Classification of a raster file is the process of reassigning a value, a range of values, or a list of values in a raster to new output values. Classification is an important part of data analysis. Some of the reasons you may want to classify data are:
- Exclude cells with null values.
- Update cell values in response to a change in the classification scheme.
- Replace one set of values with an associated set of values.
Classification is done by reclassifying one value at a time or groups of values at specified intervals. Classification changes the values in a raster. For example, while performing wildlife habitat analysis, the values of a raster representing each different type of land use, need to be changed to a specified range, to make the land use type relevant to a particular wildlife species type. In this way, a forest land area is reclassed to a value different to that of a high density industrial land area.
The Classify tool enables you to reclass values in a classified grid to make the data more suitable for your analysis. When you reclass a grid, you generate a new grid. You can re-class a classified grid into a classified raster.