Remember all those old video graphics modes you used to get in the late eighties? You have to be a certain age to remember the frisson of excitement when you realised that your next computer could display sixteen colours instead of four
Video was out of the question. That would have to wait for the end of the decade and Quicktime: and that was only on the Mac.
So it's amusing and sobering at the same time to see real video reworked to run at these ancient resolutions, that are so low, it's hard to know how to relate them to modern resolutions. You can learn from this, though.
Notice that the main technique to display more colours than the technology was capable of natively is Dithering. What this does, essentially, is add noise to an image to add a little unpredictability, and what this unpredictability does is fool us - in a rather noisy way - that we're not looking at the harsh digital contours that you normally get when you've only got a few colours. And it works in space as well as time: it works inside an individual frame and from frame-to-frame on the time axis.
Dithering is a very useful process. If you add a little bit of noise to an 8 bit image, it can look almost as good as a 10 bit one. So it's very fortunate that most camera sensors make a bit of noise themselves, because, sometimes, it can actually make the pictures look better!
Unfortunately it can also make them look worse, as compression codecs struggle to deal with the randomness that noise introduces - but you can't have everything!
Enjoy the video on the next page.
Warning - there is powerful strobing and flashing in some of these clips.
Details from YouTube:
Video by JendaLinda
This is an experiment, how does video look in modes of old graphics cards. I have written my own converters and players. Best viewed in 480p.
Video is playing in these modes:
CGA mode - palette 1 (black, cyan, magenta, white), Floyd-Steinberg dithering
EGA mode - default palette (RGBI), Floyd-Steinberg dithering
VGA mode - 6 bits per pixel, all possible EGA colours, Floyd-Steinberg dithering
VGA mode - 8 bits per pixel custom palette (3-3-2 bit RGB), Floyd-Steinberg dithering
Text mode - 50 lines, one pixel per character, 300 colour shades using dithering characters
Text mode - 25 lines, one pixel per character, 300 colour shades using dithering characters
Text mode - 50 lines - two pixels per character using block characters, no dithering
Text mode - 25 lines - two pixels per character using block characters, no dithering
Text mode - 25 lines, monochrome, 5 shades of gray using dithering characters
Tags: Technology
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