Posted By
Gaia
on 2016-12-12
16:24:21
|  Re: Pepto palette for TED?
Delay line, scanlines, chroma subsampling, hanover bars are all emulated by most emulators by now.
YAPE has been having a "pepto" inspired palette since 2001 (more or less since the original article was published I believe). Actually, we had the luxury that the original hues were published in the preliminary TED documentation. Unfortunately they have been proven to be off by quite some margin (hence "preliminary" I guess). I still kept it in YAPE for the kicks of it (and who knows there might be prototypes with a 7360R1 around having those actual hues? The NTSC hues look a lot closer for example).
These are those original (preliminary) hues starting from red (in degrees, converted to PAL):
103, 283, 53, 241, 347, 167, 129, 148, 195, 83, 265, 323, 5 (23), 213
Maybe #14 is changed since it was so much off I am not sure anymore (it's easy to check though).
These are the hues extracted from pepto's website:
101.25, 281.25, 56.25, 236.25, 348.75, 168.75, 123.75, 146.25, 191.25, 78.75, 258.75, 326.25, 11.25, 213.75
By the looks of it I would say the pepto TED palette is a nice 'desk research' attempt at conceptualizing the TED colours... it is placing the hues on the circle in an idealistic "equidistant" pattern. Some colours seem way off to me just by comparing it to my TV card's output (like pink, for example). Could be that this is what we could find on the actual silicon but gets distorted by the myriads of analogue circuitry and the TV cards.
The thing is, the TED developers have been clearly thinking in North American NTSC terms, so those weird hues ending with 3's are actually nice round NTSC hues rotated by 33 degrees (as is required). So if there is a nice "round" hue table than it almost certainly in NTSC and would look like those in the original TED docs:
70, 250, 20, 200, etc.
These are the hues from plus4emu:
103.0f, 283.0f, 53.0f, 240.0f, 347.0f, 167.0f, 130.0f, 148.0f, 195.0f, 83.0f, 265.0f, 323.0f, 3.0f, 213.0f
Finally the hues from the latest YAPE branch (PAL palette, no CRT emulation):
105, 280, 53, 240, 345, 167, 135, 150, 190, 89, 270, 320, 1, 210
These are the ones that I have calibrated with one of my plus/4's using a TV card. Admittedly it's probably not quite like a 1084s but then again there is so much analogue stuff going on in there that it is as good as anyone's guess. I have been struggling a bit with the clipping of the Y'UV values and especially how these should be converted to YCbRB (which is a format using chroma subsampling but is not what happens in a real CRT). Anyway, the ultimate solution will be feeding the YUV colour data to some pixel shader which can do all the fancy CRT magic stuff and convert everything to RGB). Have a look at here:
http://filthypants.blogspot.hu/2011/05/more-emulator-pixel-shaders-crt-updated.html
You see colours are very "subjective", our eyes can be very different and generally most people are a lot less perceptive to changes in hue than changes in luma. So there won't ever be a palette that everybody'll like  But You, as an artist, are probably a lot more affluent
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