Re: [Bimi] [rfc-i] SVG P/S Feedback

Brian E Carpenter <brian.e.carpenter@gmail.com> Sat, 29 August 2020 05:04 UTC

Return-Path: <brian.e.carpenter@gmail.com>
X-Original-To: bimi@ietfa.amsl.com
Delivered-To: bimi@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 70F883A1093 for <bimi@ietfa.amsl.com>; Fri, 28 Aug 2020 22:04:09 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.046
X-Spam-Level:
X-Spam-Status: No, score=-3.046 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, NICE_REPLY_A=-0.948, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Zy5phTjKgFox for <bimi@ietfa.amsl.com>; Fri, 28 Aug 2020 22:04:07 -0700 (PDT)
Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id DA7E43A1092 for <bimi@ietf.org>; Fri, 28 Aug 2020 22:04:07 -0700 (PDT)
Received: by mail-pj1-x102b.google.com with SMTP id nv17so502445pjb.3 for <bimi@ietf.org>; Fri, 28 Aug 2020 22:04:07 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=HiJpd0Yp5y1V3IjWRoh7O1YD39N8m2jXdz6ntbrag30=; b=pVaZ3xJL8qxrmO16R9zvtLNuztOMjSfJdD222c6sXpXFoxKhfMKmtOZ/K6KGAcrf/e q3BKT1/cFwpwEC3LXR9LN6AYOiUYjDt0LindrbBpSce6hlCpSeii+GU2a/lULFUB5euN eMDRTJVrQmm6IYGXu4WOakP5lsUvdL5FnDi/Vw6e4s1ayJvpDL9gT+SwB9KYKlpEIvXz X0X5EjQlNeYU3fu+E64AMpYZOJiLrryW4rZcMO+AjpCGfxo4sImbRdjO+hwp2BeSumIe iCyU2xjUZaFVAczBFzRxTxq0JK9zsxn/NCZvJQLjCxc64SQgCQETV8xQpBqJQdi26psQ beDQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=HiJpd0Yp5y1V3IjWRoh7O1YD39N8m2jXdz6ntbrag30=; b=VFoqS/wkgTMoGN6NZoJSPCs5xmPyez6vpIiOlioNPPFjtaNu84fQ7E19HSqCdSf15R 2umgkkbCMtTsP8LkkicC5r8bUXLRVAmdo+RvlFTdQUL5LOs8N+DweEN57oTj6YA7+w7s bPR3grZmYl+p3ifUIe4RZtpgtAeWyfZFIOEzKETxTcRCfYDnaanULqB0Hxx5M0BmYsbR kUMXKOYuqBbFOL8dyEXTHqVQPTeq6LNoZW56Sx3H/o5404a1RXUMUqLFBsnugziuZmAa urRzGaNSS7nsOm5fj27/+tdIAA+I6MZFt0VnKGkdxeCy7k3fWPjCZr1sT0mix35rNRhs yQxQ==
X-Gm-Message-State: AOAM530hgi4pMSSSpKscoC9V/VwWZZXcPZsHQyE+6dzu3kW2zuAiwAX/ PA9LgFxY7I/KAMggw1/vSNbtPbfWgLqxSA==
X-Google-Smtp-Source: ABdhPJwEO3LLl3Nan82AWdIFJ1hMsJoHW7OCtUn3/oL0sWQBK+TwdOGhJaaSl09Vi1ZCO4UluZrxjA==
X-Received: by 2002:a17:90a:ab91:: with SMTP id n17mr1905474pjq.84.1598677447124; Fri, 28 Aug 2020 22:04:07 -0700 (PDT)
Received: from [192.168.178.20] ([151.210.139.192]) by smtp.gmail.com with ESMTPSA id x7sm1088228pff.110.2020.08.28.22.04.04 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 Aug 2020 22:04:06 -0700 (PDT)
To: Larry Masinter <LMM@acm.org>, "'Brotman, Alex'" <Alex_Brotman@comcast.com>, rfc-interest@rfc-editor.org
Cc: "'BIMI (IETF)'" <bimi@ietf.org>
References: <MN2PR11MB4351CC443B406196C3953D1BF7520@MN2PR11MB4351.namprd11.prod.outlook.com> <70eadfe5-16f6-47d9-4cb8-f4f9bffdd355@gmail.com> <013c01d67d8e$5b952f60$12bf8e20$@acm.org>
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Message-ID: <f2df89d0-73c5-49b5-c18c-ec0ac16dfa1c@gmail.com>
Date: Sat, 29 Aug 2020 17:04:02 +1200
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1
MIME-Version: 1.0
In-Reply-To: <013c01d67d8e$5b952f60$12bf8e20$@acm.org>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/bimi/B1GGIBZ4RrLq7wX29JojsjODREI>
Subject: Re: [Bimi] [rfc-i] SVG P/S Feedback
X-BeenThere: bimi@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Brand Indicators for Message Identification <bimi.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/bimi>, <mailto:bimi-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/bimi/>
List-Post: <mailto:bimi@ietf.org>
List-Help: <mailto:bimi-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/bimi>, <mailto:bimi-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 29 Aug 2020 05:04:09 -0000

Larry,

On 29-Aug-20 10:55, Larry Masinter wrote:
> One of the functional requirements for SVG illustrations is that when
> converted to PDF/A that the result is "as good as it gets" so the authors
> don't rely on embedded animations or videos to explain the protocol they are
> describing.
> 
> What if you did a round trip   SVG -> PDF/A -> SVG. I think it's possible to
> insure that doing so is idempotent (if it isn't now).

Only if you had a round trip tool that magically preserves the SVG dialect
in use. I just round-tripped a test file using https://convertio.co.
The PDF and the round-tripped SVG *look* the same as the original, but the
actual content of the SVG file is totally different, and fails svgcheck, so
is no longer conformant with RFC7996. The converter just happens to choose
a different way of representing the same image, since SVG is so versatile.

The converter also messed up the scalability of the image, which is really
annoying if you want the image to be viewable on a tiny screen.

Now I'll round-trip it a second time... once again, the input and output
SVG files are different, although only in a few places. So even the
conversion tools at convertio.co can't achieve idempotency with the SVG
that they themselves generate.

(For the record, convertio.co doesn't claim to be PDF/A conformant,
but I think that's beside the point here.)

   Brian