I have finished the image classification process in another software package but many papares recommend the ArcGIS package to process post-classification which means from which one land scape type has been changed to what.
How can I process post-classification in ArcGIS 9.3 to look at the matrix of change or "From-to" change?
The way to do it is to use the Tabulate Area tool:
Spatial Analyst Tools --> Zonal --> Tabulate Area
The output is the cross-tabulted areas between 2 rasters.
Give the first raster as the input raster or feature zone raster, the zone field is the land cover class field, the second raster is your second input raster.
The result will be in areas not in amount of cells, but to arrive to the number of cells, you just need to divide it by your raster resolution (e.g, if the raster is 1kmx1km, divide the output by the resoltion in meters: 1000x1000)
The vertical will be your first raster cell values (FROM), the horizontal your second raster cells values (TO).
You could try these old instructions. Similar to Tabulate Area in the previous post, the Combine tool gives you every combination of cell values but with the count. You can Pivot Table (or export table to use MS Excel or MS Access cross-tabulation if you don't have an ArcInfo license needed for the ArcGIS pivot tool) to create a matrix of the sum of the counts to calculate various statistics (consult a statistics text for the authoritative formulae).
ArcMap's "Tabulate Area" tool suggested by @Gago-Silva is good. However, its result is just the cross table. If you want the from-to map as well, then I recommend the use of the post-processing facilities of QGIS's Semi-Automatic Classification Plugin (SCP).
