4 ms·
Roughly a third.
by simonblack 2y ago
Roughly a third.
- valine 2y agoWe don’t store color data in full precision usually. People aren’t sensitive to all colors equally, the less sensitive the eye is to a particular color the more efficiently you can store it. You can also typically discard high frequency data in your color channels. So not only are you not storing full precision data, you also don’t need to store roughly a third of the frequency bins. You can think of this like cropping the image but in the frequency domain. The data saving are identical to cropping the image but visually imperceptible.
- shagie 2y agoThis shows up in CCD sensors where you have two green pixels, one red, and one blue in a 2x2 square. You can see the sensitivity as part of the ppmtopgm program. ppmtopgm (https://netpbm.sourceforge.net/doc/ppmtopgm.html https://netpbm.sourceforge.net/doc/ppmtopgm.html) ppmtopgm reads a PPM as input and produces a PGM as output. The output is a "black and white" rendering of the original image, as in a black and white photograph. The quantization formula ppmtopgm uses is y = .299 r + .587 g + .114 b. Note the coefficient for blue is 0.114 and green is 0.587. This also has a spoof on Late Lament ( https://youtu.be/VNC54BKv3mc?t=109 https://youtu.be/VNC54BKv3mc?t=109 ) that gives me a chuckle... Cold-hearted orb that rules the night Removes the colors from our sight Red is gray, and yellow white But we decide which is right And which is a quantization error.
- pajko 2y agoThere are more formulas to be used, depending on the source material: https://en.wikipedia.org/wiki/Grayscale#Luma_coding_in_video_systems https://en.wikipedia.org/wiki/Grayscale#Luma_coding_in_video...