3 research outputs found

    Continuous Iterative Guided Spectral Class Rejection Classiļ¬cation Algorithm: Part 1

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    This paper outlines the changes necessary to convert the iterative guided spectral class rejection (IGSCR) classification algorithm to a soft classification algorithm. IGSCR uses a hypothesis test to select clusters to use in classification and iteratively reļ¬nes clusters not yet selected for classification. Both steps assume that cluster and class memberships are crisp (either zero or one). In order to make soft cluster and class assignments (between zero and one), a new hypothesis test and iterative reļ¬nement technique are introduced that are suitable for soft clusters. The new hypothesis test, called the (class) association signiļ¬cance test, is based on the normal distribution, and a proof is supplied to show that the assumption of normality is reasonable. Soft clusters are iteratively reļ¬ned by creating new clusters using information contained in a targeted soft cluster. Soft cluster evaluation and reļ¬nement can then be combined to form a soft classification algorithm, continuous iterative guided spectral class rejection (CIGSCR)

    Enrichment Procedures for Soft Clusters: A Statistical Test and its Applications

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    Clusters, typically mined by modeling locality of attribute spaces, are often evaluated for their ability to demonstrate ā€˜enrichmentā€™ of categorical features. A cluster enrichment procedure evaluates the membership of a cluster for significant representation in pre-defined categories of interest. While classical enrichment procedures assume a hard clustering deļ¬nition, in this paper we introduce a new statistical test that computes enrichments for soft clusters. We demonstrate an application of this test in reļ¬ning and evaluating soft clusters for classification of remotely sensed images

    Automatic template-guided classification of remnant trees

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    Spectral features within satellite images change so frequently and unpredictably that spectral definitions of land cover are often only accurate for a single image. Consequently, land-cover maps are expensive, because the superior pattern recognition skills of human analysts are required to manually tune spectral definitions of land cover to individual images. To reduce mapping costs, this study developed the Template-Guided Classification (TGC) algorithm, which classifies land cover automatically by reusing class information embedded in freely available large-area land-cover maps. TGC was applied to map remnant forest within six 10-m resolution SPOT images of the Vermilion River watershed in Alberta, Canada. Although the accuracy of the resulting forest maps was low (58% forest user's accuracy and 67% forest producer's accuracy), there were 25% and 8% fewer errors of omission and commission than the original maps, respectively. This improvement would be very useful if it could be obtained automatically over large-areas
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