So I really shouldn’t be doing this right now, and I should be intense studying for my exams, but I’m about to go insane from studying and figure this might be a good release. I got fed up with trying to understand particles and statistical mechanics and what do I do? I decide to read up on my latest guilty pleasure in the world of science, and that would be colour and colour theory. It sounds kind of mundane at first (colour naming is a big part of these researcher’s jobs, they even have colour thesaurus!) but it just doesn’t make sense when you throw a bunch of post-docs with computer science and physics degrees into colour naming. Upon further reading, I’ve discovered that there’s actually a plethora of complicated physics involved unbeknownst to the world. So what better do I have to do at 4 am in the morning than to give a job profile of the lovely underrepresented colour theorists.
Research is colour science currently is two-fold. First and foremost is skirting close to God himself: healing the blind by creating synthetic eyeballs. The relationship between how the eye sees colour and how the brain processes it is still basically a complete mystery to us mere mortals. We understand how the eye functions itself, and we can transmit the information to the brain, but the processing of the data in the brain remains a very vague field. If we can understand this, we can create much more efficient imaging processing algorithms, used in places like CT Scans and MRI machines. The second big research field is perfect imaging capture. In many cases, pictures taken with a regular digital camera turns out completely misrepresentative of how the scene actually is. Each imaging input and output region filters the picture to less and less of what it should be. In the example of the camera, the digital camera first captures the light in a slightly distorted manner. Then comes the problem of displaying it in a combination of red, green, and blue pixels that attempt to describe the already-distorted picture. The only true non-distorted filter is the one through our own eyes, which only through understanding how the brain works with processing the information for what image we truly see. Applications to this minimization of distortion include virtual archives of museum artifacts, and more detailed medical imaging.
Colour science actually gets pretty involved. I would just like to note the difference when the filters I was talking about before are applied. First picture is a comparison between the RGB (red-green-blue) system to the CMYK (cyan-magenta-yellow-black) system. This is a typical conversion between the display on a monitor over the actual printed image.

The next picture is a display of the colour systems. It shows a graph (with no axis — what blasphemous science is this?!?) with wavelength as the horizontal axis and the intensity/amplitude as the vertical. As expected, it is a nice distribution of colours and progresses through the spectrum of the rainbow. Left of this graph would be ultraviolet light, and right of it would be infrared, both not visible to the human eye and not relevant. The full distribution of light is what our eyes can detect, and the shapes enclosing a certain area describes the limitation of what each imaging technology can display.

To improve the colour representation this is where the math comes in. Surprisingly, it involves calculus, and even more surprising is that it involves a lot of linear algebra. Like all of the abstract stuff like vector spaces and stuff. I mean, who even does that anymore? In any case, it turns out you can define a vector space of colour, a colour space, that describes all the colours with the 3 fundamental colour vectors, red, green, and blue. Alternatively, you can describe all the colours in greater precision and crispness with vectors of only hue, saturation, and lightness. And whaddya know, to get from one colour space to the other, we apply a coordinate transformation! If you’re not getting much of this, it’s okay. I don’t really either. Man, I should have paid attention in linear algebra.
Turns out, with these coordinate spaces, you can define coordinate systems and apply calculus to it to find the change in hue/saturation/brightness in a certain direction in an image, and then make modifications to that function calculated to adjust its image clarity. Below is just a generic coordinate system (cylindrical coordinates!) of HSL.
That’s all from here. I think, just maybe, it’s time for me to go to bed.

