The raw file contains light level recordings affine to the real scene illumination. (The black point is raised, which is why it's affine, not linear). (Assuming

The raw file contains light level recordings affine to the real scene illumination. (The black point is raised, which is why it's affine, not linear). (Assuming no bright pixels are clipped). Each rgb channel is a filtered spectrum. But note that the color filters are essentially arbitrary, and only roughly correspond to the color filters of your eyes or your screen. Also note that some cameras pre-process even raw data, for example with vignetting correction or noise reduction. Some phones even do image fusion and color correction, then re-rawify the data by mosaicing and linearization.