It's not really grayscale. The output of an image sensor integrated circuit is a series of voltages read one after the other, that could be from –0.3 to +18 volts for example, in an order specific to the sensor's red, green and blue "pixels" arrangement. The native picture (fig 1) is the result of converting a sensor's output voltage to a series of values from black (let's say -0.3 volts for example) up to white (let's say +18 volts for example) while ignoring if they are from a red, a green or a blue image sensor "pixel".
The various "raw" camera image formats kind of work like this, they include the voltages converted to some numerical range and what each "pixels" represents for a specific camera sensor setup.
Well for most, the next steps are probably towards removing the highly deterministic and discrete characteristics of current approaches (we certainly don't think in lock steps). Those have no measures. Even the creative aspect is undermined by those characteristics.
The various "raw" camera image formats kind of work like this, they include the voltages converted to some numerical range and what each "pixels" represents for a specific camera sensor setup.