Journal of Engineering Science and Technology Review 7 (1) (2014) Research of Anti-Noise Image Salient Region Extraction Method

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1 Jest Jounal of Engneeng Scence and echnology Revew 7 () (04) JOURNAL OF Engneeng Scence and echnology Revew Reseach of Ant-Nose Image Salent Regon Extacton Method Bng XU,*, Shy XIE and Zhende LI Dept. of nfomaton college, Guangdong Ocean Unvesty, Zhanjang cty 54088, Guangdong povnce - Chna Dept. of softwae college, Guangdong Ocean Unvesty, Zhanjang cty 54088, Guangdong povnce Chna Receved 5 June 03; Accepted 3 Januay 04 Abstact he exstng mage salent egon extacton technology s mostly sutable fo pocessng nose-fee mages, and thee s a lack of studes on the mpact of nose on mages. In ths study the adaptve kenel functon was employed n mage salent egon detecton. he salent popety of a egon was detemned by the dssmlates between the pxels of the mage egon and ts suoundngs. he dssmlaty was measued as a deceasng functon assocated wth adaptve kenel egesson. he poposed algothm used mult-scale fuson method to obtan the salent egon of the whole mage. As adaptve kenel functon has stong ant-nose chaactestcs, the poposed algothm was chaactezed wth the same obustness. A numecal smulaton expement was conducted on salent egon extacton of mages wth nose and wthout nose. A compason between ths study s esults and two exstng salent egon extacton methods evealed that the poposed method n ths study was supeo n ts extacton accuacy of mage salent egons and could educe ntefeence of mage nose. Keywods: Image Salent Regons, Adaptve Kenel Functon, Image Nose, Image Extacton. Intoducton Vsually salent egons ndcate the pats of the mage that ae of nteest to human eyes [], []. As salent egons of an mage epesent the man content of the mage, accuately extactng the salent egons plays an mpotant ole n mage ecognton and mage eteval [3], [4]. Meanwhle, salent egons ae also ctcal n compute vsual tasks, as accuate extacton of salent egons allows lmted esouces to be used n pocessng egons o object of nteest. In ecent yeas, moe and moe studes focus on how to detect salent egons of nteest n natual mages. A lage numbe of salent egon extacton algosms have been poposed [5], [6], [7], [8], whch convet the mage to gay scale mage contanng salent egons, and epesent salent egons n the mage wth bght gay values. hese algothms obtan good esults n pocessng shap and hgh fdelty mages. Howeve, n pactcal applcatons, the captued mages usually contan nose, especally mages captued wth nfaed magng systems. hese mages have low SNR (Sgnal Nose Rato) and the mage nose s patculaly seous. he pesence of nose makes mage salent egon extacton dffcult. Howeve, not many exstng studes focus on ths ssue. akeda and othe eseaches have poposed an adaptve kenel functon [9], whch has been wdely used n mage nose emoval, face ecognton and object detecton [0], [], []. Based on pevous studes, ths pape poposes a salent egon extacton method wth adaptve functon as the key technology. As adaptve kenel functon has obustness n dealng wth mage nose, the poposed salent egon extacton algothm has the same obustness and could * E-mal addess: bngxuswcd@63.com ISSN: Kavala Insttute of echnology. All ghts eseved. educe the jammng of mage nose and mpoved accuacy n salent egon extacton. In ode to vefy the effectveness of ths method, an analyss was made of the salent egon extacton capacty of the algothm n pocessng mages wth and wthout nose by employng the numecal smulaton pogam. In addton, a compason was made of ths algosm wth the two methods poposed n lteatue [4] and [5] egadng salent egon extacton. he esults ndcate that the poposed method n ths pape can effectvely extact the salent egons of an mage and wth hgh accuacy n cases whee the mage contans a lage amount of nose.. Image Salent Regon Extacton Judgment about salent pxel egon s based on dssmlates between ths small egon and the suoundng egon. It defnes y the value of dssmlaty between the cente pont x of the obseved mage and ts neghbong ponts. Accodng to the estmaton theoy, each value of y s a potental theshold value fo the salent egon; howeve, ths potental value can be eoneous. he model can be descy y = s + η, =, K, N () Whee s s mage salent egon value, and η s the eo tem, N s the numbe of sampled mage patches. By solvng the followng least squaes poblem wth weghts, salent egon value s obtaned at poston x of the mage. he poblem can be descbed as:

2 Bng XU, Shy XIE and Zhende LI/Jounal of Engneeng Scence and echnology Revew 7 () (04) N s (x ) = ag mn y s K y, y () whee functon. Let wth = ( ) y s the efeence value, K( y, y ) s weght y be equal to the mnmum value n a egon y as the cente, and K( y, y ) facto. Its defnton s as follows: ( ) ( yj y) h povdes the weghtng K y, y = e, j =,..., n (3) whee paamete h contols the weght of the attenuaton and the fxed value h = 0. s used hee. Mnmzaton of the fomula leads to the weghted aveage of dffeence, whee K y, y. he obtaned esult of the weghtng facto s ( ) mnmzaton s: s (x ) = n n K ( y, y ) y n = w j y (4) K ( y, y ) Let ρ be defned as the smlaty, ndcatng the degee of smlaty between the value of the mage pont x and those of neghbong ponts. Let y be defned as a monotonc deceasng functon on paamete ρ as follows: ρ y = e, =, K, N (5) Whee N s the numbe of sampled mage patches. he value of paamete ρ can be obtaned though many ways, and n ths study, adaptve kenel functon poposed by akeda was adopted [9]. hs functon has been wdely used n aeas such as mage de-nosng, face ecognton and object detecton. It can self-adapt to the local nfomaton n an mage, and has stong stablty wth mages contanng nose. he use of ths functon n the mage salent egon extacton and makng t the coe of the algothm n ths study ensues that the poposed algothm has stong stablty n handlng mages wth nose. he defnton of ntoducng paamete ρ s as follows: ( x x) C( x x) ρ = exp{ } (6) d Whee d s the scale paamete whch contols patch sze. In ths study the value of ths paamete was set to a fxed 3. C s the covaance matx, and ts specfc epesentaton s as follows: C = γ U Λ U (7) θ θ Whee U θ s the otaton matx, Λ s the tensle matx, and they ae defned as: cos sn U = θ θ θ [ ] snθ cosθ (8) σ σ 0 Λ = [ ] (9) 0 heefoe, the covaance matx contans thee paametesγ, θ andσ. Lteatue [9] povdes a method to obtan the thee paametes based on matx sngula value decomposton, as shown below: M M z ( x ) z ( x ) = U SV M M x t x t z ( ) x x and t z ( ) x t mage egon wth locaton (0) x stand fo one step value of the x t as the cente along the x and x dectons, espectvely. he opeaton of the above equaton s the sngula value decomposton of the matx, and the second column of the othogonal matx v = [ v, v ] defnes paamete θ as follows: v θ = actan( ) () v Paamete σ s detemned by the value of the dagonal n the dagonal matx as shown n the fomula below: σ s + λʹ, ʹ 0 = λ s + λʹ And paameteγ s defned by the followng equaton: γ ss + λʹ ʹ M () / = ( ) (3) Whee M epesents the sampled numbe n mage aea and the paamete n the fomula s set as a fxed value based on lteatue [9]: λʹ =, λʹ ʹ = 0.0. In extactng salent egons n lage-scale mages, salent egons ae obvously concentated on the edges of the object, esultng n loss of ntegty n salent objects. o ovecome ths weakness, mult-scale pocessng was used. Sub-samplng on dffeent scales was appled to the mages, followed by the above mentoned pocess. Intepolaton pocessng was then undetaken to mages wth salent egons extacted, so that the esulted sze of the pocessed mage was dentcal to the ognal mage. Lastly, the aveage of the obtaned mages wth salent egons was woked out wth the expesson below: 44

3 Bng XU, Shy XIE and Zhende LI/Jounal of Engneeng Scence and echnology Revew 7 () (04) M! s (x ) = s (x M! ) m (4) m= Whee m epesents the numbe of sub-sampled mages. Fg. s a eal-lfe example of mage pocessng whee salent egons of dffeent sub-sampled maged ae povded. It can be seen that f the whole mage undegoes dect pocessng, mage salent egons only appea on the edges of the object. hs poblem s well solved usng multscale pocessng of the mage salent egons. heefoe, n the follow-up numecal smulaton expement, ths method was adopted n extactng mage salent egons. Fg. Image Salent Regons on Dffeent Image Scales: (A) ognal mage, (B) salent egon of the ognal mage, (C) mage salent egon afte 60% samplng, (D) mage salent egon afte 40% samplng, (E) mult- scale fused mage (the two whte egons ae salent egons of the mage) Fg. Nose- fee Image Salent Regon Extacton, (Left) Ognal mage, (Rght) Salent egon of the mage obtaned usng the poposed algothm Above all, the basc pocess of the mage salent egon extacton s descbed below: Step : Read the ognal mage, Step : Sub-samplng the ognal mage, Step 3: Save the ognal mage and the sub-sampled mage, the total numbe s M, Step 4: Calculate paamete ρ fom the m th mage, Step 5: Get the paamete y and the weghtng facto k, Step 6: Get the salent value of m th mage, then get ) consstent salent value sx ( ) m wth the ognal mage afte samplng, Step 7: If m<m, pefom Step 4, Othewse, to the end, Step 8: Pefom the fomula (4), get the fnal salent value. 3. Numecal Smulaton Expement hs secton wll pesent the esults fom pocessng mages wth o wthout nose. Fstly, the nose- fee mage salent egon extacton esults n vaous contexts wll be povded. Fg. shows the ognal mage and the mage salent egons obtaned by applyng the poposed algothm. he esult ndcates that although both the context and the nfomaton n the mage changed, the poposed algothm was stll able to extact the salent egon of the mage. Next, the pefomance of the algothm on mages contanng nose would be studed wth thee eal-lfe examples and the esult of mage salent egon extacton s povded. In ode to show that the algothm was obust n handlng nose mages, two othe salent egon extacton methods wee ntoduced fo compason: the algothm ntoduced by Seo H. h and Mlanfa P nlteatue [4], abbevated as SM algothm and the algothm ntoduced by Rahtu E and Kannala J n lteatue [5], abbevated as RK algothm. Image captung s nevtably ntefeed wth Gaussan nose, theefoe, the expement conducted n ths study focused on mages contanng Gaussan nose. Imnose (), the nose addng functon n the Matlab pogam, was used whee the mean value was set as zeo and the vaance changed. Images wth nose that had vaance values of 0, 0.0, 0.05, 0. and 0. undewent salent egon extacton. Fg.3 pesents the esults of salent egon extacton of an mage of a sngle athlete, whee the ows and 3 show the pocessng esults adoptng SM algothm and RK algothm, espectvely, ndcatng that wth the gadual ncease of nose, the eos n salent egon extacton usng these two algothms nceased. Row 4 s the esult of extacton usng the poposed algothm n ths study. Whle the algothm was also affected by the nose, t can be seen fom Fg.3 that despte the stong nose contaned n the mage ths method was able to extact elatvely accuate salent egons. 45

4 Bng XU, Shy XIE and Zhende LI/Jounal of Engneeng Scence and echnology Revew 7 () (04) Fg.3 Results of Salent Regon Extacton: columns(a, B, C, D, E) denote mages wth fve degees of nose and the extacton esults, whee ow ndcates mages wth dffeent degees of nose, ow ndcates the extacton esults usng RK algothm, ow 3 pesents extacton esults usng SM algothm, and ow 4showsthe extacton esults usng the poposed algothm Fg.4 pesents the esults of salent egon extacton of an mage of a oom wth a compute. he esults evealed that wth stong nose n the mage, lage eos occued wth salent egons extacted usng RK and SM algothm. In contast, the salent egons extacted by the poposed algothm mantaned the accuacy. Fg.5 Results of Salent Regon Extacton: columns (A, B, C, D, E) denote mages wth fve degees of nose and the extacton esults, whee ow ndcates mages wth dffeent degees of nose, ow ndcates the extacton esults usng RK algothm, ow 3 pesents extacton esults usng SM algothm, and ow 4 shows the extacton esults usng the poposed algothm Lastly, the esults of pocessng an mage wth a moe complex buldng scene wee pesented n Fg.6. he esults evealed that despte the complex scene and stong nose contaned n the mage the poposed algothm was also able to extact accuate salent egons and keep a hgh accuacy. Fg. 4 Results of Salent Regon Extacton: columns (A, B, C, D, E) denote mages wth fve degees of nose and the extacton esults, whee ow ndcates mages wth dffeent degees of nose, ow ndcates the extacton esults usng RK algothm, ow 3 pesents extacton esults usng SM algothm, and ow 4 shows the extacton esults usng the poposed algothm Fg. 5 pesents the esults of salent egon extacton of an mage wth a complex anch scene. As RK algothm was senstve to nose, the salent woods egon was mpossble to extact when nose appeaed n the mage. SM algothm was bette n handlng nose; howeve, wth stong nose, substantal eos occued wth the extacted egon. In contast, ou algothm extacted a moe accuate salent egon. hs was patculaly the case wth mages n column E whee the salent egon extacted usng ou method was consstent wth salent egon extacted fom the nose-fee mage. Fg.6 Results of Salent Regon Extacton: columns (A, B, C, D, E) denote mages wth fve degees of nose and the extacton esults, whee ow ndcates mages wth dffeent degees of nose, ow ndcates the extacton esults usng RK algothm, ow 3 pesents extacton esults usng SM algothm, and ow 4 shows the extacton esults usng the poposed algothm 4. Conclusons In ths pape, a new algothm that s effectve n educng mage nose was poposed to addess the ssue of salent egon extacton fom mages wth nose. hs algothm extacted the salent egon of the whole mage by usng adaptve kenel functons as the key technology and employng mult-scale fuson method. Because of the obustness of adaptve kenel functons n handlng mage nose, the algothm poposed n ths study showed the same obustness when dealng wth mage nose. A smulaton expement was conducted to valdate the algothm, and the compason of ths algothm wth two exstng algothms 46

5 Bng XU, Shy XIE and Zhende LI/Jounal of Engneeng Scence and echnology Revew 7 () (04) ndcated that that the new algothm was obust aganst mage nose. Despte the obustness of the algothm poposed, the study has ts lmtatons. Futue n-depth eseach s equed to focus on mpovng the computng speed of the algothm, mult-souce nose analyss, and algothm obustness n the aea of salent egon extacton of mages contanng nose. Acknowledgements hs wok was suppoted by pogam fo scentfc eseach stat-up funds of Guangdong Ocean Unvesty (No: 353). Refeences. Buce N. D. B. and sotsos J. K., Salency, attenton, and vsual seach: An nfomaton theoetc appoach, Jounal of Vson, 9(3), 009, pp.-4. Gao D., Mahadevan V., and Vasoncelos N., On the plausblty of the dscmnant cente-suound hypothess fo vsual salency, Jounal of Vson, 8(7),008,p Itt L., Koch C., and Nebu E., A model of salency-based vsual attenton fo apd scene analyss, IEEE ansactons on Patten Analyss and Machne Intellgence, 0, 998, pp Seo H. and Mlanfa P., Statc and space-tme vsual salency detecton by self-esemblance, Jounal of Vson, 9(), 009, pp Rahtu E, Kannala J, Salo M, Hekklä J, Segmentng salent objects fom mages and Vdeos, 00 Poc. Euopean Confeence on Compute Vson, 00,pp LI Hayang, HE Dongjan, Salent egon detecton usng adaptve ccula spatal suound. Applcaton Reseach of Computes, 30(6),03,pp Zhang peng, Wang unsheng, Detectng salent egons based on locaton shft and extent tace, Jounal of Softwae, 5(6), 004, pp Wang lu, Lu xa, Ca zxng, Local salent egons based natual scene ecognton, Jounal of Image and Gaphcs, 3(8) 008, pp akeda H., Fasu S., and Mlanfa P., Kenel egesson fo mage pocessng and econstucton, IEEE ans. on Image Pocessng, 6(), 007, pp Seo H. and Mlanfa P., anng-fee, Genec object detecton usng locally adaptve egesson kenels, IEEE ans. on Patten Analyss and Machne Intellgence, 3(9), 00, pp, Hae Jong Seo, and Peyman Mlanfa, Detecton of human actons fom a sngle example, IEEE Intenatonal Confeence on Compute Vson, (),009, pp.0-7. Hae Jong Seo, and Peyman Mlanfa, Acton ecognton fom one example, IEEE ans. on Patten Analyss and Machne Intellgence, 33(5),0, pp