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Nonparametric and Probabilistic Classification of Agricultural Crops Using Multitemporal Images Smögen Workshop, 21-25 August 2006. Jun Yu & Bo Ranneby Centre of Biostochastics The Swedish University of Agricultural Sciences Umeå, Sweden. Input Data. Field Data
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Nonparametric and Probabilistic Classification of Agricultural Crops Using Multitemporal ImagesSmögen Workshop, 21-25 August 2006 Jun Yu & Bo Ranneby Centre of Biostochastics The Swedish University of Agricultural Sciences Umeå, Sweden
Input Data • Field Data • Block database (marginal part as ground truth) • Block database (for evaluation) • Satellite Images
Crops 25 classes: Autumn-sown cereals Spring-sown cereals Spring-sown oil seed crops Potatoes …… Grass land on arable land (for hay or silage) Energy forest (salix) Wood land on pasture ……
Methodology • Define the target function (in this case, probabilities of correct classification) • Denoise the images • Remove outliers from reference data • Calculate the information values in the components in the feature vector (e.g. different bands) • Determine a proper metric • Determine prototypes for the classes • Run a nonparametric classification so that the target function is maximized • Declare the quality of classification result by using probability matrices
Classification test site 1 5 scenes 1 scene
Classification test site 2 1 scene 5 scenes
Probability Matrices 5 scenes 1 scene
Probability Matrices at level 1 5 scenes 1 scene Level 1: C1 – arable land; C2 – pasture and meadows
More quality … • Calculate probabilities for classes at pixel level • Calculate entropy for each pixel
Pixelwise probability per class, and entropy – test site 1 Entropy value
Pixelwise probability per class, and entropy – test site 2 Entropy value