Images are just data in tables. You can process them using point-and-click user interfaces like the Transform pane (brain fade... I forgot to mention that in my prior post) or the Join dialog, or you can manipulate that data using SQL or scripts.
Many geoprocessing jobs boil down to basic database operations like joins, so SQL works very well, and can be way more orderly than ad hoc scripting in languages like Python or C#, or "raster calculators" that don't have full database power on tap when you want it. Manifold SQL is parallel as well, so what you write in SQL will be automatically parallelized both CPU parallelized and GPU parallelized, something that's useful when working with rasters.
Those who prefer a more typical GIS approach can always use the scripting language of their choice, since the many functions that work with tiles/rasters/images can be called from scripts as well.
About that Transform pane... when you look into topics like Transform - Tiles: Compose, there are very many capabilities that unfold from that. For example, all those pull-down boxes where you can pick channels from the image are not limited to being only one of the channels as is. Each one of them can be an expression that's as arbitrarily complex as you like. You could create TPI displays by putting an expression into one of those option boxes.