# Tag Info

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Red is the gray scale channel (black/white). To generate a gray scale image copy the Red channel to the Green and Blue channels, set alpha to one and a gray scale image will result. Of course that single channel can be used for many other purposes besides just gray scale image data. It can represent noise, a lookup table (LUT). The list is long and mighty.

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In Computer Graphics, we most often represent colours using a red, green, and blue value, also known as RGB. And, in Computer Graphics, we generally represent those red, green, and blue values with numbers ranging from 0 to 1. A value of 0.0 means 0% brightness or pure black. A value of 1.0 means 100% brightness or pure white. Now, you might think that ...

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First, you have to consider what having an alpha value less than one means. You can consider an RGBA colour like $(1,0,0,0.5)$ as "a red object that is 50% transparent"; but an equivalent way, which I think is more useful for reasoning about, is to think of it as "an opaque red object that covers half of the pixel". Then a pixel with an ...

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That looks a lot like it’s based on the straight skeleton of some outline shapes drawn on the image. You can see similar structures in the middle one of these diagrams from a research page by Stefan Huber, one of the researchers who’s published a lot of work on straight skeletons:

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In general this is caused by HDR tone mapping. Tonemap curves typically decrease saturation as the input light gets brighter, so that very bright lights are rendered closer to white on the display. If bloom is rendered in HDR (prior to tonemapping) then the bloom around the light can still be highly saturated since it is of a lower intensity than the light ...

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Maybe. HDR monitors are typically going to be some approximation of the DCI-P3 color space, while Adobe's wide-color rendering is the Adobe RGB color space. The two are similar but not quite the same; in particular, Adobe RGB extends a bit further into the green-cyan range than DCI-P3 does: That said, these are only idealized color spaces, and the gamut of ...

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Removing hue and saturation ("desaturating") leads to a grayscale image with the same luminance as the original colors, for instance: (source: my own photo) It is not possible to remove hue alone without removing saturation, as any saturated color must be saturated in some direction (hue). Nor is it possible to "split" the image into HSV ...

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The actual color of a pixel, outputted on a monitor, does not linearly depend on the applied voltage signal for that pixel. For CRT monitors, the actual color is approximately proportional to the applied voltage raised to the power of a so-called gamma value, which depends on the monitor. This gamma value typically lies between 2.2 and 2.5 for CRT monitors. (...

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The effect is called chromatic aberration; the way it’s usually done in games, and what’s being done there, is by reading the red / green / blue channels of an image at different offset positions. As with your other question (you’re looking to get into the NFT market, I’m guessing?), there are most likely plugins for After Effects that will let you create ...

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This effect is called Color Cycling (or Palette Shifting). Mark Ferrari has a great GDC talk where he demonstrates and explains the entire technique. You can view a bunch of his artwork based on this technique here. The main idea is that each pixel is painted not with a single color, but as values of a look-up table to a palette of colors. The entire image ...

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What you're looking for is called tone mapping, which is the process of mapping from HDR color values generated by a physically based renderer, to LDR color values suitable for display on a screen. It also incorporates changes in saturation, such as desaturating the color when the values get very bright. You will likely also need exposure compensation prior ...

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Well, its not as defined as you would like it to be. There is no definitive answers to this. It really depends on what you model with alpha and RGB values. Generally we can model one of 2 things with alpha. We can model transparency or we can model coverage. Because coverage is a bit pesky to deal with most often we just model the aggreagate of coverage and ...

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The video is over simplifying a problem that has a long history and is far more complex then just "how a camera captures images". Especially today when we have cameras that can capture flat out amazing amounts of data. If someone shows you a color wheel, that never changes, then starts changing the brightness of the light illuminating that color ...

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If by adding two colour values with alpha you mean to combine them for the purposes of blending then here's the answer you need. I'll show the full derivation too. Feel free to scroll down to the TL;DR indicator if you're in a hurry. Luminance-alpha formats Let’s simplify this by considering an image using the monochrome luminance-alpha format. Pixels in ...

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The book distinguishes a spectral power distribution from a spectral response curve because they are not the same, they are adjoint. The thing about adjoints that makes them a little tricky to wrap your head around is that they typically have the same representation in software, but keeping them distinct is extremely important in computer graphics. Another ...

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Welcome to the world of 8-bit graphics! Other answers here are excellent, and most of what you need to know is described well on Wikipedia but let me take you on a human-friendly journey of understanding that I wish someone would have taken me on when I was younger. The first realization that you need to make is that a pixel with RGB values 128, 128, 128 ...

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Gamma correction originated as a way of correcting the output of a CRT to be a better fit for the human visual system. Modern monitors don't need to do it, but, they followed the CRT and there were millions of CRT's that all had gamma correction and most signals already had gamma correction in them. Today we have a chicken and egg problem...but reversed. ...

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