Path: csiph.com!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: John Ames Newsgroups: comp.sys.tandy Subject: Re: Anyone left? Date: Fri, 18 Jul 2025 12:06:18 -0700 Organization: A noiseless patient Spider Lines: 149 Message-ID: <20250718120618.000024cc@gmail.com> References: <760404673@darkrealms.ca> <20250717081932.000030ce@gmail.com> <20250717090937.0000649c@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Injection-Date: Fri, 18 Jul 2025 21:06:23 +0200 (CEST) Injection-Info: dont-email.me; posting-host="a9878a3c792ac205cadd3e7661c1c866"; logging-data="2305670"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+HphU/OHCXIBAfKxOu5mVwj+yi4F2J7Sg=" Cancel-Lock: sha1:EPEMz+vK7Y1ozX2NDDCmkv07Tmo= X-Newsreader: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Xref: csiph.com comp.sys.tandy:777 On Thu, 17 Jul 2025 09:09:37 -0700 John Ames wrote: > > (there are, IIRC, 136 unique combinations of 16-color pixel pairs, > > (Though, thinking about it, there are probably fewer than 136 > "average" colors that these'd work out to. Should look into this > sometime.) Well, I got curious and looked into this a bit. Using the semi-canonical RGBI reference colors: (element value) = (color bit * 170) + (intensity bit * 85) with the special case for color 6 (dark yellow/brown) where green intensity is halved, and the color-averaging function: (average) = sqrt(((a * a) + (b * b)) / 2) I identified 122 unique "composite" colors. For cases where multiple color pairs yield the same "composite" RGB value, the lowest-contrast pairing has been preferred, and the subjectively brighter color is kept in the left pixel to minimize luma "noise." The table, sorted by approximate luminance: Byte RGB 0x00 #000000 0x10 #000078 0x11 #0000AA 0x40 #780000 0x41 #780078 0x44 #AA0000 0x51 #7800AA 0x80 #3C3C3C 0x54 #AA0078 0x81 #3C3C86 0x55 #AA00AA 0x20 #007800 0x60 #783C00 0x90 #3C3CB4 0x91 #3C3CD9 0x48 #863C3C 0x21 #007878 0x61 #783C78 0x88 #555555 0x64 #AA3C00 0x31 #0078AA 0x58 #863C86 0x49 #863CB4 0xC0 #B43C3C 0x68 #86553C 0x98 #5555BE 0x65 #AA3C78 0x22 #00AA00 0x59 #863CD9 0x66 #AA5500 0x28 #3C863C 0xC1 #B43C86 0x99 #5555FF 0x24 #787800 0xC4 #D93C3C 0xD0 #B43CB4 0x69 #8655B4 0x38 #3C8686 0x32 #00AA78 0xD1 #B43CD9 0x26 #788600 0xC5 #D93C86 0xC8 #BE5555 0x29 #3C86B4 0x33 #00AAAA 0x25 #787878 0xD4 #D93CB4 0x39 #3C86D9 0xC6 #D9553C 0xD5 #D93CD9 0x35 #7878AA 0x36 #788678 0xC9 #BE55BE 0xA0 #3CB43C 0x78 #868686 0x74 #AA7878 0xD6 #D955B4 0xD9 #BE55FF 0xCC #FF5555 0xA1 #3CB486 0xC2 #B4863C 0x75 #AA78AA 0x76 #AA8678 0x79 #8686D9 0xB0 #3CB4B4 0xA8 #55BE55 0xC3 #B48686 0xDC #FF55BE 0xB1 #3CB4D9 0x72 #78AA78 0xA2 #3CD93C 0xA4 #86B43C 0xD2 #B486B4 0x73 #78AAAA 0xDD #FF55FF 0xD3 #B486D9 0xA6 #86BE3C 0xA9 #55BEBE 0x7C #D98686 0xA3 #3CD986 0xA5 #86B486 0xB2 #3CD9B4 0xB9 #55BEFF 0xB4 #86B4B4 0xE0 #B4B43C 0x7D #D986D9 0x77 #AAAAAA 0xB3 #3CD9D9 0xB5 #86B4D9 0xB6 #86BEB4 0xE1 #B4B486 0xE4 #D9B43C 0xAC #BEBE55 0xF0 #B4B4B4 0xA7 #86D986 0xE6 #D9BE3C 0xF1 #B4B4D9 0xAA #55FF55 0xE5 #D9B486 0xE2 #B4D93C 0xAD #BEBEBE 0xF4 #D9B4B4 0xB7 #86D9D9 0xF5 #D9B4D9 0xE3 #B4D986 0xBA #55FFBE 0xF6 #D9BEB4 0xBD #BEBEFF 0xEC #FFBE55 0xF2 #B4D9B4 0xBB #55FFFF 0xF3 #B4D9D9 0xE7 #D9D986 0xED #FFBEBE 0xEA #BEFF55 0xFD #FFBEFF 0xF7 #D9D9D9 0xEB #BEFFBE 0xFB #BEFFFF 0xEE #FFFF55 0xFE #FFFFBE 0xFF #FFFFFF