11
votes
Accepted
Why does checkerboard pattern on a computer screen appear with a yellowish tint?
Because your monitor is not properly calibrated.
On my screen at home the top and bottom parts have the same hue. At my office though, the top part tends to looks a bit yellow compared to the bottom ...
- 4,380
7
votes
Accepted
Why replicating the higher bits of RGB565 when converting to RGBA8888?
Without replicating the bits the LSBs will be 0, so for the maximum value of 0x1f (max for 5 bits) it would expand to 0xf8 when converted to 8 bit. What you want is 0xff so the range of 0x00->0x1f ...
- 2,312
7
votes
Why replicating the higher bits of RGB565 when converting to RGBA8888?
There's actually a reasonably good mathematical reason for doing bit replication:
First note that the n-bit string, $N$, actually represents the value $\frac{N}{2^n-1}$ and we want to produce the m-...
- 4,181
4
votes
Change particular color in an image
In order to replace a color with another color, you need some sort of distance metric between the colors and a function for calculating the blending based on that distance.
Finding a distance ...
- 3,401
4
votes
Accepted
What determines the color gamut of a display?
The physical imaging elements of your monitor define your gamut. So things like how bright the elements can be as well as the color spectra of the color elements define the gamut. But, thats quite the ...
- 8,397
2
votes
Color space of MERL BRDF database?
Was interested in this myself and did some digging, I was wondering if they where spectral, but it appears not (although some interesting work on spectral BRDF is here http://web.cs.wpi.edu/~emmanuel/...
- 139
2
votes
Pixel density / color channel depth ratio for dithered gradients
There has been quite some research into this using Barten contrast sensitivity function. It is the current formula behind the Dolby Perceptual Quantizer as featured in SMPTE 2084 and HDR10.
This, ...
- 318
2
votes
Change particular color in an image
Assuming you are looking to transform a particular component (r, g or b) of any color, this can be easily done by simple vector/matrix multiplication.
The introduction on this page (Chapter 6.1) - ...
- 131
2
votes
Accepted
Is there a way to resize an image without creating new colors in the output image?
A nearest-neighbor resize will do what you ask but I am not certain it will give you much smaller tiles.
It is quite likely that the tiles made from the original image are smaller simply because they ...
- 1,585
1
vote
YUV to HSV to RGB issues
Think about it this way. To calculate YCbCr of (1, 0, 0), you'll end up with Y = 0.299, Cb = -0.16873, Cr = 0.5. If you take the magnitude of the chroma channels (...
- 3,401
1
vote
Color space of MERL BRDF database?
Someone points me that this article describes the spectral response of the camera the MERL paper used, and even provides colour transform matrices at the end. Unfortunately, using those transforms ...
- 1,266
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