Foveon is apparently "more of YUV", because it's not yet possible to band-stop just the desired wavelength range for each layers and let others pass. Instead th

Foveon is apparently "more of YUV", because it's not yet possible to band-stop just the desired wavelength range for each layers and let others pass. Instead the three layers gets RGB, RG and R channels respectively, and the camera computes the delta. The "Quattro" generation Foveon used 2x2 subpixels for the top layer. My impression then was it was a last-ditch effort to mitigate poor sensitivity, but it's interesting how it was arguably an only analog convolutional network processor in a consumer product, from a different perspective.