[Mapserver-users] I have some landsat 7 data that I want to tile : overlap + transparency

[Stephen Clark]

Frank,

Point taken about the return receipt requested set on.  Will turn it off.


I am not sure what the problem is with these ECW files.  I think that it is
the TRANSPARENCY but am not sure.
I downloaded the TIFF files and then compresed them to ECW then used
gdaltindex on them to create a tile.

Files:
My landsat data is from the Geogratis web site :

http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/utm/

Specifically these three scenes as example:

http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/utm/047021/
http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/utm/048021/
http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/utm/049021/


Note: Creating a tile using the raw TIFF files produces no "Black Fuzziness
around the scenes "

Stephen Clark wrote:
> There is a residual amount of black fuzziness around the scenes after
using
> the above OFFSITE command.
That is pretty much inevitable if you use ECW.  Lossy compression formats
will not maintain nodata areas cleanly.


Q1: Is there a way of specifying a range of values for the OFFSITE command
to handle the lossy compression fuzziness?

Q2: The transparency values do not work for a tiled raster file (TIFF and
ECW) using the links posted above.  It believe it to be an error.


> I am not eager to allow different offsite values for each file selected
from
> the tileindex.  However, if there is one offsite value in your layer
definition
> it should be used for all the tiles in the layer.  Is this not happening?
Or
> was it layer transparency (ala TRANSPARENCY keyword) that was not working?
I
> think I asked this before and then lost your answer in the flood of
> correspondence on the issue.
>


Q3: I would like the ability to specify an individual TRANSPARENCY and
OFFSITE value for each raster file before creating a tile.  That way I could
create a mosaic from many raster files and have the best part of each image
viewable.  Would this be a tremendous amount of work?

Thanks
Stephen



----- Original Message ----- 
From: "Frank Warmerdam" <warmerdam at pobox.com>
To: "Stephen Clark" <stephen.clark at focus.ca>
Sent: Monday, February 02, 2004 12:40 PM
Subject: Re: [Mapserver-users] I have some landsat 7 data that I want to
tile : overlap + transparency


> Stephen Clark wrote:
> > Frank,
> >
> > Did you get the attached images I sent regarding this issue?  The issue
> > relates to me wanting to produce 300 DPI images in a PDF using the
Landsat 7
> > data.
>
> Stephen,
>
> I did get a pointer to where to download them from, but I didn't do that.
> I have no opinion on all the scale related issues.
>
> >>My use of Landsat 7 Imagery is for a backdrop in my PDF files.  But I
> >>cannot get the WMS server to produce a 300 dpi image so I need to copy
> >>them locally to produce the 300 dpi PDF files.
> >>
> >
> >
> > I am working on using the BBOX, Width and Height parameters instead but
I
> > have had no luck.
> >
> > The original problem I posed to you was why I could not place
transparency
> > in each Landsat scene as I created the Tiled index using GdalTindex.  So
> > what do you think on the this issue?
>
> I am not eager to allow different offsite values for each file selected
from
> the tileindex.  However, if there is one offsite value in your layer
definition
> it should be used for all the tiles in the layer.  Is this not happening?
Or
> was it layer transparency (ala TRANSPARENCY keyword) that was not working?
I
> think I asked this before and then lost your answer in the flood of
> correspondence on the issue.
>
> PS. it's a bit annoying to have return receipt requested set on.  The only
> time I do this is with the property manager at our condo because she is so
> slack about replying.  It kinds of makes me feel like a kid being checked
up
> on!
>
> Best regards,
>
> -- 
> ---------------------------------------+----------------------------------
----
> I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial Programmer for Rent
>
>
>