xO.1 O.9
O 50 100 15D 200 250
Scaleparameter
Fig. :)) The relationship between scule paramder and the num-
ber ef generated objects -,ith different h,,,,,,,,,., and h,,..o in
image segnlentation
O.8
N=-.
e.6yoooo--o
O.4¢
.ijtntomS
O.2y<o
murewtiNesE
eeh,v/ttpat/ h.nb/,o/lt
Oo.9 OM-e.s o.sxO] O.9
o so foo lso 2eo
Scaleparameter
Fig.4 The relationship between scale paraineter and the
age size of generated obJ'ects with different h,..,,.-
h...,h ill illlag'e Segr11entatioll
25e
aver-
and
25
20uto=egts5tsoE
tO-z
5
o
e.t e.5 O.9 i.3 1.7 2.n 2.5
Patch size {ha}
Fig. 5 The frequeiicy of patch size consisting of
the study area
2.9 3.3
one forest ",pe in
jects with different h...,., and J't..,.,th in image segrnentation is
shown in I;ig. 4. It is clcar lrom these figures that diflerent
weight to 1'4,,,,,,,., and iu,,,,,,,,i, did net influence the average size
or number of generated objects and only the scale paranneteraffected them. However, we should notice that these parame-
ters infiuence the shape of generated c)bjects,
The freguency of patch size consistjng of one ferest type iv
the study area obtained from the forest register, which was
arran.cred 1'rom field investigation bv foresters, is sho"m in Fig.
5. While the averuge was 1.2 ha, the niode was O.3 ha. "'hen the
aL,erage sizc of .o. enerated objects was U,3 ha, thc scale param-
eter was between 120 and l4). Therefore, it is preferable that a
smaller parameter than this, such as loo or less, is used for
extracting forest patches with Em area of around O.3 ha, and that
patches smaller than C).3 ha are integrated accordin.o to forest
type.
When the scale parumeter was 20, objects consisting of 10
to 20 trees in mature stands of Cl'aPonica were generated by thc
image segrnentation procedure, This number was rather smal-
ler than the number that AwAyA et an C2007) obtained from
IKONOS data using the sanie scEde parameter. When the scale
parameter was ,10 to 60, rnixed 1'orest patches were reasonably
evctracted, but segmentation was observed for a plantntion patchin the same stand. When the scale parameter was 80 ro 1oo,
segrnentatien of a plantation patch in the same stand was al-
so feund, as well as inequality in objects. However, results
simi!ar to the interpretation of hjg'h-resolutien satellite image
were obtained using these scale parameters. It was. therefore,
uonsidered that the segrnentation using 80 to 1oo for the scale
parameter, with which a stand of the sanie forest type was
divided into three to five objects, was practically applicable to
forest type mapping using QuickBird data.
As forest patch size depends on the forestry practice and
topographic conditions, the average size of forest patches con-
sisting of one forest ty'pe shou]d be estimated using the forest
j'egister, and a sinaller scale pm'ameter, with which ebjects
s]naller than averag'e are generated, should be used for image
segmentation. It is necessary to pay attention to the dilference
in generated obiects using different sensors with different res-
olutions and different conditions for acquiring' satellite data
such as sun angle and senser angle.
Nevertheless the effectiveness of image segrnentation in
object-oriented dassilication for cxtracting forest patches from
high-resolution satellite data, it should be recogriized that the
rcsults of segnientation do not often correspond to the bound-
aries of sub-compartments. These gaps result from the d{ffer-
eiice between segrnentation of forest cover type deT'ived froin
high-resolution satellite image and forest inanagemeni un{t. For
extunple, it is difficult to segtnent imag'e area which consists of
multiple sub-compartments of same species with similar stand
age. '1'herefore,
the results ef imag'e segmentation cannot be
used as substitution ef forest GIS data conceming forest man-
agement unit. Mutual use of them is required to understand
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Scgntentation aitri Classificatioit Lvith Lh'swiininant Analysis iV Qisif.'flBini ,lfitltisPecttnl aJsct I'anchnm!alic Data Vo Distijigvfish Cr.LPtoinen'a i[iPonica and Chamaef./l'Paiis obt!fsa lhtches
'1'able
2 Statistics on Norrna] I)ifference 1・regetation Index (NI)VI) of ebjects in broad-leavedAnixed ferests and plantations
279
Type Number of objects Mean Standard I)eviatjon Maximum Minimum
Broad-leavedf
mixed forest
PIantation
6,1152 O.44O.78 O.14O,03 O.56O.83 O.23O.70
Table 3The average
segrnentationand
standard deviation CSD.) of NDVI, inultispectral and paiichromatic dnta for the
which includes each sample plot
obiect inimage
l'lotSpecies NDVI
Average
Bandl Band2 Band3 Band4
SD. Average S.D. Average S.D. Average SJ), Averag'e SD.
Panehrematic
Average S.I).
21213212226293031323334363713,1567810ll1,1]516l7181920232425272835c.c.c.C.c.c.c.C.c.c.aC.c.c.C.c.c.c.c.c.c.c.c.c.c.c.c.c.c.c.c.c'.c.C.c.c.jaPonica.iaPonicaj'aPonica1'aPonicaJ'aPoni['aj'aPonit/a]'aPonica)'aPvnica1'aPonica.faPonica1'aPonicaj'aPvnit/a1'aPonica1'aPonicaobtusaobtusaobtt・tsaobtvfsctobtusaobtusaobtusaobtusaobtttsaobttfsavbtusctobtusaobtusaobtttsaoblttsavbtusaobtusaobtttsaobttt.saobtztsaobtt・fsaohtttsa80.278.075.976.273.978.677.578.279.076.078.078,O77.674.778,981.179.883.180.881.579.879.881.168.065.579.879.482.381.680.682.181.381.381,181.677,2 3.1
5.1
6.6
6.3
724.94.13.22.45.9
5.]5.15.28.24.62.14.3
1.8
6.I
3.24.44.2
3.89.9IL2
5.13.I
1.9
2.64.2
1.72.42.42.62.37.7
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f fox Pim・m.Ja・ 27 ?284 eOll)
Japan Society of Forest Planning
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280
ForestPlanning
present conditions ef sub-compartinenL
Extraction of Plantations
The frequency of NDV'I for objects in broad-leaved,/mixed
forests and plantations is showri in Fig. 6 and the statistics are
shown in Table 2, From Fig. 6 and Table 2, the maximurn
NDVI for objects in broad-leavedtm{xed forests was O.tt], und
the minimum NDVI for objects in plantations was U,70. As a
result, it was clear that objects in the broad-leaved/mixed for-
ests and those in the plantations could be distinguished easily
50
40e8e'
3oEB
2ogz
ao
o
Fig.6
O.2 i].3 e.4 e.5 06 O.7 G.8 O,9
NDVI
The frequency ef NDVI for objects in broad-lenved,/
mixed forcsts and plantations
Table 4 IMscriminant result between C y'aponica
Hi'tuta Et al.
{f the threshold for dividing them was set between the NDVI
maximum in broad-leaved/mixed forests and the minimum in
plantations when using the data from the leafless season,
Discriminant Analysis
The average and standard deviation (SD.) of NDVI, multi-
spectral and panchrematic data for the object in imtge seg-
mentation, which includes each sample plot, are shoum in
Table 3. Tlic results of discriminant analysis between C.
1'aPonica and Cobtvtsa are shown in Table 4, From the results
using the linear discriminant function, the percentage of cor-
rect C.j'aiponica discritnination was 100% and that for Cobtusa
discrimination was 95.5",in'. 'l'his
result indicates that stand
atttibutes of each species do not infiuence the distinction
1]etween C. 1'aPonica and C obtusa.
'l'his result amfirms that it
was possible to con'ectly distinguish between C,j'mponi(/a and C
obtvtsa objects using their corresponding spectral information,
Coefficients corresponding to the twelL,e variables and the
constants in the 1{near discriminant functien are shown in
'1'able
5. Values obtained f}'om the substitution of the average
and standard deviat.ion of panchrornatic data, feur bands ol
multispectral data and NI)VI in the objects, which includc
sarnple plots, into the linear discrim{nant function using the
coefficients and constant in Table 5 are shown in Table 6. In
Table 6, plots of Cy'apoi7ica indicates ncgative values except one
sample plot of C obtusa and other plots of C obt"sa indicate
positive values.
In this study, about ew "h ef plots' were establ{shed in stands
and C obtztsa using the ]inear discriminant function
Predicted group
C]'aPonica C. obtttsa
Total
Originaldata
Number of plotsC 1'aPonica
C. obtusa
141 o21 lg22
Rate C%) C y'aPonica
C obtttsa
100,O
・1.5
.o95.5 100.0100.0
Table5 Coefficientsand constant of the linear discriminanttunctlollin discriminant analysis between C J'aPonica and C obiusa
NI)VE.Average
NDVI S. 1).
Bandl Average
Bandl S. D.
Band2.Average
Band2 S. D.
Band3 Average
Band3 S. D.
O.936O.939
O.l54
O.588
e.621
1.198-O.195-O.197
Band4-Average
Band4 S. D.
panchro-Average
panchro-S.D.
Constant
-O.O05
-O.271
-o.e66
O.1,tl-181.446
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Sagiimiitatfon and Classijication ttitl! Piscn)niimnt Aimb/.cis of Qficmaini thtltispectrai and flonchrotpiatic Data to th'stingiiis"i
Table 6 Values obtaaned from the substitution of the average and standard
bands of multispectral data und NDVI {n the objects. which {ndude
nant function using the coefficients and constant in 'I'able
5
Co'Ptonte'ha jpmnica and evzamaeq'Paris obtitsa Flrtches
dei,iation of panchromatic data, foursample plots, {nto the linear djscrimi-
281
Plot Speeies Value Plot Species Value
2121321222629303r323334C. 1'aPonica
C. iaPoilic/aC juPonic'a
C. iaponicaC. J'aPonica
C. J'aPonica
C. 1'aPonica
C. jaPoJ7ic'a
C 1'aPonica
C j'aPotzica
C. iciponicaC y'aPtJnica
-1.92-1.61-2.74-1.04-l.97-1.33-1.62-2,88-1.43-1,68-L61-1.611345678101114151617181920232,l2irt272835C, obttfsaC.
obtttsaC.
obtusaC.
obtusaC
obtusaC
obtusaC
obtttsaC
obtttsa
C obtusa
C. obtttsa
C. obtzfs'a
C. obtusa
C obtusa
C obtusa
C obtusa
C obtttsa
C obtusa
C. obtttsa
C obtusa
C. obtt{sa
C. obtusa
C. obtusa
e.83
3.25
O,Ol
2.46
2.05
1.44
O.27
O.76
2,N
2.37-O,88
e,o7
2.12
l.(}5
O.40
O.12
2.57
O.97
O,97
O.39
1.62
3,40
'1'able 7Testfromfer equality betweEn preportions
object-oriented classification in aef
area by species obtained
cornpartment
fl'Olllforestragisteralld those obtained
Compartment Pearsonchi-squure df Asyniptoticsignificance level
219220221225227229 2,628O.9460668O.9IOL5112.285222222 O.269O.623O.716O.634O,・170O.319
f R)x Pkinn.16.・2Z?284 eOIJ)
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282 Hi'mtaet at
se-ge'
60itgEecoli=
4ee-g8'
2o
e
kx
+ltercslitcistcr
--Obieet-O:foTlteticlassificution
"・ /--'
80
8 6ons9cug.c
40.=o"g8'
2o
C/,jcpnnica C.ohtusa Aroad-teavud
n]ixedfb"esl
Species
Compartment 2 l 9
o
+FeresLreghlcr
-e-Object-ovicnteclthassifeation
-x- --
--..x
C',./'aponica Cohrttsa Broadleave[ff
nittrEtiJb"'c'st
Species
Compartment220
80
8 6olg,L・o[
40g'tg8'
2o
oC.iaptmiea Cobtu,sa Bt'itad-teavevttt
nlirelfY})resr
Species
Compartment221
80
ge 6ets9ru5.
40.=o-g8'
2o
e
u.x
-tvFerestregtter・deObjcct-oiientedclassilicaLion
.-7
C i[vmniea C/. obtusu tlreadleai'edi
n/ixedjb)'est
Speoie$
Compartment 225
80
ge 60A9re6
40,sg8'
2o
o
-.-
+Forcstrcghter
+Obj'ccr-orbmcdcinssificatlan
st--/
ee
8 6oG9tu-oc
4e9'toQ9za
2e
C,jcmponica C,t)btusa Bs'oad-ieaveti,
rnixedforest
Species
Compartment227
o
m+"l"ovestregkstei"-'Obiecl-orientedclassificathm
x
(',J'"ponica {tohtu,xtt :/'outd-Iea/,ed'
inixed.forc,vt
Species
Compartment 229
Fig.7TheforcstInelltresults from
res.ister andthc
comparison
those obtainedbetureen
proportions of area
frorn image seglnentation ofby
species
QuickBirdobtaineddata in a1'roin
theconlpart-
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Saginentation a}ttt Cinss4'ti('atiwt tm'tk Discn'niitmnt Amal.x'sis of Otficmeini ,vafJlispe'cimtand 1'anchromalic Data to Di3'ting,ttisk CoPtotneiin .iaPoizica aiid Chantaec.iPan's obliLya thtches 283
of 21 years to 6e years of age, and this distribution almost
corresponds to the stand age distribution of Japanese artificial
forests (FoREsTRy AGENcy ok' JApAN, 2oo5). Further investiga-tion is required to distinguish between Cl'aPonica and C obtu-
sa stands of mo years and under of age, where canopy dose notclose enoug'h, or those of oo years ot age and over, where sorne
broad-leaved trees invade,
Test for Equality
The results from the comparison between proportions ef
area by species obtained from the forest register and those
obtained from image segmentalion and classification of
QuickBird data in a compartnient are shown in Fig. 7. It is
clear that the proportion of area by species obtained from the'forest
register and that obtained from image segrnentation and
classification in a compatment are very similar. The results of
the test for equality between their proportions are shewn in
Table 7. The proportien of forest type in each compambnent
obtained from forest register and that obtained freni ima.ue
seginentation and classification show good agreement, indica-
ting the nffectiveness of object-oriented classiiication in practi-
cal use. It is expected that rcusonable forest type tnapping byobject-eriented classification for high-resolution satcllite data
can be applied to suitable forest managemenL
CONCLUSIONS
In this study, we investigated the relationship between pa-rameters {n image segnientation applied to high-resolution sat-
ellite data and generated object size, and we distinguished ob-
jects of C J'mponica and C obtusa by ineans ol discrimillantanalysis. The findings are summarized below;
1. It is considered that seginentation using sc to 1oo lor the scale parameter, with which a stand ol the sanie forest type
was divided into three to five olziects, is practically applica-
ble to forest type mapping using QuickBird data.2. Broad-leavedfmixed forests and plantations could be cor-
rectly distinguished using the NDVI threshold when we used
high-reso]ution satellite data obtained during the leafless season.
3. Ptttches of C]'aponica and C obtusa could be distinguished
with the linear discTiminant function using' the average and
standard deviation of QuickBird panchromatic data, four
bands of multispectral data and NDVI as independent valti-
ables, The percentage of correct results for C1'aponica dis-
crimination was 100% and that for C obtttsa discriminEttion
was 95.5%.4. As a result of the test for equality between proponions o[
area by species obtained from the forest registei' and those
obtained from image seginentation of QuickBird data in a
cornpartment, the propertions were in good agreement, indi-
cating the effectiveness of object-oriented classification for
f R)n Pimtn. 1a2Z?i284 (2011)
practical use.
Object-oriented classification for satellite data is increas-ingly used in forest type mapping and further progress isexpected in detennining purameters and eN,aluating the classi-
fication results. High-resolution satellite data is also being ap-
plied Ior estimating stand a"ributes such as stand density andstand volume in C,1'aiponica and Cobtttsa plantations (HiRATA,2008; HiRATA et al., 2oo9), and the integrated use of spatial
inforniation obtained from objecVoriented dassilicatien and
stand attributes estimated from panchromatic clata analysis wil]
be required.
ACKNOWLEDGEMENTS
This study was funded by the project entitled "Develop-
ment of Eco-lriendly Management Method for Water and Agro-Forested-Aqua-Ecosystems in Watershed and Estuary Areas" of
the Ministry of Agriculture, Forestiy and Fisheries.
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