Questions tagged [color]
Questions about the visual perceptual property deriving from the spectrum of light, usually expressed numerically according to a color model.
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What is the most physically accurate representation of color possible in computer graphics?
I am looking for theoretical and implemented models to represent color in software that strives for physical accuracy.
I know that "color only exists in the mind" and that it sort of does not make ...
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What is the purpose of this cube in color quantization?
So, I go to install GMIC for Gimp via the package manager and landed myself upon the demo program. I have discovered things such as Hough transform and color quantization. So, I get the number of ...
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Can I have lower color bit depth in sample buffer than target framebuffer?
I´m looking into uses of high amount of samples in multisampling. If I have an RGBA8 framebuffer and render to it using multisample with many samples, say 32, dithering on per-sample level should ...
CommunityBot
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What graphics techniques can be used to simulate a color nebula effect?
I've been playing around with more advanced graphics these days (beyond the basic 2D UI and image effects that the iOS platform offers), and I'm wanting to implement a visual effect similar to how iOS'...
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Matching an HSV color with a blended color
This is hard to explain but I am going to try, then I will explain it as pure mathematics.
Look at this image.
So basically this is a moving line, each frame a new segment is added and the previous ...
CommunityBot
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Preserving luminance
I am writing an application with multiple colored surfaces. I would like to preserve luminance, i.e. a blue surface would appear as bright as a green one, are there tools to help for this?
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Encode two R11G11B10F buffers into one using Y'CbCr?
We are trying to optimize Lighting in fillrate. Integrated graphics chips are very slow in memory access.
There are two Light Buffers: one for Diffuse and one for Specular. Both use format R11G11B10F....
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Confusion between usages of linear RGB and sRGB
Suppose you have generated an image using linear values for RGB channels. E.g. you linearly interpolated it when doing blending, etc.. When you're going to present this on the screen, should the ...
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OpenGL - Colours not working properly
I am using a single VBO to store vertices in the follow format:
v1X, v1Y, v1Z, v1R, v1G, v1B, v2A,
v2X, ...
Vertex positioning is fine, shapes show up where expected, however instead of using the ...
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How much precision (half, float, double, etc) is enough for a Color class?
While doing some reading on how real-time applications handle color under OpneGL, I noticed that some examples implemented Color as a collection of 4 floats, while ...
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How can you interpolate over an array of say 5 colors?
I have an array of color values. I have an interpolating parameter, t, which varies from 0 to ...
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Why does checkerboard pattern on a computer screen appear with a yellowish tint?
This question was originally asked on Physics, then moved to Cognitive Sciences.
Consider the following image:
You might want to display the image in a new page, in case it gets resized for mobile ...
CommunityBot
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Fading an object in add mode with correct color math
I have a scene rendered entirely with objects with additive blend mode. I have a value that is oscillating from 0, to 1. When it is 1 the object is supposed to be invisible, 0 should be entirely ...
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Is there a way to interpolate color across the line with only integer calculation ?`
Here is my function that does interpolation
...
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Why does the 1/r² term appear with point sources?
I'm currently reading some books on radiometry. They mention that radiance is constant along a ray. It doesn't change with distance.
However, I've seen some raytracer and they put the 1/r² factor when ...
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What is the effect of the BRDF denominator?
I was reading a paper on BRDF. I've come across this formula :
$$ f(\omega_i, \omega_o ) = \frac{FDG}{4(N.V)(N.L)}$$
The (N.L) term can be cancelled by the cosine term which appears in the rendering ...
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How to detect a screen in a photo
Is there a way to make a difference between a photo of an actual object and a photo of an object through a computer or smartphone screen.
For example: how can I detect that the second image is taken ...
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Spectral path tracing - image color/brightness incorrect
I implemented a spectral path tracing using physically base BRDF models such as Oren-Nayar,Specular Reflection and Transmission, Lambertian. All calculation in the path tracer uses standard illuminant ...
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What does "muted" mean in the context of color?
I want to extract colors from images like in Adobe Kuler. When I select colorful or muted corresponding colors are shown. But what is the definition for colorful or muted colors? What do the words "...
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Best technique to draw overlapping colored line segments that follow the same route
I'm not too versed in computer graphics so my question may be vague.
I'm given a sequence of GPS coordinates which I draw on an iOS map, and they define bus routes. Some of the bus routes happen to ...
CommunityBot
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Function to convert HSV angle to RYB angle
I'm trying to create a RYB color wheel with a smooth-looking gradient across the RYB spectrum. The angles of the HSV wheel are incorrect (yellow at 60deg instead of 120deg etc).
If I just do a few ...
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Javascript color extraction library
I have a small project that needs to extract the perceptually-salient colors of an image, in javascript. There are a few libraries out there (color-thief.js, vibrant.js). The trouble is, I'm finding ...
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Brightness and contrast VS Gamma, is it possible to identify the gamma "correction amount"?
Trichoplax question aroused my curiosity and the answers in this question also reminded me why I sometimes use different gamma "amounts" to enhance images.
Therefore, is it possible to determine the ...
CommunityBot
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Actual vs Perceived Brightness of RGB Colour
In this video from about 1:15, it is stated that if you have an RGB value of (0.5,0.5,0.5) it is only 22% as bright as (1,1,1) rather than the expected 50% as bright.
Does this mean that RGB is ...
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How to do a color separation with more than 3 primary colors
How would one do a color separation if there are more than 3 color primaries, or the primaries are nonstandard. In Standard CMYK conversion K is relatively easy conceptually to figure out. Its just a ...
CommunityBot
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Is colorized subpixel rendering possible?
Subpixel rendering is used most commonly to anti alias fonts. It works by leveraging the physical layout of the color components of a display to give geometry details to an image that are smaller than ...
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Are there common materials that aren't represented well by RGB?
In graphics we use RGB and other color spaces as an approximation to the full spectrum of light wavelengths. This evidently works pretty well in general, but are there any reasonably common objects/...
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How is an ICC profile embedded or built into an image?
If I were to analyze or change an ICC profile embedded in an image, how should I proceed?
I'd also be glad to understand how an "end-user" is able to create these with a tristimulus colorimeter or a ...
CommunityBot
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Finding a color perceptually similar to an image
I'm working on a program to use randomly-selected images as a desktop background. Now, not all images are the same shape as a computer monitor. One idea I had for dealing with this is to set a ...
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How can I detect edges between different colours of the same brightness?
I'm looking for an algorithm that can identify edges across which colour is changing sharply, rather than just finding changes in brightness.
Is this just a matter of using a different colour space ...
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What are the side effects of biasing brightness in continuous spectrum raytracing?
I want to model rays with a continuous range of frequencies so that I can get raytraced images with colour separation on refraction. I can model a light source with a specified frequency distribution ...
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