[Proj] Is it possible to store a WGS84 / Pseudo Mercator image as a GeoTIFF?

Mikael Rittri Mikael.Rittri at carmenta.com
Sun Feb 8 10:42:21 EST 2015


Many thanks for the valuable information, both Noel and Even. 

Even: I will have to spend some time digesting your
detailed information about GeoTIFF. Unless I can just
summarize it in my report, by saying that the GeoTIFF
format supports Pseudo-Mercator in some sense, but there
is no explicit representation of the "Popular Visualisation
Pseudo Mercator" map projection method as a method
separate from the kosher Ellipsoid Mercator projection
method, so it is necessary that the EPSG code 3857 is
attached to the CRS definition. (That sentence was long!)
And that some GeoTIFF readers have problems anyway. 

Noel: I was aware of the NGA advisory notice (it is, in fact,
the reason why I have been asked to write my report). 
But I was completely unaware of the journal article you
mentioned. It would have been a pity if I had neglected it. 
Many thanks.
 
      Also, "tolerated" is okay, I can live with that. In fact,
it must be said that after the EPSG  committee decided to
to tolerate it, they are tolerating it with good grace, handling related
change requests and related new  requests almost as if they had
"adopted" it willingly. 
Maybe they are secretly gritting their teeth, of course. 

Best regards,

Mikael Rittri
Carmenta
Sweden
http://www.carmenta.com

8 feb 2015 kl. 14:35 skrev "Noel Zinn (cc)" <ndzinn at comcast.net>:

> Andre,
> 
> "Adopted" connotes acceptance.  Perhaps "tolerated" is closer to the truth.
> 
> Mikael,
> 
> If you're not aware of "Implications of Web Mercator and Its Use in Online 
> Mapping", by Battersby, Finn, Usery and Yamamoto (Cartographica 2014), 
> here's a link:
> 
> http://www.researchgate.net/publication/265895464_Implications_of_Web_Mercator_and_Its_Use_in_Online_Mapping
> 
> And even "tolerated" connotes too much acceptance for the US National 
> Geospatial-Intelligence Agency.  See link following:
> 
> http://earth-info.nga.mil/GandG/wgs84/web_mercator/
> 
> Noel
> 
> Noel Zinn, Principal, Hydrometronics LLC
> +1-832-539-1472 (office), +1-281-221-0051 (cell)
> noel.zinn at hydrometronics.com (email)
> http://www.hydrometronics.com (website)
> 
> -----Original Message----- 
> From: Andre Joost
> Sent: Sunday, February 08, 2015 6:46 AM
> To: proj at lists.maptools.org
> Subject: Re: [Proj] Is it possible to store a WGS84 / Pseudo Mercator image 
> as a GeoTIFF?
> 
> Hi Mikael,
> 
> You should probably ask "since when it is supported correctly?".
> 
> I remember that EPSG:900913 was rejected by EPSG and GIS professionals
> for a long time, until it was adopted as EPSG:3857.
> 
> And there were several complaints about misalignments of abot 20km to
> the North, due to the non-standard transformation Google had invented.
> 
> EPSG:3395 and EPSG:3785 were some steps on the right way.
> 
> As a reference, you can look for older versions of QGIS including GDAL
> and PROJ at http://qgis.org/downloads/ back to 2010.
> 
> http://www.gisinternals.com/archive.php dates back to GDAL 1.7.3
> 
> FWtools http://fwtools.maptools.org/ might still be older.
> 
> Greetings,
> André Joost
> 
> Am 08.02.2015 um 11:26 schrieb Mikael Rittri:
>> And if it is possible, since when or what version of
>> GeoTIFF? And do most GeoTIFF readers support it?
>> 
>> (I apologize if this is the wrong mailing list for the questions.)
>> 
>> I am writing a report on Pseudo Mercator, and I realized
>> that I don't know how well it is supported in GeoTIFF.
>> 
>> Best regards,
>> 
>> Mikael Rittri
>> Carmenta
>> Sweden
>> http://www.carmenta.com
>> _______________________________________________
>> Proj mailing list
>> Proj at lists.maptools.org
>> http://lists.maptools.org/mailman/listinfo/proj
>> 
> 
> 
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