From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Jason Rumney Newsgroups: gmane.emacs.devel Subject: Re: PNG image files with alpha channel Date: Thu, 08 May 2008 16:51:04 +0100 Message-ID: <48232168.7070907@gnu.org> References: <87ve1pdnjq.fsf@stupidchicken.com> <4822EC6F.6000703@gnu.org> <87zlr0yh2y.fsf@catnip.gol.com> <482319D6.1020308@gnu.org> <87tzh8yfdc.fsf@catnip.gol.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1210261899 2141 80.91.229.12 (8 May 2008 15:51:39 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 8 May 2008 15:51:39 +0000 (UTC) Cc: Chong Yidong , emacs-devel@gnu.org To: Miles Bader Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu May 08 17:52:15 2008 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1Ju8Pk-0000Nr-8m for ged-emacs-devel@m.gmane.org; Thu, 08 May 2008 17:52:12 +0200 Original-Received: from localhost ([127.0.0.1]:45298 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ju8P2-0005sT-0y for ged-emacs-devel@m.gmane.org; Thu, 08 May 2008 11:51:28 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Ju8Ov-0005sD-77 for emacs-devel@gnu.org; Thu, 08 May 2008 11:51:21 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Ju8Ot-0005qh-O5 for emacs-devel@gnu.org; Thu, 08 May 2008 11:51:20 -0400 Original-Received: from [199.232.76.173] (port=34885 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ju8Ot-0005qI-FP for emacs-devel@gnu.org; Thu, 08 May 2008 11:51:19 -0400 Original-Received: from mk-outboundfilter-3.mail.uk.tiscali.com ([212.74.114.23]:33124) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Ju8Oo-0007xh-Q5; Thu, 08 May 2008 11:51:14 -0400 Original-X-Trace: 112283794/mk-outboundfilter-1.mail.uk.tiscali.com/F2S/$ACCEPTED/freedom2Surf-customers/83.67.23.108 X-SBRS: None X-RemoteIP: 83.67.23.108 X-IP-MAIL-FROM: jasonr@gnu.org X-IP-BHB: Once X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqsEAI69IkhTQxds/2dsb2JhbACBU6pA X-IP-Direction: IN Original-Received: from i-83-67-23-108.freedom2surf.net (HELO wanchan.jasonrumney.net) ([83.67.23.108]) by smtp.f2s.tiscali.co.uk with ESMTP; 08 May 2008 16:51:13 +0100 Original-Received: from [192.168.249.27] (chiko.jasonrumney.net [192.168.249.27]) by wanchan.jasonrumney.net (Postfix) with ESMTP id ACFB11488; Thu, 8 May 2008 16:51:11 +0100 (BST) User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) In-Reply-To: <87tzh8yfdc.fsf@catnip.gol.com> X-Enigmail-Version: 0.95.6 OpenPGP: id=8086879D X-detected-kernel: by monty-python.gnu.org: Genre and OS details not recognized. X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:96794 Archived-At: Miles Bader wrote: > So the problem may in fact be something with the libpng 16-to-8-bit > conversion code... > We may need to explicitly tell it to preserve alpha when it does this transformation. Gimp must do something similar, as it only supports 8 bits per channel internally, and it displays the transparency OK.