Xử lý ảnh số - Nén dữ liệu ảnh part 4 pptx

... (nhi.phˆan) tu..nhiˆen m-bit l`a m˜a trong d¯´o mˆo˜isu..kiˆe.n (chˇa˙’ng ha.n gi´a tri.x´am) d¯u.o..c m˜a ho´abo.˙’i chuˆo˜i bit d¯ˆo.d`ai m. 143 ••••••••••••••••.......................................................................................................... ... .........................l2(rk)01/72/73/ 74/ 75/76/710.00.1250.25pr(rk)0123 4 56l2(rk).................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................. ... ho´a a˙’nhl`aLavg=7k=0l2(rk)pr(rk)= 2(0.19) + 2(0.25) + 2(0.21) + 3(0.16) + 4( 0.08) + 5(0.06) + 6(0.03) + 6(0.02)=2.7 bit.Suy ra tı˙’lˆe.n´en l`a CR=3/2.7=1.11. Do...

... kˆenh v`a gia˙’im˜akˆenh d¯´ong vai tr`o quan tro.ng trong to`an bˆo.qu´a tr`ınh m˜ah´oa-gia˙’i m˜a khi kˆenh truyˆe`n c´o nhiˆe˜u hoˇa.cc´olˆo˜i. Ch´ung d¯u.o..c thiˆe´tkˆe´d¯ ... xuˆa´thiˆe.nd¯u˙’´ıt th`ı c´o thˆe˙’phu.chˆo`id¯u.o..cd˜u.liˆe.u ban d¯ˆa`u.D - ˆe˙’gia˙’im˜ad˜u.liˆe.ud¯u.o..c m˜a h´oa bˇa`ng phu.o.ng ph´ap Hamming, bˆo.gia˙’i ... nhˇa`m xˆay du..ng c´ac t`u.m˜a nhi.phˆanci,i=0, 1, ,L− 1, tu.o.ng ´u.ng mˆo.t-mˆo.tv´o.imˆo˜i gi´a tri.ai. Mu.cd¯´ıch cu˙’a m˜a ho´a l`athiˆe´tkˆe´bˆo.m˜a...

... truyˆe`n qua n´o.158Khi d¯´ov = Qz. (6 .4) Ma trˆa.n Q v´o.i c´ac phˆa`ntu.˙’qkj= P(bk|aj)go.il`ama trˆa.nbiˆe´nd¯ˆo˙’i kˆenh thuˆa.n.D - ˆe˙’x´ac d¯i.nh kha˙’nˇang ... ngu.`o.isu.˙’du.ng thˆongtin quan s´at mˆo.t t´ın hiˆe.urabk. Phu.o.ng tr`ınh (6 .4) x´ac d¯i.nh h`am phˆan bˆo´cu˙’a c´ack´yhiˆe.u nguˆo`n khi bkd¯ u.o..c quan ... cˆa´pco.so.˙’to´an ho.c tra˙’l`o.i cˆau ho˙’i n`ay v`anh˜u.ng vˆa´nd¯ˆe`liˆen quan.6.3.1 D - o thˆong tinTiˆe`nd¯ˆe`co.ba˙’ncu˙’a l´y thuyˆe´t thˆong tin l`a c´o thˆe˙’mˆo...

... 1.58 2 1 1Mo.˙’rˆo.ng th´u.haiα1a1a1 4/ 9 1.17 2 0 1α2a1a22/9 2.17 3 10 2α3a2a12/9 2.17 3 110 3α 4 a2a21/9 3.17 4 111 3Ba˙’ng 6.2: V´ı du.m˜a ho´a nguˆo`nmo.˙’rˆo.ng.quan ... trung b`ınh cu˙’a qu´a tr`ınh m˜aho´a-gia˙’i m˜a d¯u.o..c mˆo h`ınh bo.˙’i ma trˆa.n Q. Thu˙’tu.c m˜a ho´a-gia˙’i m˜a go.il`aD−chˆa´p1 64 ... (ain).D - ˇa.t z=(P (αi1),P(αi2), ,P(αJn))t. Ta c´o entropy cu˙’a nguˆo`nbˇa`ngH(z)=−Jni=1P (αi) log P(αi).160K´yhiˆe.u P (αi) I(αi) l(αi)T`u.m˜a D - ˆo.d`aiαinguˆo`nMo.˙’rˆo.ng...

... cˆo.t tru.´o.c d¯´o ta d¯u.o..cbiˆe˙’udiˆe˜n21 0 0 74 74 74 0 021 0 0 74 74 74 0 021 0 0 74 74 74 0 021 0 0 74 74 74 0 0169nhˆa.nd¯u.o..c nˆe´u distortion trung b`ınh ... (hay entropy) cu˙’aa˙’nh 8 bit:21 21 21 95 169 243 243 243 21 21 21 95 169 243 243 243 21 21 21 95 169 243 243 243 21 21 21 95 169 243 243 243 C´ach tu.o.ng d¯ˆo´id¯o.n gia˙’n l`a ... cu˙’anguˆo`n):Cˇa.pm´u.c x´am Tˆa`nsˆo´X´ac suˆa´t(21, 21) 8 1 /4 (21, 95) 4 1/8(95, 169) 4 1/8(169, 243 ) 4 1/8( 243 , 243 ) 8 1 /4 ( 243 , 21) 4 1/8Kˆe´t qua˙’u.´o.clu.o..ng entropy theo...

... 1110a210.01 10100 011011 10 1000 C00C00C00 111 111 110 00 00 1111Entropy 4. 0D - ˆo.d`aitrung b`ınh 5.0 4. 05 4. 24 4.65 4. 59 4. 13Ba˙’ng 6.3: C´ac m˜a c´o d¯ˆo.d`ai thay d¯ˆo˙’i.176 ...................................................................................................................................................................................................................................................................................................................................................................................................... ... go.nK´yhiˆe.uX´ac suˆa´t12 34 a2a6a1a 4 a3a50 .4 0.30.10.10.060. 04 . ...................................0 .4 0.30.10.10.1 ... suˆa´tT`u.m˜a12 34 a2a6a1a 4 a3a50 .4 0.30.10.10.060. 04 10001101000101001011 ................................... 0 .41 0.3000.1...

... suˆa´t Khoa˙’ng kho.˙’ita.oa10.2 [0.0, 0.2)a20.2 [0.2, 0 .4) a30 .4 [0 .4, 0.8)a 4 0.2 [0.8, 1.0)Ba˙’ng 6 .4: V´ı du.m˜a ho´a sˆo´ho.c.th`anh bˆo´nv`ung con du..a trˆen ... [0. 04, 0.08); k´y hiˆe.u a3thu he.p khoa˙’ng J3th`anh J 4 := [0.056, 0.072) v`asau d¯´o th`anh J5:= [0.06 24, 0.0688). K´yhiˆe.u nguˆo`n cuˆo´ic`ung trong thˆong b´ao (l`a a 4 )xem ... mˆo.tt`u.m˜a 1-bit hoˇa.ct`u.m˜a 2-bit. D˜ı nhiˆen t`u.m˜a ´u.ng v´o.ic´ac khˆo´ihˆo˜nho..pd¯u.o..c xem nhu.l`a tiˆe`ntˆo´m`a sau d¯´o l`a mˆo.tmˆa˜u mn-bit biˆe˙’udiˆe˜ncho...

... −→ −→ −→ −→ −→ −→↓↓↓↓↓←−←−←−←−←−←−←−↑↑↑↑↑↑↓◦◦◦◦••••++++IP 1−→←−IP 4 ↑↓↑↓↑−→ −→↓←−←−IP 3←−−→↓↑IP 2H`ınh 6.12: Bˆo´n IP v`a c´ac chu tuyˆe´ntu.o.ng ... (d¯iˆe`u n`ay d¯u.o..c x´ac d¯i.nhbˇa`ng c´ach kiˆe˙’m tra dˆa´uhiˆe.ucu˙’a n´o-nˆe´u khˆong l`a I ngh˜ıa l`a n´o d¯u.o..cviˆe´ng thˇam lˆa`nth ´u.hai) d¯ˆa`u ... dˆa´uhiˆe.ucu˙’a n´o theo H`ınh 6.13, nhu.ng sau d¯´ocˆa.p nhˆa.tla.i theo H`ınh 6. 14. Khˆong c´o phˆa`ntu.˙’n`ao d¯u.o..cviˆe´ng thˇam ho.n hai lˆa`n, ngoa.itr`u.phˆa`ntu.˙’IP...

... 16 11 10 16 24 40 51 6112 12 14 19 26 58 60 55 14 13 16 24 40 57 69 56 14 17 22 29 51 87 80 6218 22 37 56 68 109 103 77 24 35 55 64 81 1 04 113 92 49 64 78 87 103 121 120 10172 ... nhau.1 24 125 122 120 122 119 117 118121 121 120 119 119 120 120 118126 1 24 123 122 121 121 120 1201 24 1 24 125 125 126 125 1 24 1 24 127 127 128 129 130 128 127 125 143 142 143 142 140 139 139 ... 118121 121 120 119 119 118 117 1171 24 1 24 123 122 122 121 120 120130 130 129 129 128 128 128 127 141 141 140 140 139 138 138 137152 152 151 151 150 149 149 148 159 158 158 157 157 156 155 155Ba˙’ng...

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