From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Mathias Dahl Newsgroups: gmane.emacs.bugs Subject: Re: image-dired does not rotate the original image Date: Tue, 24 Jul 2007 08:52:59 +0200 Message-ID: References: <7dbe73ed0707220550k6cdc800asd2474266bcd6f1ed@mail.gmail.com> <874pjwpnoz.fsf@debby.local.net> <7dbe73ed0707220652w3d440b41m98a24248341486d@mail.gmail.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: sea.gmane.org 1185259995 10431 80.91.229.12 (24 Jul 2007 06:53:15 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 24 Jul 2007 06:53:15 +0000 (UTC) To: gnu-emacs-bug@moderators.individual.net Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Tue Jul 24 08:53:13 2007 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1IDEGY-0001oa-R4 for geb-bug-gnu-emacs@m.gmane.org; Tue, 24 Jul 2007 08:53:07 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IDEGY-0000HU-85 for geb-bug-gnu-emacs@m.gmane.org; Tue, 24 Jul 2007 02:53:06 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IDEGX-0000HP-5v for bug-gnu-emacs@gnu.org; Tue, 24 Jul 2007 02:53:05 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IDEGT-0000HD-MM for bug-gnu-emacs@gnu.org; Tue, 24 Jul 2007 02:53:04 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IDEGT-0000HA-JK for bug-gnu-emacs@gnu.org; Tue, 24 Jul 2007 02:53:01 -0400 Original-Received: from moderators.individual.net ([130.133.4.7]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1IDEGS-0005m1-Tp for bug-gnu-emacs@gnu.org; Tue, 24 Jul 2007 02:53:01 -0400 Original-Received: from outpost1.zedat.fu-berlin.de ([130.133.4.66]) by moderators.individual.net (Exim 4.67) for gnu-emacs-bug@moderators.individual.net with esmtp (envelope-from ) id <1IDEGR-00080I-Qn>; Tue, 24 Jul 2007 08:52:59 +0200 Original-Received: from relay1.zedat.fu-berlin.de ([130.133.4.67]) by outpost1.zedat.fu-berlin.de (Exim 4.66) for gnu-emacs-bug@moderators.individual.net with esmtp (envelope-from ) id <1IDEGR-00070W-Pw>; Tue, 24 Jul 2007 08:52:59 +0200 Original-Received: from curry.zedat.fu-berlin.de ([130.133.1.2]) by relay1.zedat.fu-berlin.de (Exim 4.66) for gnu-emacs-bug@moderators.individual.net with esmtp (envelope-from ) id <1IDEGR-0000nV-P5>; Tue, 24 Jul 2007 08:52:59 +0200 Original-Received: by Curry.ZEDAT.FU-Berlin.DE (Smail3.2.0.98) from news.uni-berlin.de with bsmtp id ; Tue, 24 Jul 2007 08:52:59 +0200 (MEST) Original-Path: individual.net!not-for-mail Original-Newsgroups: gnu.emacs.bug Original-Lines: 35 X-Orig-X-Trace: individual.net hD2Ac8WdP9jhpUUeA8zptAXq/mqnSMoLmKNgoR2mEwzATdXbWp Cancel-Lock: sha1:vdmUhHJMGgn+HVJ5KG+WXAX4Yws= sha1:QlaNT8fQ9V3RtIPulA9o8LZJWnE= User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (windows-nt) X-Originating-IP: 130.133.1.2 X-detected-kernel: Linux 2.6 (newer, 3) X-BeenThere: bug-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:16217 Archived-At: Thien-Thi Nguyen writes: > As I mentioned earlier, jpegtran does lossless rotation, something > `convert' cannot do (or could not the last time I checked). > > does this limitation also exist w/ mogrify(1) (or alternatively gm(1) > subcommand mogrify)? I don't know. What I do know is that `convert' makes a lossy rotation of JPEGs. I found this out myself while creating Tumme; while in the thumbnail buffer, rotate a thumbnail over and over again. Because of the small size you soon begin to see changes. > cp foo.jpg foo.orig.jpg > gm mogrify -rotate -90 foo.jpg > gm mogrify -rotate 90 foo.jpg > cmp foo.jpg foo.orig.jpg > > however, doing the above (even w/ "-quality 100" for the mogrify commands) > always results in cmp(1) noting a difference, even though visually i could > not tell. If you do that in a loop, say ten or more times, maybe you will start to see a difference (save the original and compare it visually). > i'm not a graphics format expert; could you suggest a better > way to check for loss? How about rotating the image in Gimp, for comparison? Maybe there should be an option in `image-dired' to allow lossy rotation, so that people who accept that do not need to have `jpegtran'? /Mathias