Symbols for Legacy Computing (Range: 1FB00–1FBFF) would be a helpful block to look at as a possible optional even-higher-fidelity mode. Has all kinds of slopes

Symbols for Legacy Computing (Range: 1FB00–1FBFF) would be a helpful block to look at as a possible optional even-higher-fidelity mode. Has all kinds of slopes that you could better approximate edges with. You could probably solve for it efficiently by computing a small Histogram of Oriented Gradients block, say 3x3, and use that as a hashmap key. Or Sobel filters might be even easier.