I have Classified two Landsat images for Post-Classification Comparison and Cross-tabulated the data to detect change.
How do I generate a change map from this data using ArcGIS 10.2.2?
assuming they are now single band rasters containing an integer classification scheme, you can use the combine tool
Combine—Help | ArcGIS for Desktop
Combine will produce a new classification scheme showing the unique combinations of the input classes as per the figure in the help topic. You will have to put some context to this scheme since their numerical/class values will change. As a companion to this, you could just produce a binary scheme showing the extent to which the classifications remained the same. This can easily be accomplished using Con whereby class X on map A = class X on map B is assigned 1 and everything else to 0. You can also do this by subtracting and reclassification. Once you have produce the binary map, you could focus on the areas where the classifications differed.
So there are many options depending on what it is you wish to reveal given the time differences in the classifications
Retrieving data ...