Data Conversion for GIS

Flat a acrlnisi~ ion for Gronraphic Inlormalion S y s t ~ m ~ is bot l~ t imp ronsumiug and expeiislrc. Most existing work is undrrtakeil usit~g manual methods which sub Cer the additional problrrn ol producing; resuIts whir11 vary arid show iuconsisre~~cy. I\ variety of automatic attd srmi-automatic melllorls liave bWll devclopcd to try lo reduce thcsc difTiculties. F'niortunatcly. many of! hesc reclmolopies fail to work w i ~ k the noisy. soiled or corruptcrl matcrial with which borrau companies typically work. '1 he ralk dcscribcs two solutions des i ~ n ~ d to Iowtr 111~ msl :u~d i t trrcsr thc rcljabiLitv of GIS data cap1 urp. T)FC;IS~I" is a product designed to rs t ra t t liriec horn p a p r d o c u ~ n c ~ ~ l s . D1I;IS'T operatcc with mmplcx or soiled rlocumcnts aud has been sl~orrbn t o si~liihcanl1y rcducc t lic cost of pmeratinp, a (.:IS, h sccond technology tackles the problem of tprsirin ge11rrario11. \1'TO-ZZ is a f~ilrp aulomatic svsI cIn fur i ltc ~enpra~ ion of terraill surfaccs from s t ~ r m i i n a ~ e pairs rapturpd from aircralt or satellites. 'Tl~e world <;IS markpt i s r u r r ~ r ~ t l y crtimated to be wort11 arounrl %.ti Ilillior~:'. Of I his. at 1~ast 7% i s dircrtty attr ib~ltablc lo data colivcrsion cos~s . Work by an indcp~ndent consult ant in Sort h .Ammica [HargZ] ha! s u ~ ~ e s t e d lliat morp than 70% of GIs dara convrrsiotl is rlo11e n~a~lual ly and ~l l a t this currently represcnls a serious hottlcneck to thr widr scalp d e v ~ i oprnent and uptake 01 (;SS[iYcl~flI]. Ovrr the lasi 1rt4 years. a rallsidtrablc rfliart has gorir into developing technology which is designed to s s i s t or aillomatt? tlre riala c o ~ ~ v r r s i a ~ i !.ask. I'11iorlunatcly. whilst most of tlkrsr drvr~lopmeuts Ilare producer] high quality drmonsf rat ions with carefully selecl rd dal a, pcrlormatlcr d r ~ r ~ d r s w l i e ~ ~ used with I hr rlocuments or i m a ~ ~ s cornmonlv used by bureau con~patiies. lIr1c11 OF llic data ronvcr~ion task takes plarr. w i f l l paper doruments which are stdnrd or 11ave bmn hand-crasetl or Land-trlited. Photographic rrrords may also be dcnradpd. .4lt houg1i a variety of computer-has~d products have llow enterrd the markct for assisting or au~oniatiug ~ h c data conversion 'Onr~lmrnt I m a ~ i n g inr CIS 'frrhnolag~ (UIGIS'I-) ip a tmdcmark of Thr 'Ii~nrr~ l r ~ s i i t l l t ~ L td 'r2111c-i! iu e trademark nf Thc ' T t ~ n n ~ I n ~ t ~ t u t r Ltd. 'SOUI~CP. D a r a t ~ r h Inr, USA task. many have yet to cwss thc commercial threshold for solrink, the bulk of scal dal a conversion. This papPr desrrib~s a new product. DIGIST. ~vh ic l~ is athe to lrack lines and contnuss on soiled or complpx documcrils and CoIlvprt the data to a GTS. \Z;. d s o sl~ow some results ~ ~ n r r a t e d by a f a ! .;rcree matching algorithm, Al'TO-%, wllirlt automaticall!. KcticratPs a n i ~ i t a l Cleva~iou Stodd (DF,\I) from slereo Imagcs. Slost Iirre I r ~ k i n g systcrlls \vr.nl.li tvit11 bi~iary (only black and white) d a ~ a in whctl t l ~ e I l~rrslloldinp; conimod!: occurs in t h p scatlncr ilsrll. r\pplying :L fisrd t hresl~old to soilrd or compl~x imagcs of d o r u m ~ n l s may rcsvlt in a s i~i~i l icant Ioss o[ image clarity. ror complex ituagrs. tllcrc i s no s i n ~ l c thrrshold valuc that can adequately he applied lo the ~ n t ire image. Thcr~forc, not hav~ng to apply a threshold at scanning time i s a disti~ict ad van tap;^. The new problem is one or workiue, will1 grey ralucd irnag~s. R ~ c ~ n t clrariges iu workstation Itartlwar~ performance now mean that there is no prul)lpn~ ill <tori tlq large data s t ~ s ill computer memory. Fbr rxan~plc . a 1:1250 Ordnar~ce Survey rnap s c a n ~ l ~ d at l5n dots per inch (dpi), rakcs up less than li rnagabytrs (lib): workstations are now rarely instdird with lrss than It? LIb of memor!.. To start I l ~ c process. the docu111rtir i s s c a ~ n r d wld loaded into the system. I:olloui~lg arl irnagv warpitig operation to arljusl I he coortlirtal c frail~r. I he uspr applirs a redt imp clippir~g oprrat ion which help$ make the lines more visiblc. Clippiug iq an operation which filtcrs out grcy rall~cs ontside a partic~rIar rarigr. Compone~its are the11 placed niatir~ally otrto the dorumcnt image and I heir ar tribute< stored. Lxarnplcs 01 components could I)? ,jt~nctior~-boxes. nianholc coyrrs. rransformcrs. pumps or whatevrr t l ~ c applicatior~ r ~ ~ a i r ~ s ' ' . 'I'htusvr points ro t IIC lirle witll I lie rnousr and 1)lC;IST then autumaticalIy tracks 1Le linc a114 connects l o I hc componcnts. Tliis nltans that ill a s i n ~ l e proccss. tlte line is automatically I racked, if '2 conl~~ctivily is ~ n a d c xpliril arid I11r user can verily the operation via tllr uscr i n t r r i a t ~ . 'Thc f i r ~ t fttUv rrp~raiionel Fyqtrrn Inr Inass data tonwrsron IR for utditv companlrs ~rrvolvrd lib I h p plrr tr i r i ly rlrpplr