Hi-Tech Authentication for Palette Images Using Digital Signature and Data Hiding

Transcription

1 The Iteratoal Arab Joural of Iformato Tehology, Vol. 8, No., Aprl 0 7 H-Teh Authetato for Palette Images Usg Dgtal Sgature ad Data Hdg Aroka Jasra, Regasvaguruatha Rajesh, Ramasamy Balasubramaa, ad Perumal Eswara Departmet of Computer See ad Egeerg, Maomaam Sudaraar Uversty, Ida Abstrat: A sheme that tegrates dgtal sgature ad data hdg to provde h teh authetato for palette mages s proposed ths paper. The sheme extrats dgtal sgature from the orgal palette mage ad embeds t bak to the same palette mage, avodg addtoal sgature fle. Dgtal sgature geerato s employed usg ellpt urve based publ key ryptosystem. The performae of ellpt urve based publ key ryptosystems s maly appoted by the effey of the uderlyg fte feld arthmet. Istead of dretly sedg a orgal palette mage to repets, oly the embedded opy s set assoated wth sged dgtal sgature. Expermetal results show that seurty s aheved wthout sarfg the mage qualty. Keywords: Dgtal sgature, ellpt urve ryptography, karatsuba multplato, data hdg, palette mage, ad olor mappg futo. Reeved Jue 7, 008; aepted May 7, 009. Itroduto I a deade ago, multmeda doumets are rarely avalable to the mass osumer market. However, as the rapd developmet of the pervasve dgtal formato tehology, everyoe s omputer a have hgh qualty mage ompresso, reasg etwork badwdth ad aessblty, dese portable storage meda, ad ompoudg proessg power. Nevertheless, these tehologal advaes lead to aother rss. Multmeda users had the ablty to tamper wth, produe opes of, ad llegally redstrbute dgtal otets. Wthout solvg ths seurty ssue, dgtal multmeda produts ad serves aot take off a e ommere settg. To solve ths problem, a omprehesve approah for palette mage authetato usg dgtal sgature ad data hdg tehque s trodued here. Palette mages are popular multmeda ad teret applatos. Eah palette mage s omposed of a olor palette ad a set of olor dexes. The olor palette s a lst of etres of represetatve olors the mage, ad the olor dexes are some poters to those palette etres that spefy the redgree-blue RGB) olors the mage. Use of ths type of palette mage format has the effet of mage ompresso, whh helps savg storage spae ad redug trasmsso tme. A example of palette mage s that of the Graphs Iterhage Format GIF) [6]. Dgtal sgature ad ryptography [0] are urretly two stadardzed approahes to protet dgtal otets. Dgtal sgature [4] s a eletro sgature that s used to authetate the detty of the seder of the palette mage ad to esure that the orgal doumet of the palette mage that has bee set s uhaged. Frst the mage seder extrats some formato depedet o the otet of the orgal palette mage ad erypts t to a small sze fle, whh s alled sgature. The the sgature fle s set to the repets alog wth the orgal palette mage. The repets use the same algorthm to extrat the otet-depedet formato of the reeved palette mage. If the repets extrated formato mathes wth the sgature, the owershp ad the tegrty of the reeved palette mage are authetated. A obvous drawbak of ovetoal dgtal sgature shemes s the extra badwdth eeded for trasmsso of the sgature. To overome ths drawbak, the ombed dgtal sgature [4] ad dgtal data hdg [] sheme s proposed for palette mage authetato. The bas dea of the ombato s as follows: The mage provder extrats the otet depedet sgature from the orgal palette mage, ad the embeds t bak to the same mage as a hdde data. These palette mages a oeal seret data wthout arousg suspo whe the resultg stego-mages are speted or trasmtted over the Iteret. The reever extrats the sgature ad the hdde data from the reeved mage at the same tme. If the sgature ad the hdde data math, the reeved palette mage s thought to be authet. Chh-Husa [5] proposed robust data hdg tehque palette mages. Ths dea s exteded to dgtal sgature applatos here, formg the otet-based dgtal

2 8 The Iteratoal Arab Joural of Iformato Tehology, Vol. 8, No., Aprl 0 sgature embeddg ad extrato sheme, whh s robust agast ovetoal ompresso algorthms. I ths paper, a effet Ellpt Curve Cryptography ECC) tehque usg a ew Galos feld proessor the mplemetato of ellpt urve groups s used to geerate the dgtal sgature for palette mages ad data hdg tehque usg bary valued olor- mappg futo to embed the geerated dgtal sgature oto the same palette mage. The remader of ths paper s orgazed as follows: seto, a bref desrpto of the dgtal sgature sheme s gve. I the ext seto a overvew of the data hdg tehque s gve. I Seto 4 the proposed arhteture s preseted. Expermetal results are desrbed seto 5. Coluso ad future work s gve seto 6.. Dgtal Sgature Dgtal sgatures are aalogous to the had wrtte sgatures. Dgtal sgatures ad had wrtte sgatures are based o the fat that t s very hard to fd two people wth the same sgature. A major dfferee betwee hadwrtte ad dgtal sgatures s that a dgtal sgature aot be a ostat; People use publ key ryptography to ompute dgtal sgatures by assoatg somethg uque wth eah perso. Whe publ key ryptography s used to ompute dgtal sgatures, the seder erypts the mage wth hs ow prvate key. Ths sgature a later prove the owershp, detfy a msappropratg perso, trae the marked doumet s dssemato through the etwork, or smply form users about the rghts holder or the permtted use of the data. A Dgtal Sgature Algorthm DSA) was spefed a U.S. Govermet Federal Iformato Proessg Stadard FIPS) alled the dgtal sgature stadard DSS). Its seurty [] s based o the omputatoal tratablty of the Dsrete Logarthm Problem DLP) prme order sub groups of Z P *. The Ellpt Curve Dgtal Sgature Algorthm ECDSA) s the ellpt urve aalogue of the DSA. ECDSA was frst proposed 99 by Sott Vastoe respose to Natoal Isttute of Stadards ad Tehology NIST) request for publ ommets o ther frst proposal for DSS. It was aepted 998 as a ISO Iteratoal Stadards Orgazato) stadard ISO 4888-), 999 as a ANSI Amera Natoal Stadards Isttute) stadard ANSI X9.6), 000 as a IEEE Isttute of Eletral ad Eletros Egeers) stadard IEEE 6-000) ad a FIPS stadard FIPS 86-). It s also uder osderato for luso some other ISO stadards. Fgure shows that Ellpt urves are ot ellpses. They are amed so, beause they are desrbed by ub equatos smlar to those used for alulatg the rumferee of a ellpse. A ellpt urve [, ], may be defed as a set of pots o the oordate plaes, satsfyg the equato of the form y [ + xy] = x + ax + b ) The square braket meas that the term s optoal. x ad y are varables, a ad b are ostats. However these quattes are ot eessarly real umbers; stead they may be values from ay feld.e., x, y, a & b are hose from a fte set of dstt values... Ellpt Curves over Galos Feld Ths seto defes a group ostruted from pots o ellpt urves over Galos Feld m ) [7, ] ad the effet mplemetato of operatos ths group. A o sgular ellpt urve E over GF m ), E GF m )) s the set of solutos to the followg equato wth o ordates the algebra losure of E. y + xy= x + ax + b ) where a, b are GF m ), ad b s o-zero. Suh a ellpt urve s a abelo group. The umber of pots ths group s deoted by # E GF m )).The rual property of a ellpt urve [9] s that, the resultat pot obtaed by addg two pots o the urve s also o the urve. The addto rule satsfes the ormal propertes of addto. If P = x, y ) ad Q = x, y ) are pots o the ellpt urve the addto rule has the form where x, y ) + x, y ) = x, ) ) y x = L + L+ x = x + a 4) y = + x + y 5) L x + x ) L = y + y ) / x + ) 6) x & a s GF m ) If x = x ad y = y the x = L + L+ a 7) x = L ) * y = + x 9) L = x + y / ) 0) x Aga there are some speal ases whh must be osdered: f x = x ad y = x + y the the result s zero, ad f ether pot s zero, whereas f P ad Q are ot equal t s alled pot addto. Multplato s defed by repeated addto.e., Q = kp= P+ P+ P+... k tmes ) Ths a be omputed usg pot addto ad pot doublg. I partular for a ellpt urve E, t reles o the fat that t s easy to ompute for k GF m ) ad P, Q E. Q= kp )

3 H-Teh Authetato for Palette Images Usg Dgtal Sgature ad Data Hdg 9 Fgure. Ellpt urve. The dffulty of the problem depeds o the group, ad at preset, the problem ellpt urve groups s orders of magtude harder tha the same problem a multplatve group of a fte feld. Ths feature s a ma stregth of ellpt urve ryptosystems. To perform multplato[, 8] of large umbers may) fewer operatos tha the usual brute fore tehque of log multplato GF m ) karatsuba Karatsuba ad Ofma 96), multplato of two - dgt umbers a be doe wth a bt omplexty of less tha usg dettes of the form a + b.0 + d.0 ) s equal to a + [ a+ b) + d) a bd]0 + bd.0 ) Proeedg reursvely the gves bt omplexty O log ), where log =.58 < Borwe et al. 989). The best kow boud s Olog) steps for >> Shohage ad Strasse 97, Kuth 98). The steps volved Ellpt Curve Dgtal Sgature Algorthm ECDSA) are key par geerato, sgature geerato ad sgature verfato. For sgature geerato ad verfato, the well kow Hash algorthm s used. For key par geerato Karatsuba multplato ad pot addto are employed. I key par geerato, the radom or pseudoradom teger K S s seleted to be our feld GF m ). P s a pot o the ellpt urve, kow as the geeratg pot ad s obtaed by multplyg two other pots o the ellpt urve by karatsuba multplato. The publ key K P )s obtaed by salar multplato pot addto) of K S ad P whh s aga a pot that les o the ellpt urve. The prvate key s kept as seret whereas the publ key s kow to the seder ad reever. The reever who kows about the seder's publ key a authetate the sgature usg hs prvate key. Ths esures that ayoe wth aess to the publ key of the sger may verfy the sgature. P -,j-) P,j-) P +,j-) P 4 -,j) X, j) Fgure. A Pxel X ad ts four preedet eghbours P).. Color-Orderg Relatoshp ad Color Mappg Futo for Data Hdg The dea of data hdg s to embed the seret formato dgtal sgature) by modfyg the gve palette mage [5] wthout reatg oteable artfats. The repet a orretly extrat the embedded formato from the stego mage, whle the other people are uaware of the exstee of the seret behd the stego mage. Ths s a ew data hdg tehque whh embeds data by modfyg the gve mage attrbutes lke ts olors palette mages lke GIF).Ths tehque s based o the use of a ew type of olor-orderg relatoshp, from whh a olor mappg futo s defed wth bary values as output. Frst, mage pxels are lassfed as data embeddable or oembeddable, ad oly the former oes are used to embed seret data. Whe a seret data bt s to be embedded, the data embeddable pxel s olor s adjusted based o the olor mappg futo output so that the seret formato hdde the stego mage s vsually ad statstally udetetable by the truder. Ths tehque provdes a good balae betwee stegomage qualty ad data-embeddg apaty. Ths adaptve method a be employed to oeal a moderate amout of data ad has the least modfato of pxel values. Gve a pxel X the palette mage, ts preedet eghbors are those four eghbourg pxels, amog the eght eghbourg oes a eghbourhood as show fgure. The olor orderg relatoshp s defed as follows: v > v) or v = v adr > r) or v = v adr = r adg= g) r = r adg = g adb = b ) >, f R o = ) = f <, otherwse where ad be two olors wth RGB values r, g, b ) ad r, g, b ) respetvely. The lumae value V ad V of ad s alulated as V = 0. r V = 0. r g g + 0. b + 0. b 4) Gve a pxel X the palette mage, ts preedet eghbours are defed to be those four eghbourg pxels, amog the eght eghbourg oes a eghbourhood of, whh are vsted sequee before the other four durg the le by le raster sag. More spefally, f t s loated at oordates, j) the put mage, the ts preedet eghbors are the four pxels loated at -, j),, j-), +, j-) ad -, j-). It s show Fgure. The olor mappg futo f e m s defed as:

4 0 The Iteratoal Arab Joural of Iformato Tehology, Vol. 8, No., Aprl 0 f em 0, f >, f > > = 0, f > >, f > > 0, otherwse 4 5) where ¹ through 4 ¹ are the result of sortg the values of to 4 aordg to the olor orderg relatoshp wth ¹ beg the largest. It a be see that the futo depeds o the orderg of the olor of X amog those of the four preedet eghbors of X. I addto, to redug possble qualty degradato the resultg stego mage, the pxels the over mage are lassfed to data embeddable ad oembeddable oes durg the raster sag proess. Oly data embeddable pxels are used for dgtal sgature hdg; oembeddable oes are skpped. Let be the orgal olor of a gve pxel X ad ¹ a possble replaemet for the olor palette. Whe the olor of X s, assume that the orrespodg output of the olormappg futo of X s b, ad that the orrespodg maxmum olor dfferee betwee X ad ts four preedet eghbors s β. Whe the olor of X s replaed by ¹, assume that the orrespodg values of b ad β are haged to be b¹ ad β¹ respetvely. Also assume that the umber of dstt olors of X s four preedet eghbours s α. A pxel s defed to be data embeddable f the followg three odtos are satsfed:. α s larger tha a threshold value T d.. β s smaller tha a threshold value T.. There exsts a olor ¹ wth the orrespodg b¹ beg the verse of b, ad the orrespodg β¹ beg smaller tha the threshold value T d. Or equvaletly, the data embeddablty of a pxel s defed as follows: X s data embeddable, f α>t, β<t d, ad there exsts a ¹ suh that b¹ b ad β¹ <T d. 4. Proposed Work The proposed authetato sheme s a kd of seder reever protool. The seder geerates the sgature ad serts t bak to the orgal palette mage as a hdde data. I the reever s sde, the owershp ad tegrty s verfed by omparg the sgature ad embedded data both extrated from the reeved palette mage. The proedures both seder ad reever sdes are desrbed detal below. 4.. Dgtal Sgature Geerato I sgature geerato, a geerator pot G s a salar multpled wth a ostat k the feld of GF m ) resultg a pot P) o the ellpt urve. The publ key K P ) s omputed usg K P = K P 6) S where, K S s the seret key whh s atually a radom umber from [: -]; s the umber of pxels the palette mage I P. Seret Key K S Fgure. Dgtal sgature geerato. The dgtal sgature D S ) s omputed as follows: D Palette Image I P SHA- DSA sgature geerato { SHA I ) K. K }mod) S q P + Image Dgest = 7) where, SHA s the 60 bt hash futo, K q = x mod), x s the x oordate of the pot P. Fgure shows the geerato of dgtal sgatures. Ths proess uses the hash futo of the palette mage thereby resultg the mage dgest. Hashg may be defed as the trasformato of a strg to a usually shorter ad fxed legth value or a key that represets the put palette mage I P ). Durg sgature geerato, the trasmtter s seret key K S ) s used alog wth the mage dgests to geerate a bt stream D S ). I ths applato, these bts are osdered otet depedet dgtal sgature ad wll be embedded bak to orgal palette mage as a hdde data. Thus the sgature for the mage I p s D S, K q ). 4.. Dgtal Sgature Embeddg Proess The dgtal sgature to be embedded s represeted as a bt stream, deoted as D S = d d.d. The bas dea of the data-embeddg proess s to hek eah pxel of the orgal palette mage I P ) a raster sag maer for ts data embeddablty, ad to embed eah seret bt d of D S sequetally to every data-embeddable pxel utl the bt stream of D S s exhausted. Durg eah seret bt dgtal sgature bt) embeddg step, f the bary output of the olor mappg futo f em s the same as the seret bt value to be embedded, the olor of the urretly heked data embeddable pxel s kept uhaged; otherwse s replaed wth a olor opt, alled the optmal replaemet olor for X, ths proess s show Fgure4. For a partular olor data embeddable pxel olor) the replaemet olor R ) s the olor S q Dgtal Sgature Bt Stream D S )

5 H-Teh Authetato for Palette Images Usg Dgtal Sgature ad Data Hdg wth mmum olor dfferee, seleted from ts palette. Fgure 4. Dgtal sgature hdg wth the same palette mage. Publ Key Fgure 5. Dgtal sgature extrato ad verfato. Ths s gve by, Threshold Color Orderg & Mappg Proess Yes Palette Image I P) Bt Comparso Is Math? = m, where s the olor from palette P that satsfes the odtos: R. together wth ts eghbors as put to f em yelds bary output b 0 that s the same as the dgtal sgature bt b;. X s stll data embeddable whe ts olor s set to. If the olor dfferee Optmal Color Replaemet C r) Stego-Image I s) Embeddable Pxels No Stego-Image I s ) Sha- DSA Sgature Verfato Image Dgest s smaller tha the predefed threshold T C or f N s empty the take R as the desred optmal replaemet olor opt for X ad stop; otherwse, fd the olor amog those N, whose olor dfferee from s the mmum,.e., R Dgtal Sgature Bt Stream D S Color Orderg & Mappg Proess Compare Sgatures Extrated Embedded Data Expeted Sgature R = m ε N, the take R as opt N deotes the subset. That otas the olors of the four preedet eghbors of X. Fgure the olor dfferee betwee two olors ad s the Euldea dstae betwee the RGB values r, g, b) ad r, g, b ) of ad respetvely. where [ r r ) + g g ) + b b ) ] / = 8) The resultat stego mage otas the dgtal sgature embedded to t. 4.. Verfato At the reever, the reeved stego mage I S ) s subjet to two parallel proessg amely, the DSA sgature extrato proess ad the embedded data extrato proess DSA Sgature Extrato Proess The hash futo for the stego mage I S ) s Computed usg r = SHA I ) ad also S DS = D mod ) S s alulated. The sgature s verfed usg the followg: r = r * D mod ) 9) S r = K * D mod ) 0) q S mod ) x = r.p+ r * K p K m = x where ) The sgature s aepted f K m s equal to K q Embedded Data Extrato Proess I ths proess the data embeddable pxels are detfed from the stego mage I S ). These pxels are gve as put to the ext stage.e., the olor of eah embeddable pxel ad those of ts four preedet eghbours are gve as put to the olor orderg ad mappg futo. If the output s the the extrated seret bt s take to be otherwse, 0. The extrated dgtal sgature s ompared wth the extrated embedded data for verfato. The verfato proess s show Fgure Advatages. Ths method does ot mapulate mage palettes, resultg o abormal palette struture.. Prevets the resultg stego-mages from havg outstadg pxels whh are vsually or statstally detetable.. Se ths method does ot alter the palette, t does t lude speal patters suh as Tw peaks).

6 The Iteratoal Arab Joural of Iformato Tehology, Vol. 8, No., Aprl 0 4. Ths tehque provdes a good balae betwee stego mage qualty ad data-embeddg apaty. 5. Stego mage s vsually ad statstally udetetable by the truder. 5. Expermetal Results Ths paper demostrates the feasblty of ostrutg very fast ad very seure publ key systems wth the use of karatsuba log for multplato. Some expermets are desged to prove the effey of the proposed sheme. Frst, the palette mage qualty after dgtal sgature serto s vestgated. Seodly, the maxmum umber of bts that a be embedded to the gve palette mage s alulated. The 47 7 Grl. GIF mage s used for expermets. The Peak Sgal to Nose Rato PSNR) s omputed to evaluate the embedded mage qualty. PSNR s gve by, PSNR = 0 log 0 55 / σ ) where σ s the mea square of the dfferee betwee the orgal palette mage ad the embedded oe. Fgure 6 shows the Grl mages before ad after dgtal sgature serto. No obvous degradato s observed Fgure 6 b) who s PSNR s 5.6. a) Orgal grl mage. b) Grl mage after embeddg dgtal sgature. Fgure x 7 Grl.GIF mage. Table. Maxmum umber of embeddable pxels ad quattatve. Measuremet for Varous Images. Image Total embeddable pxels T =,T d=0 T =,T d=0 PSNR Grl 47 7) Fsh 0 9) Veus 56 56) Chrome_ 0 0) Veus 5 56) From Table, t s observed that the umber of bts that a be embedded s reased, whe T s dereased ad T d s reased. Also t s lear that ths method provdes good trade-off betwee embeddg apaty ad mage qualty, ad so s qute flexble. Whe palette mages ota lmted olors that are vsually uorrelated, the proposed method a yeld embeddg results wth better vsual qualty. From the PSNR values, t s observed that ths tehque does t trodue ay vsual artfats ad the sgature a be extrated orretly. 6. Colusos ad Future Work Dgtal sgature ad data hdg are two tehques used for opyrght proteto ad authetato, respetvely. I ths paper, a ombed sgature ad watermark sheme s proposed for mage authetato. Covetoal dgtal sgature shemes usually eode the sgature a fle separate from the orgal mage, thus requre extra badwdth to trasmt t. The proposed sheme extrats sgature from the orgal mage ad embeds them bak to the mage as hdde data, avodg addtoal sgature fle. Furthermore, the sheme ot oly a verfy the authetty ad the tegrty of mages, but also a loate the llegal modfatos. Expermets show that our sheme s robust to reasoable ompresso rate whle preservg good mage qualty, ad apable to authetato. Future work wll be foused o more robust sgature extrato method ad possble ways to reover the llegally modfed stego mage. Se ths adaptve tehque does ot mapulate mage palettes, the truder aot arouse suspo for abormal palette struture ad speal patters lke tw peaks). It also prevets outstadg pxels. Ths tehque provdes good embeddg apablty keepg the stego mage qualty. But the T ad T d values should be take to aout aordg to the legth of dgtal sgature. Referees [] Agew G., Mull R., Oyszhuk I., ad Vastoe S., A Implemetato for a Fast Publ-Key Crypto Systems, Computer Joural of Cryptology, vol., o., pp. 6-79, 99. [] Agew G., Mull R., ad Vastoe S., A Implemetato of Ellpt Curve Cryptosystems over F 55, Computer Joural of IEEE o Seleted Areas Commuato, vol., o. 5, pp , 99. [] Cetrom Researh, The Ellpt Curve Cryptosystem, Certom, /dex.php/e, Last Vsted 008. [4] Elgamal T., A Publ Key Crypto Systems ad a Sgature Sheme Based o Dsrete Logarthms, Computer Joural of IEEE

7 H-Teh Authetato for Palette Images Usg Dgtal Sgature ad Data Hdg Trasatos o Iformato Theory, vol., o. 4, pp , 985. [5] Frdrh J. ad Du R., Seure Stegograph Methods For Palette Images, Proeedgs of rd Iteratoal Workshop o Iformato Hdg, Germay, pp.47-60,999. [6] GIF Color Map Stegography, www. darksde.om.au/gfshuffle, Last Vsted 008. [7] Hakerso D., Heradez J., ad Meezes J., Software Implemetato of Ellpt Curve Cryptography over Bary Felds, Proeedgs of Workshop o Cryptograph Hardware ad Embedded Systems, pp. -4, 000. [8] Karu P, Pratal Comparso of Fast Publ-Key Cryptosystems, rypto/fast_pk_rypto.pdf, Last Vsted 008. [9] Kobltz N., Ellpt Curve Cryptosystems, Proeedgs of Mathamats of Computato, pp. 0-09, 987. [0] Meezes J., Oorshot C., Vastoe S., Hadbook of Appled Cryptography, CRC press, 997. [] Mller V., Use of Ellpt Curve Cryptography, Proeedgs of CRYPTO 85, Sprger Verlag Leture Notes Computer See, pp , 986. [] Pettoals F., Aderso R., ad Kuh M., Iformato Hdg: A Survey, Proeedgs of the IEEE Speal Issue o Proteto of Multmeda Cotet, pp , 999. [] Potheval D. ad Ster J., Seurty Proofs for Sgatures, Proeedgs of Eurorypt, pp. 59-6, 996. [4] Rvest R., Shamr A., ad Adlema L., A Method for Obtag Dgtal Sgatures ad Publ-Key Cryptosystems, Computer Joural of Commuatos of the ACM, vol., o. 5, pp. 0-6, 978. [5] Tzeg C., Yag Z., ad Tsa W., Adaptve Data Hdg Palette Images by Color Orderg ad Mappg wth Seurty Proteto, Computer Joural of IEEE Tras. o Commuato, vol. 5, o. 5, pp , 004. Aroka Jasra reeved the BS ad MS degrees eletros ad ommuato egeerg 996, ad 00, respetvely, from Maomaam Sudaraar Uversty, Ida. I 997, she joed the Departmet of Eletros ad Commuato Egeerg, Karuya Isttute of Tehology, Taml Nadu ad worked for a perod of two years. I Deember 00, she joed Maomaam Sudaraar Uversty, Taml Nadu, where she s urretly workg as assstat professor the Departmet of Computer See ad Egeerg. Her researh terests lude dgtal Image Proessg, Neural etworks, data mg, mage seurty, wavelets, ad vetor quatzato. Regasvaguruatha Rajesh reeved hs BS ad MSC degrees eletros ad ommuato egeerg from Madura Kamaraj Uversty, Ida the year 988 ad 989, respetvely. He ompleted hs PhD omputer see ad egeerg from Maomaam Sudaraar Uversty the year 004. I September 99, he joed Maomaam Sudaraar Uversty where he s urretly workg as assoate professor the Computer See ad Egeerg Departmet. Hs researh terests lude dgtal mage proessg, wreless etworks, pervasve omputg, ad parallel omputg. Ramasamy Balasubramaa reeved the BS degree omputer see ad egeerg, from Bharathdasa Uversty, Truh, Ida ad MS omputer see & egeerg, from Regoal Egeerg College, Truh. Cretlly, he s dog PhD degree at Maomaam Sudaraar Uversty, Ida. Se 994, he s workg as assoate professor the Departmet of Computer See ad Egeerg, Maomaam Sudaraar Uversty. He has authored oe omputer etworks book, more tha 0 oferee papers. Hs researh terests lude mage segmetato, mage ompresso, otet-based mage retreval, ad Data Mg. Perumal Eswara reeved the MS degree omputer see ad formato tehology from Madura Kamaraj Uversty, Ida 00, ad the MS degree omputer ad formato tehology from Maomaam Sudaraar Uversty, Ida 005. He s urretly pursug the PhD the Departmet of Computer See ad Egeerg of Maomaam Sudaraar Uversty. Hs researh terests lude dgtal mage proessg, fousg o olor mage edge deteto, data mg, ad omputer vso.