I agree this is how we arrived at mm/10 but we did this, mainly, as a
group of printer vendors. Now we are hearing from two groups of driver
developers (Nobert and my guys in Austin) who think otherwise. These are
(some of) the folks who will actually USE this information (aka... these
are our "customers").
----------------------------------------------
Harry Lewis
IBM Printing Systems
----------------------------------------------
RonBergman at aol.com
Sent by: owner-ipp at pwg.org
04/18/2001 05:00 PM
To: <harryl at us.ibm.com>, <robert.herriot at pahv.xerox.com>
cc: <hastings at cp10.es.xerox.com>, <ipp at pwg.org>
Subject: RE: IPP> Media Standardized Names - Units
Harry,
When we examined the metric sizes there were only a
few that had tenths of millimeters. That's why we
agreed to define the dimension as mm/10. I am not sure
why the concern for rounding, since if a device does
convert, it can maintain internally as much precision
as it desires. As long as there are no metric paper
sizes with dimensions of mm/100, there should not be a
problem.
With inch dimensions, there is always the possibility
of fractions, such as 1/3. But metric measurements
appear to be more civilized.
Ron
In a message dated Wed, 18 Apr 2001 5:38:55 PM Eastern Daylight Time,
"Harry Lewis" <harryl at us.ibm.com> writes:
<< Thanks, Bob.
----------------------------------------------
Harry Lewis
IBM Printing Systems
----------------------------------------------
"Herriot, Robert" <Robert.Herriot at pahv.xerox.com>
Sent by: owner-ipp at pwg.org
04/18/2001 02:26 PM
To: "Hastings, Tom N" <hastings at cp10.es.xerox.com>, Harry
Lewis
<harryl at us.ibm.com>, RonBergman at aol.com
cc: ipp at pwg.org
Subject: RE: IPP> Media Standardized Names - Units
Tom,
I disagree with your reasoning for why 1000th of an inch is closest to
10th
of a mm. A 0.1 mm is .0039 inch, or about 4 times less precise than .0010
inch. But a 100th of a mm is .0004 inch, or about 2.5 times more precise
than .0010 inch. To me, 2.5 seems like a closer match than 4.
> -----Original Message-----
> From: Hastings, Tom N [mailto:hastings at cp10.es.xerox.com]
> Sent: Tuesday, April 17, 2001 5:02 PM
> To: Harry Lewis; RonBergman at aol.com> Cc: ipp at pwg.org> Subject: RE: IPP> Media Standardized Names - Units
>>> Harry,
>> There are exactly 254 mm in an inch, so the precision is
> about the same, the
> inches are about 4 times more precise than the metric units.
>> For example, the two most popular Self Describing Size Names are:
>> The letter size (8.5 inches by 11 inches) used in North America:
> na-letter.8500-11000
> The iso A4 size (210 mm by 297 mm) used in metric countries:
> iso-a4.2100-2970
>> Note that they both have about the same number of digits in
> each dimension,
> namely around 4.
>> Also there isn't any need to convert from inches to mm or vice versa,
> because the paper size is given ONLY in the natural units for
> the usage. So
> North American sizes only use 1000ths of inches and aren't
> converted to mm.
> Similarly, the non-English sizes are always given in 10ths of
> mm and aren't
> converted to inches. Therefore, there is never any rounding
> errors to worry
> about.
>> The only rounding that could occur, is if some paper size is
> actually in
> some fraction of inches, or mm, such as 200 1/3 mm or 10 1/3
> inches. But I
> don't think we have any sizes like that.
>> Ok?
>> Tom
>> -----Original Message-----
> From: Harry Lewis [mailto:harryl at us.ibm.com]
> Sent: Monday, April 16, 2001 15:33
> To: RonBergman at aol.com> Cc: ipp at pwg.org> Subject: IPP> Media Standardized Names - Units
>>> I'm questioning the use of 1/1000 for English but only 1/10
> for metric.
> Not only are we loosing precision, but, also introducing
> rounding errors
> during conversion from English to metric . I know the printer
> MIB heritage
> is 1/1000 English and 1/10 metric... but
> I think we should try to be more precise in this new media mapping.
> ----------------------------------------------
> Harry Lewis
> IBM Printing Systems
> ----------------------------------------------
>>>>>RonBergman at aol.com> Sent by: owner-ipp at pwg.org> 04/09/2001 02:26 PM
>>> To: <ipp at pwg.org>, <upd at pwg.org>
> cc:
> Subject: IPP> Fwd: FW: Media Standardized
> Names, Version D0.6
> is now available
>>>>>> ----- Message from "Bergman, Ron"
> <Ron.Bergman at Hitachi-hkis.com> on Mon, 9
> Apr 2001 08:02:14 -0700 -----
> To:
> "'RonBergman at aol.com'" <RonBergman at aol.com>
> Subject:
> FW: Media Standardized Names, Version D0.6 is now available
>>> -----Original Message-----
> From: Bergman, Ron [mailto:Ron.Bergman at HITACHI-HKIS.COM]
> Sent: Monday, April 09, 2001 8:01 AM
> To: IMAGING at FORUM.UPNP.ORG> Subject: Media Standardized Names, Version D0.6 is now available
>>> All,
>> The latest draft is now available at:
>ftp://ftp.pwg.org/pub/pwg/media-sizes/pwg-media-06.pdf (or .doc)
I will not repeat the abstract here or the list of changes. This
information is
available within the document, if you are interested. The major change to
this
version is the addition of the "Media Finish Names".
This document will have a final review in the PWG meetings during the week
of April 23rd and should then be ready for last call.
Ron Bergman
Hitachi Koki Imaging Solutions
>>