Path: csiph.com!usenet.pasdenom.info!news.albasani.net!news.swapon.de!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Ingo Thies Newsgroups: comp.graphics.apps.gnuplot Subject: Re: Extending plot types - adding a CIE 1931 type diagram Date: Thu, 08 Aug 2013 10:30:47 +0200 Lines: 23 Message-ID: References: <44f7bc66-d250-4545-8177-918325babe8d@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: individual.net SHGbk+9s6ic1UT90wKWTPAMqVcaNxJizenPIZcy4HTXz4bPHsz Cancel-Lock: sha1:oqoR0BRngiRdtPA+BG3p5fxtTm8= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130623 Thunderbird/17.0.7 In-Reply-To: <44f7bc66-d250-4545-8177-918325babe8d@googlegroups.com> Xref: csiph.com comp.graphics.apps.gnuplot:1954 Hi, On 07.08.2013 22:24, hvezdny.cestovatel@gmail.com wrote: > So the task would be: > 1. generate the background color image with the right coordinates, so that > 2. plot points and curves into that plot as usual, taking advance of the coordinate system of the CIE x-y diagram If it is merely plotting over a background image it is already possible, as Ethan said. Or do you also intend some RGB to x-y(-Y) or even spectrum to x-y(-Y) conversion? This would require to include the RGB to XYZ matrices and/or the CIE colour matching functions. Another question would be whether it should be CIE 1931 2-deg standard observer only or also include the CIE 1964 10-deg standard observer. CIE 1931 seems to be outdated although it is still used for the definition of sRGB (the differences in the image would be small anyway). Best wishes, Ingo