Image Classification Flashcards
Goal of classification process?
A key goal of any classification process is simplification or a reduction in the complexity of a system into something that is meaningful to the observer
Classification Algorithms: Minimum Distance to Mean
Relies on the straight line distance from the class means to the unclassified pixel
- All of the pixels in the image are assigned to one of the specified classes
- Insensitive to different degrees of variation in the spectral response of data
Classification Algorithms: Parallelepiped
- Specifies a minimum and maximum range of values for each class
- Range results in a rectangular box known as a decision region
- The advantage is that a small number of classes can be specified and some of the image left unclassified
Classification Algorithms: Stepped Parallelepiped
Boundaries developed based on a stepped approach which allows us to create tighter “boxes” to define the classes.
Classification Algorithms: Maximum Likelihood Classifier
- Evaluates both variance and covariance of the category spectral response pattern
- Calculates the probability (statistical) of a pixel belonging to each class
Non - Parametric Classification: Spectral Mixture Analysis (SMA)
- one pixel can reflect more than one element or class
- a Spectral Mixture analysis decomposes a pixel into its proportions
Non - Parametric Classification: SAM - Spectral Angle Mapper
The SAM is a nonparametric classifier that uses the shape of a spectrum (or any other linear combination of attributes) as a distinguishing criterion.
Non - parametric Classifier: Support Vector Machine (SVM)
a form of supervised classification technique that classifies an unknown sample into a predetermined class.
- the data points are mapped with a projection that will maximize their separation