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Erosion (morphology)

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Example of erosion on a grayscale image using a 5x5 flat structuring element. The top figure demonstrates the application of the structuring element window to the individual pixels of the original image. The bottom figure shows the resulting eroded
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In other words the erosion of a point is the minimum of the points in its neighborhood, with that neighborhood defined by the structuring element. In this way it is similar to many other kinds of image filters like the
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The basic idea in binary morphology is to probe an image with a simple, pre-defined shape, drawing conclusions on how this shape fits or misses the shapes in the image. This simple "probe" is called
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the origin of B, if B is completely contained by A the pixel is retained, else deleted.
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from which all other morphological operations are based. It was originally defined for
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has a center (e.g., a disk or a square), and this center is located on the origin of
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inside A that the pixels values are retained, otherwise it gets deleted or eroded.
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The erosion of the dark-blue square by a disk, resulting in the light-blue square.
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Image Analysis and Mathematical Morphology, Volume 2: Theoretical Advances
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that distributes over the infimum, and preserves the universe. I.e.:
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can be understood as the locus of points reached by the center of
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for probing and reducing the shapes contained in the input image.
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Assuming that the origin B is at its center, for each pixel in A
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be a complete lattice, with infimum and supremum symbolized by
699:{\displaystyle (A\ominus B)\ominus C=A\ominus (B\oplus C)} 241:{\displaystyle A\ominus B=\{z\in E\mid B_{z}\subseteq A\}} 1470:
Morphological Image Analysis; Principles and Applications
1487:, 2nd ed. Upper Saddle River, N.J.: Prentice Hall, 2002. 41:) is one of two fundamental operations (the other being 481:
Suppose A is a 13 x 13 matrix and B is a 3 x 3 matrix:
1361: 1277: 1242: 1210: 1170: 1150: 1126: 1106: 1074: 919: 872: 852: 826: 813:{\displaystyle \mathbb {R} \cup \{\infty ,-\infty \}} 783: 712: 650: 615: 562: 536: 399: 328: 271: 191: 121: 86: 1382: 1345: 1260: 1228: 1189: 1156: 1132: 1112: 1092: 1004: 881: 858: 834: 812: 718: 698: 633: 586: 548: 444:{\displaystyle A\ominus B=\bigcap _{b\in B}A_{-b}} 443: 343: 314: 240: 136: 101: 1456:An Introduction to Morphological Image Processing 948: 866:is an element larger than any real number, and 1005:{\displaystyle (f\ominus b)(x)=\inf _{y\in B}} 587:{\displaystyle A\ominus B\subseteq C\ominus B} 73:In binary morphology, an image is viewed as a 162:be a Euclidean space or an integer grid, and 8: 1184: 1171: 889:is an element smaller than any real number. 807: 792: 309: 285: 235: 204: 1261:{\displaystyle \varepsilon :L\rightarrow L} 499:of A by B is given by this 13 x 13 matrix. 1428:Image Analysis and Mathematical Morphology 16:Basic operation in mathematical morphology 1360: 1332: 1322: 1298: 1282: 1276: 1241: 1209: 1178: 1169: 1149: 1125: 1105: 1073: 951: 918: 896:and the grayscale structuring element by 871: 851: 828: 827: 825: 785: 784: 782: 711: 649: 614: 561: 535: 432: 416: 398: 327: 276: 270: 223: 190: 128: 124: 123: 120: 93: 89: 88: 85: 315:{\displaystyle B_{z}=\{b+z\mid b\in B\}} 469:This is more generally also known as a 61:. The erosion operation usually uses a 634:{\displaystyle A\ominus B\subseteq A} 7: 601:belongs to the structuring element 1151: 876: 853: 804: 795: 329: 14: 1383:{\displaystyle \varepsilon (U)=U} 1197:be a collection of elements from 393:is also given by the expression: 1483:R. C. Gonzalez and R. E. Woods, 137:{\displaystyle \mathbb {Z} ^{d}} 102:{\displaystyle \mathbb {R} ^{d}} 1057:. In particular, it contains a 506:This means that only when B is 1371: 1365: 1304: 1291: 1252: 1223: 1211: 1164:, respectively. Moreover, let 1087: 1075: 999: 996: 990: 981: 969: 963: 941: 935: 932: 920: 693: 681: 663: 651: 344:{\displaystyle \forall z\in E} 47:morphological image processing 1: 1038:Erosions on complete lattices 354:When the structuring element 1049:, where every subset has an 835:{\displaystyle \mathbb {R} } 549:{\displaystyle A\subseteq C} 57:images, and subsequently to 1065:(also denoted "universe"). 458:denotes the translation of 178:by the structuring element 1522: 1157:{\displaystyle \emptyset } 53:, later being extended to 18: 1229:{\displaystyle (L,\leq )} 1190:{\displaystyle \{X_{i}\}} 1093:{\displaystyle (L,\leq )} 1485:Digital image processing 1458:by Edward R. Dougherty, 1018:where "inf" denotes the 882:{\displaystyle -\infty } 37:(usually represented by 21:Erosion (disambiguation) 1506:Mathematical morphology 1401:Mathematical morphology 1113:{\displaystyle \wedge } 859:{\displaystyle \infty } 762:morphology, images are 719:{\displaystyle \oplus } 265:by the vector z, i.e., 1384: 1347: 1262: 1230: 1191: 1158: 1134: 1114: 1094: 1047:partially ordered sets 1006: 883: 860: 836: 814: 755: 728:morphological dilation 720: 700: 644:The erosion satisfies 635: 605:, then the erosion is 588: 550: 445: 362:, then the erosion of 345: 316: 261:is the translation of 242: 138: 103: 31: 1385: 1348: 1263: 1231: 1192: 1159: 1135: 1133:{\displaystyle \vee } 1115: 1095: 1007: 892:Denoting an image by 884: 861: 837: 815: 752: 721: 701: 636: 589: 551: 521:translation invariant 446: 346: 317: 243: 144:, for some dimension 139: 104: 29: 1359: 1275: 1240: 1208: 1168: 1148: 1124: 1104: 1072: 917: 870: 850: 824: 781: 710: 648: 613: 560: 534: 508:completely contained 471:Minkowski difference 397: 326: 269: 189: 174:of the binary image 119: 84: 19:For other uses, see 153:structuring element 63:structuring element 1472:by Pierre Soille, 1380: 1343: 1327: 1287: 1258: 1226: 1187: 1154: 1130: 1110: 1090: 1002: 962: 879: 856: 832: 810: 756: 716: 696: 631: 584: 546: 441: 427: 341: 312: 238: 166:a binary image in 134: 99: 32: 1318: 1278: 1043:Complete lattices 947: 745:Grayscale erosion 597:If the origin of 412: 59:complete lattices 1513: 1501:Digital geometry 1389: 1387: 1386: 1381: 1352: 1350: 1349: 1344: 1342: 1338: 1337: 1336: 1326: 1303: 1302: 1286: 1267: 1265: 1264: 1259: 1236:is any operator 1235: 1233: 1232: 1227: 1196: 1194: 1193: 1188: 1183: 1182: 1163: 1161: 1160: 1155: 1139: 1137: 1136: 1131: 1119: 1117: 1116: 1111: 1099: 1097: 1096: 1091: 1063:greatest element 1011: 1009: 1008: 1003: 961: 888: 886: 885: 880: 865: 863: 862: 857: 841: 839: 838: 833: 831: 819: 817: 816: 811: 788: 739:set intersection 725: 723: 722: 717: 705: 703: 702: 697: 640: 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1392: 1391: 1379: 1376: 1373: 1370: 1367: 1364: 1354: 1341: 1335: 1331: 1325: 1321: 1316: 1312: 1309: 1306: 1301: 1297: 1293: 1290: 1285: 1281: 1257: 1254: 1251: 1248: 1245: 1225: 1222: 1219: 1216: 1213: 1204:An erosion in 1186: 1181: 1177: 1173: 1153: 1129: 1109: 1089: 1086: 1083: 1080: 1077: 1039: 1036: 1016: 1015: 1014: 1013: 1001: 998: 995: 992: 989: 986: 983: 980: 977: 974: 971: 968: 965: 960: 957: 954: 950: 946: 943: 940: 937: 934: 931: 928: 925: 922: 878: 875: 855: 842:is the set of 830: 809: 806: 803: 800: 797: 794: 791: 787: 746: 743: 742: 741: 731: 715: 695: 692: 689: 686: 683: 680: 677: 674: 671: 668: 665: 662: 659: 656: 653: 642: 630: 627: 624: 621: 618: 607:anti-extensive 595: 583: 580: 577: 574: 571: 568: 565: 545: 542: 539: 530:, that is, if 524: 515: 512: 501: 495:Therefore the 483: 478: 475: 454: 438: 435: 431: 425: 422: 419: 415: 411: 408: 405: 402: 340: 337: 334: 331: 311: 308: 305: 302: 299: 296: 293: 290: 287: 284: 279: 275: 256: 250: 249: 237: 234: 231: 226: 222: 218: 215: 212: 209: 206: 203: 200: 197: 194: 131: 126: 96: 91: 70: 69:Binary erosion 67: 15: 13: 10: 9: 6: 4: 3: 2: 1518: 1507: 1504: 1502: 1499: 1498: 1496: 1486: 1482: 1479: 1478:3-540-65671-5 1475: 1471: 1468: 1465: 1464:0-8194-0845-X 1461: 1457: 1454: 1451: 1450:0-12-637241-1 1447: 1443: 1440: 1437: 1436:0-12-637240-3 1433: 1429: 1426: 1425: 1421: 1417: 1414: 1412: 1409: 1407: 1404: 1402: 1399: 1398: 1394: 1377: 1374: 1368: 1362: 1355: 1339: 1333: 1329: 1323: 1319: 1314: 1310: 1307: 1299: 1295: 1288: 1283: 1279: 1271: 1270: 1269: 1255: 1249: 1246: 1243: 1220: 1217: 1214: 1202: 1200: 1179: 1175: 1143: 1127: 1107: 1084: 1081: 1078: 1066: 1064: 1060: 1059:least element 1056: 1052: 1048: 1044: 1037: 1035: 1033: 1029: 1028:median filter 1023: 1021: 993: 987: 984: 978: 975: 972: 966: 958: 955: 952: 944: 938: 929: 926: 923: 913: 912: 911: 910: 909: 907: 903: 899: 895: 890: 873: 845: 801: 798: 789: 776: 773: 769: 765: 761: 751: 744: 740: 736: 732: 729: 713: 690: 687: 684: 678: 675: 672: 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38: 34: 33: 490:superimpose 1495:Categories 1422:References 766:mapping a 528:increasing 514:Properties 1363:ε 1320:⋀ 1311:ε 1289:ε 1280:⋀ 1253:→ 1244:ε 1221:≤ 1152:∅ 1128:∨ 1108:∧ 1085:≤ 985:− 956:∈ 927:⊖ 877:∞ 874:− 854:∞ 805:∞ 802:− 796:∞ 790:∪ 764:functions 760:grayscale 714:⊕ 688:⊕ 679:⊖ 667:⊖ 658:⊖ 626:⊆ 620:⊖ 579:⊖ 573:⊆ 567:⊖ 541:⊆ 434:− 421:∈ 414:⋂ 404:⊖ 336:∈ 330:∀ 304:∈ 298:∣ 230:⊆ 217:∣ 211:∈ 196:⊖ 55:grayscale 1406:Dilation 1395:See also 1055:supremum 1030:and the 820:, where 706:, where 609:, i.e., 451:, where 43:dilation 1416:Closing 1411:Opening 1051:infimum 1020:infimum 556:, then 497:Erosion 477:Example 172:erosion 111:integer 109:or the 35:Erosion 1480:(1999) 1476:  1466:(1992) 1462:  1452:(1988) 1448:  1438:(1982) 1434:  1061:and a 1053:and a 754:image. 526:It is 252:where 170:. The 75:subset 844:reals 777:into 737:over 374:when 77:of a 45:) in 1474:ISBN 1460:ISBN 1446:ISBN 1432:ISBN 1144:and 1120:and 1068:Let 1045:are 898:b(x) 894:f(x) 772:grid 158:Let 114:grid 949:inf 904:by 770:or 758:In 462:by 389:by 366:by 1497:: 1201:. 1034:. 1022:. 846:, 473:. 466:. 464:-b 455:−b 351:. 322:, 148:. 1390:. 1378:U 1375:= 1372:) 1369:U 1366:( 1353:, 1340:) 1334:i 1330:X 1324:i 1315:( 1308:= 1305:) 1300:i 1296:X 1292:( 1284:i 1256:L 1250:L 1247:: 1224:) 1218:, 1215:L 1212:( 1199:L 1185:} 1180:i 1176:X 1172:{ 1142:U 1088:) 1082:, 1079:L 1076:( 1012:, 1000:] 997:) 994:y 991:( 988:b 982:) 979:y 976:+ 973:x 970:( 967:f 964:[ 959:B 953:y 945:= 942:) 939:x 936:( 933:) 930:b 924:f 921:( 906:b 902:f 829:R 808:} 799:, 793:{ 786:R 775:E 730:. 694:) 691:C 685:B 682:( 676:A 673:= 670:C 664:) 661:B 655:A 652:( 641:. 629:A 623:B 617:A 603:B 599:E 594:. 582:B 576:C 570:B 564:A 544:C 538:A 523:. 460:A 453:A 437:b 430:A 424:B 418:b 410:= 407:B 401:A 391:B 387:A 380:A 376:B 372:B 368:B 364:A 360:E 356:B 339:E 333:z 310:} 307:B 301:b 295:z 292:+ 289:b 286:{ 283:= 278:z 274:B 263:B 258:z 254:B 248:, 236:} 233:A 225:z 221:B 214:E 208:z 205:{ 202:= 199:B 193:A 180:B 176:A 168:E 164:A 160:E 146:d 130:d 125:Z 95:d 90:R 39:⊖ 23:.

Index

Erosion (disambiguation)

dilation
morphological image processing
binary images
grayscale
complete lattices
structuring element
subset
Euclidean space
integer
grid
structuring element
Minkowski difference
translation invariant
increasing
morphological dilation
distributive
set intersection

grayscale
functions
Euclidean space
grid
reals
infimum
median filter
gaussian filter
Complete lattices
partially ordered sets

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