From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/74280 Path: news.gmane.org!not-for-mail From: Greg Troxel Newsgroups: gmane.emacs.gnus.general Subject: Re: Colour manipulation Date: Tue, 23 Nov 2010 20:09:15 -0500 Message-ID: References: <87pquvldcs.fsf@lifelogs.com> <87oc9yp21w.fsf@lifelogs.com> <87lj4pmgu7.fsf@keller.adm.naquadah.org> <87oc9ihjbk.fsf@keller.adm.naquadah.org> <8739quh5gk.fsf@keller.adm.naquadah.org> <87zkt1b0nv.fsf@lifelogs.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" X-Trace: dough.gmane.org 1290561034 29070 80.91.229.12 (24 Nov 2010 01:10:34 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 24 Nov 2010 01:10:34 +0000 (UTC) Cc: Ted Zlatanov , ding@gnus.org To: Julien Danjou Original-X-From: ding-owner+M22645@lists.math.uh.edu Wed Nov 24 02:10:29 2010 Return-path: Envelope-to: ding-account@gmane.org Original-Received: from util0.math.uh.edu ([129.7.128.18]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1PL3sT-0007qt-Hy for ding-account@gmane.org; Wed, 24 Nov 2010 02:10:29 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.math.uh.edu) by util0.math.uh.edu with smtp (Exim 4.63) (envelope-from ) id 1PL3rr-00049u-Gj; Tue, 23 Nov 2010 19:09:51 -0600 Original-Received: from mx2.math.uh.edu ([129.7.128.33]) by util0.math.uh.edu with esmtps (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from ) id 1PL3rq-00049j-7h for ding@lists.math.uh.edu; Tue, 23 Nov 2010 19:09:50 -0600 Original-Received: from quimby.gnus.org ([80.91.231.51]) by mx2.math.uh.edu with esmtp (Exim 4.72) (envelope-from ) id 1PL3rl-0006Qv-6Q for ding@lists.math.uh.edu; Tue, 23 Nov 2010 19:09:50 -0600 Original-Received: from linuxpal.mit.edu ([18.62.1.14]) by quimby.gnus.org with esmtp (Exim 3.36 #1 (Debian)) id 1PL3rk-0004X6-00 for ; Wed, 24 Nov 2010 02:09:44 +0100 Original-Received: by linuxpal.mit.edu (Postfix, from userid 9545) id E56E718092; Tue, 23 Nov 2010 20:09:42 -0500 (EST) X-Hashcash: 1:20:101124:tzz@lifelogs.com::okjNEhXvSEUQhbkv:00GBc X-Hashcash: 1:20:101124:julien@danjou.info::B2zCFjzI8wkTkUvp:00000000000000000000000000000000000000000000wIL X-Hashcash: 1:20:101124:ding@gnus.org::B2zCFjzI8wkTkUvp:00006ohd In-Reply-To: (Julien Danjou's message of "Tue, 23 Nov 2010 10:10:51 +0100") User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.2 (berkeley-unix) X-Spam-Score: -4.9 (----) List-ID: Precedence: bulk Xref: news.gmane.org gmane.emacs.gnus.general:74280 Archived-At: --=-=-= Content-Type: text/plain Julien Danjou writes: > Any hint appreciated, while I read the Wikipedia page. IIRC there are multiple forms, some of which are defects in cone types and some in the later signal processing. The approach I'd try is to have a variable that can be set to various tokens to indicate them, and do some sort of folding of colors according to the particular problem before doing the distance-in-color-space calculations. I can no longer remember where I read this, but in some color theory reading there was a credible claim that there's a neural coding to luminance and red/green and yellow/blue and that some colorblindness is a neural problem in those pathways rather then a cone defect. See http://www.handprint.com/HP/WCL/color2.html and search for "In 1949 D.B. Judd specified". --=-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (NetBSD) iEUEARECAAYFAkzsZcUACgkQH9p66AmO1g5wJgCcDUicIhTs4iA+3r6itvGDtlmM gNQAmO2HSpRjQjes8L9mv8CcA3U3jN4= =e8xX -----END PGP SIGNATURE----- --=-=-=--