From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Tomas Hlavaty Newsgroups: gmane.emacs.devel Subject: Re: Emacs Survey: Toolbars Date: Fri, 25 Dec 2020 19:06:37 +0100 Message-ID: <87h7o9yd3m.fsf@logand.com> References: <87o8iv3ac3.fsf@gnus.org> <877dpjp30g.fsf@ucl.ac.uk> <87zh2fnmwq.fsf@gnus.org> <87o8ivumn5.fsf@telefonica.net> <87v9d3nkxk.fsf@gnus.org> <87a6u4imxq.fsf@logand.com> <87v9cq43ns.fsf@logand.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="10287"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Dec 25 19:07:22 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ksrUn-0002Zf-SU for ged-emacs-devel@m.gmane-mx.org; Fri, 25 Dec 2020 19:07:21 +0100 Original-Received: from localhost ([::1]:49376 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ksrUm-0005kY-Os for ged-emacs-devel@m.gmane-mx.org; Fri, 25 Dec 2020 13:07:20 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:51016) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ksrUB-0005JR-19 for emacs-devel@gnu.org; Fri, 25 Dec 2020 13:06:43 -0500 Original-Received: from logand.com ([37.48.87.44]:39880) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ksrU9-0001yT-3b for emacs-devel@gnu.org; Fri, 25 Dec 2020 13:06:42 -0500 Original-Received: by logand.com (Postfix, from userid 1001) id 258C119F237; Fri, 25 Dec 2020 19:06:39 +0100 (CET) X-Mailer: emacs 26.3 (via feedmail 11-beta-1 I) In-Reply-To: Received-SPF: pass client-ip=37.48.87.44; envelope-from=tom@logand.com; helo=logand.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:261759 Archived-At: On Fri 25 Dec 2020 at 12:20, Stefan Monnier wrote: >> It is trivial for monochromatic documents. > > Actually, not even: if you've ever looked at the "negatives" used for > analog black&white photos you'll surely understand that inverse-video > doesn't work so well for images (mostly because it inverses lights and > shadows, thus confusing the semantics). Ok, I did not mean gray-scale. I meant text in black ink on white paper WYSIWYG edited in Emacs with reverse video colors. I cannot recall the proper name for it at the moment but you get the idea. Now add third color, e.g. to highlight a word in the document. Simply swapping background and foreground color can make the highlighted word badly readable, if the color stays the same. > For a "pure" text or other such circumstances where the colors don't > carry much meaning, it's not too hard to do something like "inverse > video" with an acceptable result, but for photos or comparable kinds > of images, I suspect that it's somewhere between very hard and > impossible. We can leave photos and images out of the question and simply preserve their colors. Do you have suggestion for automatically computing "it's not too hard" color mapping for "inverse video" "pure" text?