From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.tex.context/69621 Path: news.gmane.org!not-for-mail From: Hans Hagen Newsgroups: gmane.comp.tex.context Subject: Re: CMYK colors not as expected Date: Wed, 29 Jun 2011 10:10:58 +0200 Message-ID: <4E0ADE12.4040104@wxs.nl> References: Reply-To: mailing list for ConTeXt users NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1309335089 9597 80.91.229.12 (29 Jun 2011 08:11:29 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 29 Jun 2011 08:11:29 +0000 (UTC) To: mailing list for ConTeXt users Original-X-From: ntg-context-bounces@ntg.nl Wed Jun 29 10:11:25 2011 Return-path: Envelope-to: gctc-ntg-context-518@m.gmane.org Original-Received: from balder.ntg.nl ([195.12.62.10]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Qbpro-0001iJ-Vy for gctc-ntg-context-518@m.gmane.org; Wed, 29 Jun 2011 10:11:25 +0200 Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 30A0BCAE37; Wed, 29 Jun 2011 10:11:22 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (balder.ntg.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id EPXUZn9gtgPI; Wed, 29 Jun 2011 10:11:19 +0200 (CEST) Original-Received: from balder.ntg.nl (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 366C3CAE30; Wed, 29 Jun 2011 10:11:19 +0200 (CEST) Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id D9FD0CAE30 for ; Wed, 29 Jun 2011 10:11:17 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (balder.ntg.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id POGFrCzpIPvq for ; Wed, 29 Jun 2011 10:11:15 +0200 (CEST) Original-Received: from filter3-til.mf.surf.net (filter3-til.mf.surf.net [194.171.167.219]) by balder.ntg.nl (Postfix) with ESMTP id C1095CAE0C for ; Wed, 29 Jun 2011 10:11:15 +0200 (CEST) Original-Received: from smtp.ziggozakelijk.nl (D57D1DA2.static.ziggozakelijk.nl [213.125.29.162]) by filter3-til.mf.surf.net (8.14.3/8.14.3/Debian-5+lenny1) with ESMTP id p5T8BE4B031225 for ; Wed, 29 Jun 2011 10:11:15 +0200 X-Default-Received-SPF: pass (skip=loggedin (res=PASS)) x-ip-name=10.100.1.100; Original-Received: from [10.100.1.100] (unverified [10.100.1.100]) by pragma-net.nl (SurgeMail 5.2a) with ESMTP id 6809-1713362 for multiple; Wed, 29 Jun 2011 10:11:08 +0200 User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.18) Gecko/20110616 Lightning/1.0b2 Thunderbird/3.1.11 ThunderBrowse/3.3.5 In-Reply-To: X-Authenticated-User: hagen@controller-9 X-Bayes-Prob: 0.0001 (Score 0, tokens from: @@RPTN) X-CanIt-Geo: ip=213.125.29.162; country=NL; region=11; city=Den Haag; latitude=52.0833; longitude=4.3000; http://maps.google.com/maps?q=52.0833,4.3000&z=6 X-CanItPRO-Stream: uu:ntg-context@ntg.nl (inherits from uu:default, base:default) X-Canit-Stats-ID: 0eF1Ibefy - a90cfd82f154 - 20110629 X-Scanned-By: CanIt (www . roaringpenguin . com) on 194.171.167.219 X-BeenThere: ntg-context@ntg.nl X-Mailman-Version: 2.1.12 Precedence: list List-Id: mailing list for ConTeXt users List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: ntg-context-bounces@ntg.nl Errors-To: ntg-context-bounces@ntg.nl Xref: news.gmane.org gmane.comp.tex.context:69621 Archived-At: On 28-6-2011 2:06, Hans van der Meer wrote: > I would be pleased to get some advice from "color-knowledgeable people" on the following matter. > > In TV-broadcasts there are usually two kinds of subtitles present: Teletext as characters and DVB as pixels. These can be extracted and rendered with Metapost. I have done this, but I am not very satisfied with the colors produced. On the television screen they look bright, when rendered in Metapost they are dull and muddy. The text is barely readable. > > As I am fairly sure I did extract the correct bits from the CLUT contained in the stream, I wonder if I am doing something not right at the Metapost side. In the datastream the values given are the most significant 6, 4, 4 and 2 bits of respectively Y, Cr, Cb, T. These are scaled to the values given to Metapost by dividing them by 255. > > In the zip one finds the program (ConTeXt MKIV) used for typesetting, an example pixel map with clut, and the output. I would be obliged to get some comments. As you're doing a lot of calculations, you can consider using bitmaps \starttext \startMPpage draw bitmapimage(2,2,"334455 667788 99aabb ccddee") scaled 3cm rotated 15 ; draw bitmapimage(2,2,"33 55 77 99") scaled 2cm rotated 30 ; draw bitmapimage(2,2,"0000ff00 ff00ff00 00ff0000 ffff0000") scaled 1cm rotated 45 ; \stopMPpage \stoptext ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com | www.pragma-pod.nl ----------------------------------------------------------------- ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : http://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___________________________________________________________________________________