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 16:18:46 +0100 Message-ID: <482319D6.1020308@gnu.org> References: <87ve1pdnjq.fsf@stupidchicken.com> <4822EC6F.6000703@gnu.org> <87zlr0yh2y.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 1210259979 27408 80.91.229.12 (8 May 2008 15:19:39 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 8 May 2008 15:19:39 +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 17:20:14 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 1Ju7ud-0002nQ-8Y for ged-emacs-devel@m.gmane.org; Thu, 08 May 2008 17:20:04 +0200 Original-Received: from localhost ([127.0.0.1]:46395 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ju7tt-0007X1-QU for ged-emacs-devel@m.gmane.org; Thu, 08 May 2008 11:19:17 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Ju7tj-0007Qi-Di for emacs-devel@gnu.org; Thu, 08 May 2008 11:19:07 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Ju7te-0007Mq-OV for emacs-devel@gnu.org; Thu, 08 May 2008 11:19:06 -0400 Original-Received: from [199.232.76.173] (port=50189 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ju7te-0007Mi-Gx for emacs-devel@gnu.org; Thu, 08 May 2008 11:19:02 -0400 Original-Received: from mk-outboundfilter-4.mail.uk.tiscali.com ([212.74.114.32]:28538) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Ju7tW-0000y4-MT; Thu, 08 May 2008 11:18:55 -0400 Original-X-Trace: 76918529/mk-outboundfilter-2.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: AqsEAMK2IkhTQxds/2dsb2JhbACBU6o+ 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 16:18:52 +0100 Original-Received: from [192.168.249.27] (chiko.jasonrumney.net [192.168.249.27]) by wanchan.jasonrumney.net (Postfix) with ESMTP id 3D4451488; Thu, 8 May 2008 16:18:52 +0100 (BST) User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) In-Reply-To: <87zlr0yh2y.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:96788 Archived-At: Miles Bader wrote: > Perhaps there's some header info that emacs wants which isn't there? > > I write the header like: > > png_set_IHDR (libpng_struct, libpng_info, width, height, > 8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, > PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); > png_set_gAMA (libpng_struct, libpng_info, gamma_correction); > Is there any program that can dump a PNG header in some readable format, so we can compare yours with the image that Gimp saves? Or maybe someone needs to step through the PNG display code in Emacs, and see where it (or libpng) makes the wrong decision.