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 6BB771382C5 for ; Mon, 1 Mar 2021 12:02:20 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id E3D85E0980; Mon, 1 Mar 2021 12:02:13 +0000 (UTC) Received: from mout-p-102.mailbox.org (mout-p-102.mailbox.org [IPv6:2001:67c:2050::465:102]) (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 30F76E092F for ; Mon, 1 Mar 2021 12:02:12 +0000 (UTC) Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:105:465:1:1:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-102.mailbox.org (Postfix) with ESMTPS id 4DpzQR4TDnzQlZX for ; Mon, 1 Mar 2021 13:02:07 +0100 (CET) X-Virus-Scanned: amavisd-new at heinlein-support.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxkompis.se; s=MBO0001; t=1614600125; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=01Md6JTN5QadkUcULB8yxcySQDMT9rqV3MUebmuZl9s=; b=cmssIpkfJDgUcS6eSaUMImTp+U/It+LplbvPV8GPvLj0WGL2168MorwPMXsX9vbZOGSwJ3 IDT4BIh04wKgGGc710goewfn7pR0vOOa13E32qIUFMH7Xv631v8ZYDPBaQZSQ0N5tknO8D abQfkEn7mWD1FLuow7tUNEBIVS6sEwAywu0W1bfiZkt4LiQ5vL3boTwN/OAIG+5VjaQFta 7j30sC5AoYrZoMJE5t25CsND3qrnvGHDbDTjJxOrTtU3UIS/7P3+jtEHDQtr+5httoFDBe cb/WTRlVIeWyo0RVjpRBxXJ8+GKOkuntGHcvfWL65gYBPg6aLIKQ3BxtMlNNHQ== Received: from smtp1.mailbox.org ([80.241.60.240]) by spamfilter03.heinlein-hosting.de (spamfilter03.heinlein-hosting.de [80.241.56.117]) (amavisd-new, port 10030) with ESMTP id 7olOcbiJw8a8 for ; Mon, 1 Mar 2021 13:02:01 +0100 (CET) Date: Mon, 01 Mar 2021 13:01:59 +0100 From: Hund To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] [OT] Saving an image as black and white In-Reply-To: <603CD50B.9080303@youngman.org.uk> References: <603CD50B.9080303@youngman.org.uk> Message-ID: <552B1EA0-0140-4911-9F9D-4DBA2B3F80EB@linuxkompis.se> 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=utf-8 Content-Transfer-Encoding: quoted-printable X-MBO-SPAM-Probability: X-Rspamd-Score: -7.20 / 15.00 / 15.00 X-Rspamd-Queue-Id: 57C921860 X-Rspamd-UID: 89ceec X-Archives-Salt: 93dafa6a-3e3d-47e6-ab09-daafa84b6899 X-Archives-Hash: 6f75ba496cbb8d34723ab6adb0eba171 On March 1, 2021 12:50:35 PM GMT+01:00, Wols Lists wrote: >I've got a bunch of scans, let's assume they're text documents=2E And >they're rather big =2E=2E=2E I want to email them=2E > >How on earth do I convert them to TRUE b&w documents? At the moment they >are jpegs that weigh in at 3MB, and I guess they're using about 5 bytes >to store all the colour, luminance, whatever, per pixel=2E But actually, >there's only ONE BIT of information there - whether that pixel is black >or white=2E > >I'm using imagemagick, but so far all my attempts to strip out the >surplus information have resulted in INcreasing the file size ??? > >So basically, how do I save an image as "one bit per pixel" like you'd >think you'd send to a B&W printer? > >Even at 300dpi, I make that 300*300/8 ~=3D 10KB/in^2 or 800KB of >uncompressed info for a page of A4, not 3MB=2E > >Cheers, >Wol > Have you tried an optical character recognition software like Tesseract[1]= ? 1=2E https://github=2Ecom/tesseract-ocr/tesseract -- Hund