Would Halide[0] be what he's looking for? It's a DSL, sure, but one that is embedded in C++, so you can at least program your whole pipeline in place, giving you a good grasp of the flow of the program(s).
Anyway, as far as I know it is limited to 2D raster images so far, yes. Since it's part research language with some very interesting features I do hope that it gets extended to more general cases, and at least make it easier to work with 3D use cases (image volumes and such) too.