Re: Adding scale, offset, units metadata to geotiff

• To: warmerdam@xxxxxxxxx
• Subject: Re: Adding scale, offset, units metadata to geotiff
• From: Rob Raskin <raskin@xxxxxxxxxxxxxxxxxxxx>
• Date: Wed, 13 Jul 2005 15:36:58 -0700

Yes.  That is what I am suggesting.  This is mentioned in the GeoTIFF
specs as a possible use for that parameter pair.  Given that there is no
concept of raster spacing in the vertical direction, how else might you
interpret the vertical scaling parameters?  Even if we created 2-D
vertical-longitude profiles, these should have x- and y- axes within the
GeoTIFF, for broswers and other software to render correctly.

-Rob


Frank Warmerdam wrote:

On 7/13/05, Rob Raskin <raskin@xxxxxxxxxxxxxxxxxxxx> wrote:

GeoTIFF alrady includes the option for scale and offset in the
"z-direction".  But most client tools (including ArcGIS) ignore that
tag.

It isn't clear why this information was added to the private GDAL tag.

Rob,

Are you suggesting that the "z" direction of the geotransmatrix
is intendeded to be interpreted as offset and scaling for pixel
values?   I never took it that way in the past.

Perhaps you mean something else, and could clarify.

• Follow-Ups:
  • Re: Adding scale, offset, units metadata to geotiff
    • From: Frank Warmerdam

• References:
  • Adding scale, offset, units metadata to geotiff
    • From: John Caron
  • Re: Adding scale, offset, units metadata to geotiff
    • From: Rob Raskin
  • Re: Adding scale, offset, units metadata to geotiff
    • From: Frank Warmerdam