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11.2 Knowledge in Image Classification. . . . . . . . . . . 449
11.2.1 Type of Knowledge . . . . . . . . . . . . . . . . 449
11.2.2 Spectral Knowledge . . . . . . . . . . . . . . . 451
11.2.3 Spatial Knowledge . . . . . . . . . . . . . . . . 452
11.2.4 External Knowledge . . . . . . . . . . . . . . . 453
11.2.5 Quality of Knowledge . . . . . . . . . . . . . 455
11.2.6 Knowledge Integration . . . . . . . . . . . . 457
11.3 Knowledge Acquisition . . . . . . . . . . . . . . . . . . . . 458
11.3.1 Acquisition via Domain Experts . . . . 458
11.3.2 Acquisition through Machine
Learning . . . . . . . . . . . . . . . . . . . . . . . . . 459
11.3.3 Acquisition through Remote
Sensing and GPS . . . . . . . . . . . . . . . . . . 460
11.4 Knowledge Representation . . . . . . . . . . . . . . . . . 462
11.4.1 Semantic Network . . . . . . . . . . . . . . . . 462
11.4.2 Rule-Based Representation . . . . . . . . . 463
11.4.3 Frames . . . . . . . . . . . . . . . . . . . . . . . . . . 465
11.4.4 Blackboards . . . . . . . . . . . . . . . . . . . . . . 467
11.5 Evidential Reasoning . . . . . . . . . . . . . . . . . . . . . . 468
11.5.1 Mathematical Underpinning . . . . . . . . 468
11.5.2 Evidential Reasoning and Image
Classification . . . . . . . . . . . . . . . . . . . . . 471
11.5.3 Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . 472
11.6 Knowledge-Based Image Analysis . . . . . . . . . . . 473
11.6.1 Knowledge-Based Image
Classification . . . . . . . . . . . . . . . . . . . . . 474
11.6.2 Postclassification Filtering . . . . . . . . . . 478
11.6.3 A Case Study . . . . . . . . . . . . . . . . . . . . . 479
11.6.4 Postclassification Spatial Reasoning . . . 485
11.7 Critical Evaluation . . . . . . . . . . . . . . . . . . . . . . . . 487
11.7.1 Relative Performance . . . . . . . . . . . . . 488
11.7.2 Effectiveness of Spatial Knowledge . . . 489
11.7.3 Strengths . . . . . . . . . . . . . . . . . . . . . . . . 490
11.7.4 Limitations . . . . . . . . . . . . . . . . . . . . . . 491
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493
12 Classification Accuracy Assessment . . . . . . . . . . . . . . 497
12.1 Precision versus Accuracy . . . . . . . . . . . . . . . . . . 498
12.2 Inaccuracy of Classification Results . . . . . . . . . . 500
12.2.1 Image Misclassification . . . . . . . . . . . . 500
12.2.2 Boundary Inaccuracy . . . . . . . . . . . . . . 501
12.2.3 Inaccuracy of Reference Data . . . . . . . 502
12.2.4 Characteristics of Classifi cation
Inaccuracy . . . . . . . . . . . . . . . . . . . . . . . 503
12.3 Procedure of Accuracy Assessment . . . . . . . . . . 504
