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1 I H C QU C GIA HÀ N I TR NGă IăH CăCÔNGăNGH PHAN V N THU N NH N D NG CÁC BI UăM U TÀI LI U ChuyênăngƠnh:ăCôngăngh ăthôngătin Mƣăs :ă1.01.10 LU NăV NăTH CăS NG IăH NGăD NăKHOAăH C:ăăPGS.TS.ăNGÔ QU C T O HÀăN Iăậ 2007 L IăC Mă N! Lu n v n lƠ k t qu đ t đ tr ng i h c Công Ngh - c sau hai n m h c cao h c (2004-2006) t i i h c Qu c Gia HƠ N i vƠ trình nghiên c u, công tác t i Trung tơm nghiên c u vƠ phát tri n Công ngh ph n m m, ih c Công ngh , HQGHN Tr c tiên xin g i l i bi t n chơn thƠnh nh t t i PGS TS Ngô Qu c T o vƠ Th c s Nguy n Ti n S , ng i th y đƣ truy n đ t cho nh ng ki n th c đ u tiên v X lý nh vƠ nh n d ng, ng i th y đƣ dìu d t, h ng d n vƠ cho nh ng ý ki n quý báu, nh ng l i khuyên b ích su t trình tìm hi u vƠ hoƠn thƠnh lu n v n nƠy Tôi xin bƠy t lòng bi t n đ n th y cô Tr ng i h c Công ngh đƣ d y d su t hai n m h c cao h c v a qua Tôi xin g i l i c m n đ n Trung tơm nghiên c u vƠ phát tri n Công ngh Ph n m m, n i đƣ t o u ki n cho h c t p su t th i gian h c cao h c Tôi xin bƠy t lòng cám n sơu s c đ n anh ch , b n bè l p K11T2 đƣ cho nh ng l i đ ng viên, góp ý vƠ giúp đ trình h c t p vƠ th c hi n lu n v n Tôi xin c m n th y, anh ch vƠ b n Trung tơm nghiên c u vƠ phát tri n Công ngh ph n m m cho nh ng l i đ ng viên, khích l , nh ng góp ý sơu s c vƠ nh ng đ nh h ng đ s m hoƠn thƠnh lu n v n nƠy Xin c m n Khoa Công ngh thông tin, Tr ng i h c Công ngh , HQGHN t o u ki n t t cho h c t p vƠ công tác su t trình h c t p vƠ lƠm lu n v n Cu i xin bƠy t lòng bi t n sơu s c t i gia đình, n i ng h , giúp đ vƠ bên m i hoƠn c nh khó kh n HƠ N i, tháng 11/2007 Phan V n Thu n L IăCAMă OAN Tôi xin cam đoan k t qu đ t đ nhơn tôi, không chép l i c a ng c lu n v n lƠ s n ph m c a riêng cá i khác Lu n v n lƠ k t qu c a trình h c t p, nghiên c u vƠ lƠm vi c nghiêm túc su t h n hai n m cao h c Trong toƠn b n i dung c a lu n v n, nh ng u đ c trình bƠy ho c lƠ k t qu nghiên c u c a cá nhơn ho c lƠ k t qu t ng h p t nhi u ngu n tƠi li u khác Nh ng k t qu nghiên c u nƠo c a cá nhơn đ u đ c ch rõ rƠng lu n v n Các thông tin t ng h p hay k t qu l y t nhi u ngu n tƠi li u khác đ c trích d n m t cách đ y đ vƠ h p lý T t c tƠi li u tham kh o đ u có xu t x rõ rƠng vƠ đ c trích d n h p pháp Tôi xin hoƠn toƠn ch u trách nhi m vƠ ch u m i hình th c k lu t theo quy đ nh cho l i cam đoan c a HƠ N i, tháng 11/2007 Phan V n Thu n M CăL C M U CH NG - T ng quan 1.1 t v n đ 1.2 N i dung vƠ c u trúc c a lu n v n 10 CH NG - Khái quát m t s ph ng pháp phơn vùng nh vƠ kh nghiêng Error! Bookmark not defined 2.1 T ng quan v x lý bi u m u Error! Bookmark not defined 2.1.1 Các đ c tr ng c a bi u m u Error! Bookmark not defined 2.1.2 Quá trình x lý bi u m u d a Ngôn ng mô t bi u m u Error! Bookmark not defined 2.1.3 Quá trình x lý bi u m u d a đ ng ký bi u m u (Form registration) Error! Bookmark not defined 2.1.4 H th ng x lý bi u m u Error! Bookmark not defined 2.2 Các k thu t th ng đ c s d ng nh n d ng c u trúc bi u m u Error! Bookmark not defined 2.2.1 Ch nh đ nghiêng c a v n b n bi u m u Error! Bookmark not defined 2.2.1.1 2.2.1.2 Phơn tích hình nh c a phép chi u Error! Bookmark not defined Xác đ nh góc nghiêng d a vƠo bi n đ i Hough Error! Bookmark not defined 2.2.1.3 2.2.1.4 2.2.1.5 defined 2.2.1.6 Phơn c m hƠng xóm g n nh t Error! Bookmark not defined S t ng quan c a đ ng th ng Error! Bookmark not defined M t s k thu t tính góc nghiêng khác Error! Bookmark not B ng t ng k t v thu t toán xác đ nh góc nghiêng .Error! Bookmark not defined 2.2.2 Phơn tích trang Error! Bookmark not defined 2.2.2.1 2.2.2.2 defined 2.2.2.3 defined 2.2.2.4 2.2.2.5 Các k thu t phơn vùng ký t Error! Bookmark not defined Các k thu t phơn vùng trang v n b n Error! Bookmark not Các k thu t k t h p phơn vùng/phơn l p Error! Bookmark not Các k thu t phơn l p kh i Error! Bookmark not defined B ng t ng k t v k thu t phơn tích trang Error! Bookmark not defined CH NG - xu t gi i pháp s d ng bi u m u đ ng Error! Bookmark not defined 3.1 H th ng x lý bi u m u đ ng Error! Bookmark not defined 3.1.1 Gi i thi u v h th ng x lý bi u m u Error! Bookmark not defined 3.1.2 So sánh v i ph ng pháp truy n th ng Error! Bookmark not defined 3.1.3 Ph ng pháp nhơn d ng c b n Error! Bookmark not defined 3.1.4 Thi t k h th ng Error! Bookmark not defined 3.1.4.1 3.1.4.2 3.1.4.3 3.1.4.4 Ki n trúc h th ng Error! Bookmark not defined H th ng chu n b bi u m u Error! Bookmark not defined H th ng x lý bi u m u Error! Bookmark not defined ng d ng Error! Bookmark not defined 3.2 Các thu t toán x lý nh áp d ng cho x lý bi u m u đ ng Error! Bookmark not defined 3.2.1 Khái ni m bi u m u đ ng Error! Bookmark not defined 3.2.2 L c đ x lý bi u m u đ ng Error! Bookmark not defined 3.2.3 Các ph ng pháp tách ch vi t tay kh i khung n .Error! Bookmark not defined 3.2.3.1 3.2.3.2 Tìm hi u thu t toán tách c b n Error! Bookmark not defined Tách ch vi t tay kh i khung n Error! Bookmark not defined 3.2.4.1 3.2.4.2 Ph Ph 3.2.4 Xác đ nh v trí khung n Error! Bookmark not defined ng pháp chi u Error! Bookmark not defined ng pháp b qua kho ng tr ng Error! Bookmark not defined 3.2.5 Xác đ nh thông tin n ch a khung n Error! Bookmark not defined 3.3 Các thu t toán khác áp d ng cho bi u m u đ ng Error! Bookmark not defined 3.3.1 Thu t toán bóc vi n Error! Bookmark not defined 3.3.2 Thu t toán xác đ nh góc nghiêng Error! Bookmark not defined 3.3.2.1 3.3.2.2 Thu t toán s d ng phép chi u Error! Bookmark not defined Thu t toán s d ng đ ng th ng dƠy Error! Bookmark not defined 3.4 Th c nghi m Error! Bookmark not defined 3.4.1 Môi tr ng th c nghi m Error! Bookmark not defined 3.4.2 Th c nghi m đ i v i thu t toán c b n bi u m u đ ng Error! Bookmark not defined 3.4.2.1 Th c nghi m tách ch vi t tay kh i khung n Error! Bookmark not defined 3.4.2.2 Th c nghi m xác đ nh v trí khung n thông tin .Error! Bookmark not defined 3.4.2.3 Th c nghi m xác đ nh c u trúc m nh t ng khung Error! Bookmark not defined 3.4.3 Th c nghi m đ i v i thu t toán khác Error! Bookmark not defined 3.4.3.1 Xác đ nh góc nghiêng c a nh theo ph ng pháp chi u Error! Bookmark not defined 3.4.3.2 Th c nghi m nh n d ng đ ng th ng dƠy Error! Bookmark not defined K t lu n Error! Bookmark not defined o TÀI LI U THAM KH O 12 DANHăM CăHÌNHă NH ảình 2.1: L c đ trình x lý bi u m u d a Ngôn ng mô t bi u m u Error! Bookmark not defined ảình 2.2: M t h th ng x lý bi u m u v n b n Error! Bookmark not defined ảình 2.3: (a) nh tr c kh nghiêng; (b) nh sau kh nghiêng Error! Bookmark not defined ảình 2.4: (a), (b), (c) : Các đ i t ng nh ; (d), (e), (f) : Phân c m đ i t ng [17] Error! Bookmark not defined ảình 3.1 Phân tách ch vi t tay khung Error! Bookmark not defined ảình 3.2 ả th ng bi u m u đ ng Error! Bookmark not defined ảình 3.3: Data set Error! Bookmark not defined ảình 3.4: Vùng mã hóa thông tin Error! Bookmark not defined ảình 3.5: M t minh h a v bi u m u đ ng Error! Bookmark not defined ảình 3.6: Lu ng x lý Error! Bookmark not defined ảình 3.7: ảình nh c a ch m nh Error! Bookmark not defined ảình 3.8: M t c u trúc c a khung Error! Bookmark not defined ảình 3.9: M t bi u m u đ ng Error! Bookmark not defined ảình 3.10: M t s c u trúc ch m nh Error! Bookmark not defined ảình 3.11: M t l c đ x lý bi u m u đ ng Error! Bookmark not defined ảình 3.12 : Khung tr c tách Error! Bookmark not defined ảình 3.13 : Khung sau tách ch vi t tay Error! Bookmark not defined ảình 3.14 : Ch vi t tay sau tách khung Error! Bookmark not defined ảình 3.15 : Phép chi u theo chi u ngang Error! Bookmark not defined ảình 3.16 : Phép chi u khung theo chi u d c Error! Bookmark not defined ảình 3.17 : Phép chi u theo chi u d c m nh Error! Bookmark not defined ảình 3.18: nh scan có đ ng vi n màu đen Error! Bookmark not defined ảình 3.19: Các ki u hình d ng khác c a c m, m i màu t ng ng v i m t c m Error! Bookmark not defined ảình 3.20: Mô t m lân c n tr c ti p Error! Bookmark not defined ảình 3.21: Mô t m lân c n Error! Bookmark not defined ảình 3.22: Mô t m n i Error! Bookmark not defined ảình 3.23: nh scan có đ ng vi n màu đen nh sau bóc vi n đen Error! Bookmark not defined ảình 3.24: (a) nh scan, đ ng màu đ đ ng chi u góc nghiêng (b) nh đ c x p x b i hình bình hành Error! Bookmark not defined ảình 3.25: (a) nh scan (b) (c) (d) nh đ ng chi u đen tr ng góc nghiêng -2.50, -3.50, 20 Error! Bookmark not defined ảình 3.26: (a) nh scan (b) nh sau xác góc nghiêng Error! Bookmark not defined ảình 3.27 nh tr c sau xoay chi u Error! Bookmark not defined ảình 3.28 Phi u tr l i đ c quét ng c chi u Error! Bookmark not defined M U Nh p d li u t đ ng lƠ bƠi toán ngƠy cƠng thu hút nhi u s ý vƠ đ u t nghiên c u b i đơy th t s lƠ m t v n đ quan tr ng, c n thi t kh n ng áp d ng r ng rƣi vƠo th c t c ng nh hi u qu mƠ mang l i Trong bƠi toán nƠy, kh nhi u, kh nghiêng vƠ phơn vùng nh lƠ m t ph n có vai trò đ c bi t quan tr ng Ch c n ng c a lƠ xác nh, tách vùng đ c nh p thông tin, tách ch vi t tay kh i khung n thông tin đ lƠm đ u vƠo cho module nh n d ng ch Trong lu n v n nƠy trình bƠy m t ph ng pháp s d ng “c u trúc ch m nh ” đ t o khung n thông tin C u trúc ch m nh nƠy đ c t o b i r t nhi u ch m nh ho c đo n th ng nh Ph ng pháp c a có nh ng đ c m n i b t sau:  Không c n thi t k bi u m u có mƠu s c mƠ v n tách ký t ch vi t tay kh i khung n  D dƠng tách ph n ch vi t tay kh i khung n m t cách nhanh chóng vƠ d dƠng b ng thu t toán x lý nh đ n gi n, đ c bi t tr ng h p ch vi t tay đè lên khung  Chi phí cho x lý bi u m u lƠ th p  Không c n bi t tr c v trí logic c a khung n ch vƠ tìm cách x lý t đ ng ký t khung Chúng đƣ ti n hƠnh th c nghi m nhi u m u bi u m u đ ng vƠ thu đ c nh ng k t qu r t kh quan T khóa – X lý nh, Phân tích trang tài li u, Nh n d ng, Bi u m u, Phép toán hình thái, Active form 10 CH 1.1 NGă1ă- T ngăquan tăv năđ Trong th c t , công vi c nh p d li u chi m m t chi phí l n kh i l ng d li u ph i nh p vƠ công s c b đ đ m b o vi c nh p có đ xác cao Vì th t lơu v n đ nh p li u t đ ng đƣ đ c đ u t nhi u Ngu n d li u ph bi n nh t lƠ v n b n gi y, gi i pháp ch y u lƠ ph i l y nh vƠ nh n d ng Nh n d ng lƠ bƠi toán đƣ xu t hi n lơu vƠ đƣ đ t đ c nhi u thƠnh t u to l n Tuy nhiên nh n d ng m t v n b n b t kì bao g m c v n b n có l n ch vi t tay hay hình nh lƠ m t bƠi toán khó vƠ hi n v n ch a th t s có gi i pháp hoƠn ch nh Trên th gi i, hi n đƣ có nhi u ng d ng liên quan đ n v n đ nh n d ng v n b n hay nh p d li u t đ ng Có th k đ n nh : s n ph m FineReader, Scan To Office c a hƣng ABBYY, Smart scan Xpress c a Pegasus Image, ng d ng ch m thi t đ ng ầ Vi t Nam c ng đƣ có ng d ng nh n d ng v n b n nh VNDocR c a Vi n Công ngh Thông tin hay ImageScan c a CardPro ơy lƠ ng d ng nh n d ng ch in Vi c nh n d ng ch vi t tay lƠ m t thách th c M t s nghiên c u v nh n d ng ch vi t tay đƣ đ c th c hi n t i Vi n CNTT vƠ B môn Công ngh Ph n m m Tuy nhiên ng d ng nƠy hi n v n r t nhi u h n ch kh n ng nh n d ng ch vi t tay ch a đ t đ c đ xác c n thi t đ có th áp d ng r ng rƣi th c t Có hai đ i t ph ng v n b n c n nh n d ng có đ t tr ng khác đòi h i có ng pháp x lý khác ó lƠ nh n d ng v n b n phi c u trúc vƠ nh n d ng v n b n ki u bi u m u v i d li u ch đ c s p x p nh ng vùng xác đ nh Cùng v i s phát tri n c a công ngh x lý nh hi n nay, thu t toán nh n d ng ngƠy cƠng xác vƠ đ a đ ch vi t tay c ng có th đ t đ c k t qu đáng tin c y Ngay c đ i v i c đ xác cao v i u ki n lƠ ch nh n d ng t ng ch riêng bi t vƠ ch vi t đ p V i v n b n thông th ng, ta khó có th đ t 13 Ch ng nƠy trình bƠy v ph n vi c mƠ đƣ th c hi n đ tƠi chung: Gi i pháp s d ng h th ng x lý bi u m u đ ng cho vi c phơn vùng nh vƠ tách ch vi t tay N i dung c a ch ng t p trung vƠo: a khái ni m v bi u m u đ ng vƠ h th ng x lý bi u m u  đ ng  Trình bƠy thu t toán c b n ng d ng cho vi c nh n d ng bi u m u đ ng  ánh giá u vƠ nh c m c a thu t toán nƠy  Mô t chi ti t trình th c nghi m thu t toán đƣ đ xu t Ch ngă4:ăK tălu nă Ch ng b n t ng k t l i nh ng k t qu đ t đ ti p t c th c hi n t ng lai c vƠ nh ng vi c c n đ c 14 o TÀIăLI UăTHAMăKH O TƠiăli uăti ngăVi t STT [1] Phan V n Thu n & Ngô Qu c T o:“ K t h p m t s k thu t x lý nh nơng cao cho x lý bi u m u đ ng vƠ ng d ng”, ả i th o khoa h c qu c gia l n th 3-Nghiên c u c b n ng d ng công ngh thông tin, 10-2007 [2] Phan V n Thu n & Ơo Thanh Khi t: “X lý t đ ng phi u u tra”, Khóa lu n t t nghi p, đ i h c Công ngh , đ i h c Qu c gia ảà n i, 5-2004 [3] Tr n Thanh Phúc & inh V n Ph ng: “ Nghiên c u vƠ xơy d ng h th ng nh p tƠi li u t đ ng b ng nh n d ng quang h c”, Khóa lu n t t nghi p , đ i h c Công ngh , đ i h c Qu c gia ảà n i, 5-2006 TƠiăli uăti 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