Return-Path: <awaresystems.be+caf_=filtered=awaresystems.be@gmail.com>
Delivered-To: <filtered@awaresystems.be>
Received: from mx2.public.one.com ([10.246.18.22])
	by mail6.local.one.com (Dovecot) with LMTP id r4QRE3HwuFdhfgAAsyOMew
	for <filtered@awaresystems.be>; Sun, 21 Aug 2016 00:06:40 +0000
X-HalOne-ID: 21075632-6733-11e6-b666-b82a72d88088
Received: from mail-qk0-f180.google.com (unknown [209.85.220.180])
	by mx2.public.one.com (Halon Mail Gateway) with ESMTPS
	for <filtered@awaresystems.be>; Sun, 21 Aug 2016 00:06:37 +0000 (UTC)
Received: by mail-qk0-f180.google.com with SMTP id l2so66546179qkf.3
        for <filtered@awaresystems.be>; Sat, 20 Aug 2016 17:06:37 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20130820;
        h=x-original-authentication-results:x-gm-message-state:delivered-to
         :date:from:to:in-reply-to:message-id:references:user-agent
         :mime-version:cc:subject:precedence:list-id:list-unsubscribe
         :list-archive:list-post:list-help:list-subscribe
         :content-transfer-encoding:sender:errors-to;
        bh=FDpMyd9bOUrlZeRcoJEY6F0FCgZDrMyJ32J/8NkyOFI=;
        b=CLJCvS77bng5Y9RFiBaEe0IdsQA6yaR4aypbA15Qm/9vGPAzKzwSQ1MtFO4W+UJkKf
         qxWAAFPMqHkWkoNQOWpzLh7YbykdjJV5yUPaBhTOImFOCmaZ5YcgolBXcJQMCMsruVkP
         VHqOqaCPizbJF+rZNW6LGk3FnXtNItoRY8RyZZsElQlIjdDBtimbp8wNPwI0+oiUUoAr
         Q5WeqW6F+/QW+/LRVC+FbcmjNlI3tlQ8z82ydV7BuJIf9pH9TORPIwOR8ALvSdEYEtyN
         9QFvTWrtE6GWVWtvxrufMdzORwR3q+lACH44OYXzLbhcLxwrUTYqeAH3zL2Xkv8iiBCr
         dZxQ==
X-Original-Authentication-Results: mx.google.com;       spf=neutral (google.com: 94.23.4.142 is neither permitted nor denied by best guess record for domain of tiff-bounces@lists.maptools.org) smtp.mailfrom=tiff-bounces@lists.maptools.org
X-Gm-Message-State: AEkooutL7ZK2r0suHeBKiQh2J3sJzugs7+BvVnJAzvDEsAzWC4IxESb9Z6AebCW8NJCVhblWTJqKnNn0QH4vQmFuweRz0vk=
X-Received: by 10.55.67.139 with SMTP id q133mr15484317qka.71.1471737996201;
        Sat, 20 Aug 2016 17:06:36 -0700 (PDT)
X-Forwarded-To: filtered@awaresystems.be
X-Forwarded-For: awaresystems.be@gmail.com filtered@awaresystems.be
Delivered-To: awaresystems.be@gmail.com
Received: by 10.55.75.193 with SMTP id y184csp906408qka;
        Sat, 20 Aug 2016 17:06:35 -0700 (PDT)
X-Received: by 10.194.110.102 with SMTP id hz6mr11536786wjb.5.1471737995351;
        Sat, 20 Aug 2016 17:06:35 -0700 (PDT)
Return-Path: <tiff-bounces@lists.maptools.org>
Received: from lists.maptools.org (ks365428.kimsufi.com. [94.23.4.142])
        by mx.google.com with ESMTP id d206si9910832wmf.111.2016.08.20.17.06.35;
        Sat, 20 Aug 2016 17:06:35 -0700 (PDT)
Received-SPF: neutral (google.com: 94.23.4.142 is neither permitted nor denied by best guess record for domain of tiff-bounces@lists.maptools.org) client-ip=94.23.4.142;
Authentication-Results: mx.google.com;
       spf=neutral (google.com: 94.23.4.142 is neither permitted nor denied by best guess record for domain of tiff-bounces@lists.maptools.org) smtp.mailfrom=tiff-bounces@lists.maptools.org
Received: from [10.1.0.241] (localhost.localdomain [127.0.0.1])
	by lists.maptools.org (Postfix) with ESMTP id B13AF35C0BD;
	Sat, 20 Aug 2016 19:03:41 -0500 (EST)
Received: from smtp.simplesystems.org (smtp.simplesystems.org [65.66.246.90])
	by lists.maptools.org (Postfix) with ESMTPS id 747F835C0B1
	for <tiff@lists.maptools.org>; Sat, 20 Aug 2016 18:47:11 -0500 (EST)
Received: from freddy.simplesystems.org (freddy.simplesystems.org
	[65.66.246.65])
	by smtp.simplesystems.org (8.14.4+Sun/8.14.4) with ESMTP id
	u7KNl7xn017024; Sat, 20 Aug 2016 18:47:07 -0500 (CDT)
Date: Sat, 20 Aug 2016 18:47:07 -0500 (CDT)
From: Bob Friesenhahn <bfriesen@simple.dallas.tx.us>
X-X-Sender: bfriesen@freddy.simplesystems.org
To: yufengs@andrew.cmu.edu
In-Reply-To: <fa7454af55fcc3209dadf475357b7e86.squirrel@webmail.andrew.cmu.edu>
Message-ID: <alpine.GSO.2.20.1608201837190.6191@freddy.simplesystems.org>
References: <09dde6240493ffe94842757b13dc3507.squirrel@webmail.andrew.cmu.edu>
	<alpine.GSO.2.20.1608201427590.6191@freddy.simplesystems.org>
	<fa7454af55fcc3209dadf475357b7e86.squirrel@webmail.andrew.cmu.edu>
User-Agent: Alpine 2.20 (GSO 67 2015-01-07)
MIME-Version: 1.0
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16
	(smtp.simplesystems.org [65.66.246.90]);
	Sat, 20 Aug 2016 18:47:07 -0500 (CDT)
Cc: TIFF <tiff@lists.maptools.org>
Subject: Re: [Tiff] 32 bits per sample
X-BeenThere: tiff@lists.maptools.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: TIFF and libtiff discussion <tiff.lists.maptools.org>
List-Unsubscribe: <http://lists.maptools.org/mailman/listinfo/tiff>,
	<mailto:tiff-request@lists.maptools.org?subject=unsubscribe>
List-Archive: <http://lists.maptools.org/mailman/private/tiff>
List-Post: <mailto:tiff@lists.maptools.org>
List-Help: <mailto:tiff-request@lists.maptools.org?subject=help>
List-Subscribe: <http://lists.maptools.org/mailman/listinfo/tiff>,
	<mailto:tiff-request@lists.maptools.org?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: tiff-bounces@lists.maptools.org
Errors-To: tiff-bounces@lists.maptools.org

On Sat, 20 Aug 2016, yufengs@andrew.cmu.edu wrote:
>
> And I also uploaded it (named
> 'Yufeng.tiff') to ftp.graphicsmagick.org/incoming/graphicsmagick
> I'm
> sorry it's a little big, about 25MB.

Your floating point TIFF uses an unusual range.  Unfortunately, it is 
usually necessary to read the TIFF data twice in order to know how to 
properly scale the data for viewing.

Through a bit of trial and error I found that the data 
ranges from 0.0 to 0.01.  GraphicsMagick defaults to 0.0 to 1.0.

I am able to make sense of your data like

   gm convert -define tiff:min-sample-value=0.0 \
     -define tiff:max-sample-value=0.01 Yufeng.tiff Yufeng.jpg

Using

   gm convert -define tiff:min-sample-value=0.0 \
     -define tiff:max-sample-value=0.01 Yufeng.tiff \
     -gamma 2.2 Yufeng.jpg

helps when displaying the image on a computer.

Bob
-- 
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
_______________________________________________
Tiff mailing list: Tiff@lists.maptools.org
http://lists.maptools.org/mailman/listinfo/tiff
http://www.remotesensing.org/libtiff/
