From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 4FAA51382C5 for ; Tue, 5 Jan 2021 02:55:29 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id C6012E086C; Tue, 5 Jan 2021 02:55:23 +0000 (UTC) Received: from pmta21.teksavvy.com (pmta21.teksavvy.com [76.10.157.36]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 56A48E085A for ; Tue, 5 Jan 2021 02:55:23 +0000 (UTC) IronPort-SDR: JkgK9zJlnlmpFW2pyLOk0DzrlFaw6exYUBL6juyPLJHypYq+dfTpOVqBS/96LyS0pY/wTiVPoi SlIJaiql4ogA== X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A2HaBwDz0/Nf/yHkSC1igQkHgUiDeGG?= =?us-ascii?q?Ic4RQhheCUJoDgXwLAQEBAQEBAQEBHBkBAgQBAYFVgm8EAgKBcSY2Bw4CAwE?= =?us-ascii?q?BCwEBAQUBAQEBAQYEAgKGWoZRBjocMws0EhBHGYYtrwCBNIVYhGyBOI0pQT+?= =?us-ascii?q?BAj+DfC4+hQuFKwSEAIEAEjN3L48kjQmbUQqCdoEYBppcgymKK4U6j0K3RAJ?= =?us-ascii?q?pgSB9CIMkUBkNV5wxJjA3AgYKAQEDCVcBjRMBAQ?= X-IPAS-Result: =?us-ascii?q?A2HaBwDz0/Nf/yHkSC1igQkHgUiDeGGIc4RQhheCUJoDg?= =?us-ascii?q?XwLAQEBAQEBAQEBHBkBAgQBAYFVgm8EAgKBcSY2Bw4CAwEBCwEBAQUBAQEBA?= =?us-ascii?q?QYEAgKGWoZRBjocMws0EhBHGYYtrwCBNIVYhGyBOI0pQT+BAj+DfC4+hQuFK?= =?us-ascii?q?wSEAIEAEjN3L48kjQmbUQqCdoEYBppcgymKK4U6j0K3RAJpgSB9CIMkUBkNV?= =?us-ascii?q?5wxJjA3AgYKAQEDCVcBjRMBAQ?= X-IronPort-AV: E=Sophos;i="5.78,475,1599537600"; d="scan'208";a="151792075" Received: from 45-72-228-33.cpe.teksavvy.com (HELO waltdnes.org) ([45.72.228.33]) by smtp12.teksavvy.com with SMTP; 04 Jan 2021 21:55:21 -0500 Received: by waltdnes.org (sSMTP sendmail emulation); Mon, 04 Jan 2021 21:55:43 -0500 From: "Walter Dnes" Date: Mon, 4 Jan 2021 21:55:43 -0500 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Your opinion on jpeg encoders, please Message-ID: References: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Archives-Salt: 58175875-3b58-4a68-b871-d123969c9eab X-Archives-Hash: 8a0591b25c6c9b0ed47ce8001b50a0b8 On Mon, Jan 04, 2021 at 10:37:34PM +0100, Frank Steinmetzger wrote > > When I edit photos, I like to shrink and recompress them to save on > space, but not mangle them too much in the process to lose quality. Actually, shrinking *BY AN INTEGER NUMBER SHOULD IMPROVE QUALITY* as well as saving space. In Google look up the phrase... photography binning adjacent pixel If you bin a 3840x2160 image by 2, you'll get a 1920x1080 result. If you bin it by 3, you'll get 1280x720 image. The math is a bit convoluted, but when you bin by a value of "n"... * the information per combined pixel increases by a factor of "n" * the noise per combined pixel increases by a factor of square root of "n" So the "signal-to-noise-ratio" increases. The resulting image is less noisey. The tradeoff is that the new image is smaller than the original. I use the imagemagick "convert" utility from the commandline, but any capable image software should work. -- Walter Dnes I don't run "desktop environments"; I run useful applications