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Digital image processing - image classification

Q: What is supervised classification ?

the image analyse 'supervises' the pixel categorization process by specifying, to the computer alogorithm, numerical descriptors of the various land cover types present in a scene. 2 steps involves a training step followed by a classification step.

5 important questions on Digital image processing - image classification

What are spatial classifiers

they consider aspects as image texture, pixel proximity, feature size, shape, directionality, repetition and context.

What is temporal pattern recognition?

uses time as an aid in feature identification. in agricultural crop surveys, for example distint spectral and spatial changes during a growing season can permis discrimation on multidate imagera that would be impossible given any single date.

What is supervised classification ?

the image analyse "supervises" the pixel categorization process by specifying, to the computer alogorithm, numerical descriptors of the various land cover types present in a scene.
2 steps involves a training step followed by a classification step.

What is unsupervised classification?

the image data are first classified by aggregating them into the natural spectral groupings or clusters present in the scene.

What are the three basic steps in typical supervised classification ?

1. training stage ->representative training areas
2. classification stage -> each pixel in the image data set is categorized into the land cover class it most closely resembles.
3.output stage -> three typical forms of output products are thematic maps, tables of full scene or subscene area statistics for the various land cover classes and digital data files amenable to inclusief in a GIS.

The question on the page originate from the summary of the following study material:

An introduction to geographical information systems | 9780273722595 | Ian Heywood, et al

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