[gdal-dev] GeoTIFF to Shapefile

2011-03-24 Thread Emilio de Torres Fernández
Hello,

I have GeoTIFF files and need to get a shapefile with the contour of
each one. The aim of this conversion is to display on a world map the
areas which I have satellite images using a WMS service with MapServer.

What free tool can I use?

Best regards.

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Re: [gdal-dev] GeoTIFF to Shapefile

2011-03-24 Thread Daniele Romagnoli
Hi Emilio,
I think you could use the gdaltindex tool:
http://www.gdal.org/gdaltindex.html

Hope this helps.
Regards,
Daniele

2011/3/24 Emilio de Torres Fernández 

> Hello,
>
> I have GeoTIFF files and need to get a shapefile with the contour of
> each one. The aim of this conversion is to display on a world map the
> areas which I have satellite images using a WMS service with MapServer.
>
> What free tool can I use?
>
> Best regards.
>
> ___
> gdal-dev mailing list
> gdal-dev@lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>



-- 
---
Ing. Daniele Romagnoli
GeoSolutions S.A.S.
Software Engineer

Via Poggio alle Viti 1187
55054  Massarosa (LU)
Italy

phone: +39 0584 962313
fax:  +39 0584 962313
mob:   +39 328 0559267

http://www.geo-solutions.it
http://geo-solutions.blogspot.com/
http://www.youtube.com/user/GeoSolutionsIT
http://it.linkedin.com/in/danieleromagnoli


---
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[gdal-dev] accessing zip files by URL

2011-03-24 Thread Joaquim Luis

Hi,

How do we access to a compressed files by URL? We can do that, can't we?

As an example I try this (on Windows)

gdalinfo 
/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip
ERROR 4: 
`/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip' 
does not exist in the file system,

and is not recognised as a supported dataset name.

and this

gdalinfo 
/vsizip//http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip


but the error message is similar.

The idea is to fetch the data directly into GMT, but first I need to 
understand well how it works.


Thanks

Joaquim Luis
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Chaitanya kumar CH
Joaguim,

I think /vsizip/vsicurl/http://path.to/the/file.zip works.

You have to initialize the zip file and remote file handlers using
VSIInstallCurlFileHandler() and VSIInstallZipFileHandler()

Refer: http://trac.osgeo.org/gdal/wiki/UserDocs/ReadInZip

On Thu, Mar 24, 2011 at 8:48 PM, Joaquim Luis  wrote:

> Hi,
>
> How do we access to a compressed files by URL? We can do that, can't we?
>
> As an example I try this (on Windows)
>
> gdalinfo /vsizip/C:\
> http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip
> ERROR 4: `/vsizip/C:\
> http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip'
> does not exist in the file system,
> and is not recognised as a supported dataset name.
>
> and this
>
> gdalinfo /vsizip//
> http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip
>
> but the error message is similar.
>
> The idea is to fetch the data directly into GMT, but first I need to
> understand well how it works.
>
> Thanks
>
> Joaquim Luis
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>



-- 
Best regards,
Chaitanya kumar CH.
/tʃaɪθənjə/ /kʊmɑr/
+91-9494447584
17.2416N 80.1426E
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Even Rouault
Joaquim,

The correct syntax would be :

gdalinfo 
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip/W020N90.DEM

or just :

gdalinfo 
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip

because the zip file only contains one single file (W020N90.DEM)

... But the W020N90.DEM inside the zip file isn't directly recognized by GDAL 
(even if you download it and unzip the file). It's just a RAW file, that neads 
an header to tell the dimension, georeferencing, datatype etc, so the above 
won't directly work.

You can for example create a VRT that refers to the raw file :


  -20, 8.3338e-03,  0,  90,  0, 
-8.3338e-03
  
-
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip
MSB
  


I've deduced this VRT from the 
http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.hdr.zip file that 
sits next to the .dem.zip file.

It's a shame that they didn't put the .hdr and the .dem file inside the same 
zip. It would have they been possible to open it directly...

With the SRTM3 in HGT format, you can directly do :

gdalinfo 
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Africa/N00E006.hgt.zip

Best regards,

Even

> Hi,
> 
> How do we access to a compressed files by URL? We can do that, can't we?
> 
> As an example I try this (on Windows)
> 
> gdalinfo
> /vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.de
> m.zip ERROR 4:
> `/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.d
> em.zip' does not exist in the file system,
> and is not recognised as a supported dataset name.
> 
> and this
> 
> gdalinfo
> /vsizip//http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.
> zip
> 
> but the error message is similar.
> 
> The idea is to fetch the data directly into GMT, but first I need to
> understand well how it works.
> 
> Thanks
> 
> Joaquim Luis
> ___
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> gdal-dev@lists.osgeo.org
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Even Rouault
Le jeudi 24 mars 2011 18:30:57, Chaitanya kumar CH a écrit :
> Joaguim,
> 
> I think /vsizip/vsicurl/http://path.to/the/file.zip works.
> 
> You have to initialize the zip file and remote file handlers using
> VSIInstallCurlFileHandler() and VSIInstallZipFileHandler()

Actually, they are automagically called when needed (i.e. when the first access 
to the VSI Virtual File API is done), so no need to explicitely call them.

> 
> Refer: http://trac.osgeo.org/gdal/wiki/UserDocs/ReadInZip
> 
> On Thu, Mar 24, 2011 at 8:48 PM, Joaquim Luis  wrote:
> > Hi,
> > 
> > How do we access to a compressed files by URL? We can do that, can't we?
> > 
> > As an example I try this (on Windows)
> > 
> > gdalinfo /vsizip/C:\
> > http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip
> > ERROR 4: `/vsizip/C:\
> > http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip'
> > does not exist in the file system,
> > and is not recognised as a supported dataset name.
> > 
> > and this
> > 
> > gdalinfo /vsizip//
> > http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip
> > 
> > but the error message is similar.
> > 
> > The idea is to fetch the data directly into GMT, but first I need to
> > understand well how it works.
> > 
> > Thanks
> > 
> > Joaquim Luis
> > ___
> > gdal-dev mailing list
> > gdal-dev@lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/gdal-dev
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Joaquim Luis

Even, Chaitanya

Thanks for hint.

I did read the http://trac.osgeo.org/gdal/wiki/UserDocs/ReadInZip but it 
hasn't any mention to the need of using "vsicurl"


I was about to do the tests you did, so thank you also for that.
The point here is not to read that file in particular. I just wanted to 
use one as example and one that is not a *.tar.gz that the docs say it 
won't work.
Ok, I have enough information to make it possible to read some 
compressed files sitting somewhere in the web and have the data land 
directly in the internals of GMT.


Thanks

Joaquim


Joaquim,

The correct syntax would be :

gdalinfo
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip/W020N90.DEM

or just :

gdalinfo
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip

because the zip file only contains one single file (W020N90.DEM)

... But the W020N90.DEM inside the zip file isn't directly recognized by GDAL
(even if you download it and unzip the file). It's just a RAW file, that neads
an header to tell the dimension, georeferencing, datatype etc, so the above
won't directly work.

You can for example create a VRT that refers to the raw file :


   -20, 8.3338e-03,  0,  90,  0,
-8.3338e-03
   
 -
 /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.zip
 MSB
   


I've deduced this VRT from the
http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.hdr.zip file that
sits next to the .dem.zip file.

It's a shame that they didn't put the .hdr and the .dem file inside the same
zip. It would have they been possible to open it directly...

With the SRTM3 in HGT format, you can directly do :

gdalinfo
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Africa/N00E006.hgt.zip

Best regards,

Even


Hi,

How do we access to a compressed files by URL? We can do that, can't we?

As an example I try this (on Windows)

gdalinfo
/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.de
m.zip ERROR 4:
`/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.d
em.zip' does not exist in the file system,
and is not recognised as a supported dataset name.

and this

gdalinfo
/vsizip//http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.
zip

but the error message is similar.

The idea is to fetch the data directly into GMT, but first I need to
understand well how it works.

Thanks

Joaquim Luis
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Even Rouault
Le jeudi 24 mars 2011 19:03:57, Joaquim Luis a écrit :
> Even, Chaitanya
> 
> Thanks for hint.
> 
> I did read the http://trac.osgeo.org/gdal/wiki/UserDocs/ReadInZip but it
> hasn't any mention to the need of using "vsicurl"

Yes I am aware that it is lightly documented. I've added recently a few 
pointers though :

- in the GDALOpen() doc : 
http://gdal.org/gdal_8h.html#e97be045eb4701183ad332ffce29745b

which points to :
http://gdal.org/cpl__vsi_8h.html#4f791960f2d86713d16e99e9c0c36258

Which mentions :

"This special file handler can be combined with other virtual filesystems 
handlers, such as /vsizip. For example, 
/vsizip//vsicurl/path/to/remote/file.zip/path/inside/zip"

Perhaps a more didactic page would be needed in the wiki. Any taker :-) ? I 
remind that the wiki is open in writing for everyone with an osgeo id...

> 
> I was about to do the tests you did, so thank you also for that.
> The point here is not to read that file in particular. I just wanted to
> use one as example and one that is not a *.tar.gz that the docs say it
> won't work.

Ah... well actually reading in a .tar or a .tar.gz is now supported ( 
http://gdal.org/cpl__vsi_8h.html#d6dd983338849e7da4eaa88f6458ab64 ). Seems 
that I have changed my mind since. But seeking will still be very slow of 
course (especially if you combine with /vsicurl !). Ok, I'm going to rectify 
the page about that point.

> Ok, I have enough information to make it possible to read some
> compressed files sitting somewhere in the web and have the data land
> directly in the internals of GMT.

> 
> Thanks
> 
> Joaquim
> 
> > Joaquim,
> > 
> > The correct syntax would be :
> > 
> > gdalinfo
> > /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w02
> > 0n90.dem.zip/W020N90.DEM
> > 
> > or just :
> > 
> > gdalinfo
> > /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w02
> > 0n90.dem.zip
> > 
> > because the zip file only contains one single file (W020N90.DEM)
> > 
> > ... But the W020N90.DEM inside the zip file isn't directly recognized by
> > GDAL (even if you download it and unzip the file). It's just a RAW file,
> > that neads an header to tell the dimension, georeferencing, datatype
> > etc, so the above won't directly work.
> > 
> > You can for example create a VRT that refers to the raw file :
> > 
> > 
> > 
> >-20, 8.3338e-03,  0,  90,  0,
> > 
> > -8.3338e-03
> > 
> >
> >
> >  -
> >   > 
> > relativetoVRT="0">/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/
> > SRTM30/w020n90/w020n90.dem.zip
> > 
> >  MSB
> >
> >
> > 
> > 
> > 
> > I've deduced this VRT from the
> > http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.hdr.zip
> > file that sits next to the .dem.zip file.
> > 
> > It's a shame that they didn't put the .hdr and the .dem file inside the
> > same zip. It would have they been possible to open it directly...
> > 
> > With the SRTM3 in HGT format, you can directly do :
> > 
> > gdalinfo
> > /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Africa/N00E0
> > 06.hgt.zip
> > 
> > Best regards,
> > 
> > Even
> > 
> >> Hi,
> >> 
> >> How do we access to a compressed files by URL? We can do that, can't we?
> >> 
> >> As an example I try this (on Windows)
> >> 
> >> gdalinfo
> >> /vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90
> >> .de m.zip ERROR 4:
> >> `/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n9
> >> 0.d em.zip' does not exist in the file system,
> >> and is not recognised as a supported dataset name.
> >> 
> >> and this
> >> 
> >> gdalinfo
> >> /vsizip//http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.d
> >> em. zip
> >> 
> >> but the error message is similar.
> >> 
> >> The idea is to fetch the data directly into GMT, but first I need to
> >> understand well how it works.
> >> 
> >> Thanks
> >> 
> >> Joaquim Luis
> >> ___
> >> gdal-dev mailing list
> >> gdal-dev@lists.osgeo.org
> >> http://lists.osgeo.org/mailman/listinfo/gdal-dev
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Smith, Michael D ERDC-CRREL-NH
Joaquim,

For .tar.gz, you can use /vsitar

Mike


-- 
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US Army Corps of Engineers
Hanover, NH



On 3/24/11  2:03 PM, "Joaquim Luis"  wrote:

> Even, Chaitanya
> 
> Thanks for hint.
> 
> I did read the http://trac.osgeo.org/gdal/wiki/UserDocs/ReadInZip but it
> hasn't any mention to the need of using "vsicurl"
> 
> I was about to do the tests you did, so thank you also for that.
> The point here is not to read that file in particular. I just wanted to
> use one as example and one that is not a *.tar.gz that the docs say it
> won't work.
> Ok, I have enough information to make it possible to read some
> compressed files sitting somewhere in the web and have the data land
> directly in the internals of GMT.
> 
> Thanks
> 
> Joaquim
> 
>> Joaquim,
>> 
>> The correct syntax would be :
>> 
>> gdalinfo
>> /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90
>> .dem.zip/W020N90.DEM
>> 
>> or just :
>> 
>> gdalinfo
>> /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90
>> .dem.zip
>> 
>> because the zip file only contains one single file (W020N90.DEM)
>> 
>> ... But the W020N90.DEM inside the zip file isn't directly recognized by GDAL
>> (even if you download it and unzip the file). It's just a RAW file, that
>> neads
>> an header to tell the dimension, georeferencing, datatype etc, so the above
>> won't directly work.
>> 
>> You can for example create a VRT that refers to the raw file :
>> 
>> 
>>-20, 8.3338e-03,  0,  90,  0,
>> -8.3338e-03
>>
>>  -
>>  > relativetoVRT="0">/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM
>> 30/w020n90/w020n90.dem.zip
>>  MSB
>>
>> 
>> 
>> I've deduced this VRT from the
>> http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.hdr.zip file
>> that
>> sits next to the .dem.zip file.
>> 
>> It's a shame that they didn't put the .hdr and the .dem file inside the same
>> zip. It would have they been possible to open it directly...
>> 
>> With the SRTM3 in HGT format, you can directly do :
>> 
>> gdalinfo
>> /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Africa/N00E006.h
>> gt.zip
>> 
>> Best regards,
>> 
>> Even
>> 
>>> Hi,
>>> 
>>> How do we access to a compressed files by URL? We can do that, can't we?
>>> 
>>> As an example I try this (on Windows)
>>> 
>>> gdalinfo
>>> /vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.de
>>> m.zip ERROR 4:
>>> `/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.d
>>> em.zip' does not exist in the file system,
>>> and is not recognised as a supported dataset name.
>>> 
>>> and this
>>> 
>>> gdalinfo
>>> /vsizip//http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.dem.
>>> zip
>>> 
>>> but the error message is similar.
>>> 
>>> The idea is to fetch the data directly into GMT, but first I need to
>>> understand well how it works.
>>> 
>>> Thanks
>>> 
>>> Joaquim Luis
>>> ___
>>> gdal-dev mailing list
>>> gdal-dev@lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>> 
> 
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Joaquim Luis

Great, thanks

Joaquim


Le jeudi 24 mars 2011 19:03:57, Joaquim Luis a écrit :

Even, Chaitanya

Thanks for hint.

I did read the http://trac.osgeo.org/gdal/wiki/UserDocs/ReadInZip but it
hasn't any mention to the need of using "vsicurl"

Yes I am aware that it is lightly documented. I've added recently a few
pointers though :

- in the GDALOpen() doc :
http://gdal.org/gdal_8h.html#e97be045eb4701183ad332ffce29745b

which points to :
http://gdal.org/cpl__vsi_8h.html#4f791960f2d86713d16e99e9c0c36258

Which mentions :

"This special file handler can be combined with other virtual filesystems
handlers, such as /vsizip. For example,
/vsizip//vsicurl/path/to/remote/file.zip/path/inside/zip"

Perhaps a more didactic page would be needed in the wiki. Any taker :-) ? I
remind that the wiki is open in writing for everyone with an osgeo id...


I was about to do the tests you did, so thank you also for that.
The point here is not to read that file in particular. I just wanted to
use one as example and one that is not a *.tar.gz that the docs say it
won't work.

Ah... well actually reading in a .tar or a .tar.gz is now supported (
http://gdal.org/cpl__vsi_8h.html#d6dd983338849e7da4eaa88f6458ab64 ). Seems
that I have changed my mind since. But seeking will still be very slow of
course (especially if you combine with /vsicurl !). Ok, I'm going to rectify
the page about that point.


Ok, I have enough information to make it possible to read some
compressed files sitting somewhere in the web and have the data land
directly in the internals of GMT.
Thanks

Joaquim


Joaquim,

The correct syntax would be :

gdalinfo
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w02
0n90.dem.zip/W020N90.DEM

or just :

gdalinfo
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w02
0n90.dem.zip

because the zip file only contains one single file (W020N90.DEM)

... But the W020N90.DEM inside the zip file isn't directly recognized by
GDAL (even if you download it and unzip the file). It's just a RAW file,
that neads an header to tell the dimension, georeferencing, datatype
etc, so the above won't directly work.

You can for example create a VRT that refers to the raw file :



-20, 8.3338e-03,  0,  90,  0,

-8.3338e-03



  -
  /vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/
SRTM30/w020n90/w020n90.dem.zip

  MSB





I've deduced this VRT from the
http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.hdr.zip
file that sits next to the .dem.zip file.

It's a shame that they didn't put the .hdr and the .dem file inside the
same zip. It would have they been possible to open it directly...

With the SRTM3 in HGT format, you can directly do :

gdalinfo
/vsizip/vsicurl/http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Africa/N00E0
06.hgt.zip

Best regards,

Even


Hi,

How do we access to a compressed files by URL? We can do that, can't we?

As an example I try this (on Windows)

gdalinfo
/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90
.de m.zip ERROR 4:
`/vsizip/C:\http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n9
0.d em.zip' does not exist in the file system,
and is not recognised as a supported dataset name.

and this

gdalinfo
/vsizip//http://dds.cr.usgs.gov/srtm/version2_1/SRTM30/w020n90/w020n90.d
em. zip

but the error message is similar.

The idea is to fetch the data directly into GMT, but first I need to
understand well how it works.

Thanks

Joaquim Luis
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Re: [gdal-dev] Integer overflow issue in ogr2ogr

2011-03-24 Thread Even Rouault
Le jeudi 24 mars 2011 00:33:44, Dan Putler a écrit :
> All,
> 
> I'm working with the topological faces from the 2010 Tiger shapefile
> data. Some of the faces are huge in Alaska (over 2147483647 meters^2,
> which exceeds the size of a signed 32 bit integer). In the block face
> attribute table the area of each face is given. When I process a file
> with these large areas with ogr2ogr, the resulting attribute table has
> area values that have been converted from the large value to -2147483648
> (the largest, in absolute value, possible negative value of a 32 bit
> signed integer). I'm using GDAL 1.7.3 on Ubuntu 10.4 64 bit which I
> obtained from the Ubuntu GIS repository (1.8.0 has not made it to the
> Ubuntu GIS repository yet). My question really is whether there is a
> work around, say processing the file beforehand in a way that converts
> the large integers to double precision values.

Yes this is a well known problem that has been recorded in multiple tickets... 
A possible solution would be the adoption of a 64bit integer type. There's a 
pending (not yet implemented) RFC to deal about that : 
http://trac.osgeo.org/gdal/wiki/rfc31_ogr_64

A possible workaround would be to edit the header of the DBF file to alter the 
field definition and set a non 0 value for the number of decimals. In which 
case 
OGR will recognize it as a double value (but you could potential have 
precision loss).

> 
> Dan
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Joaquim Luis



Ah... well actually reading in a .tar or a .tar.gz is now supported (
http://gdal.org/cpl__vsi_8h.html#d6dd983338849e7da4eaa88f6458ab64 ). Seems
that I have changed my mind since. But seeking will still be very slow of
course (especially if you combine with /vsicurl !). Ok, I'm going to rectify
the page about that point.


Even,

Still one further point on this matter. This works fine with the 
promised slowness (fair enough)


gdalinfo 
/vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz/W020N90.DEM


but the file name is case dependent. I mean, this doesn't work

gdalinfo 
/vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz/w020n90.dem


I'm not sure what is the right thing to do here but as a Win (and 
occasional Mac or Linus)  user I guess that I was expecting no case 
dependency.


Joaquim
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Even Rouault
> 
> Even,
> 
> Still one further point on this matter. This works fine with the
> promised slowness (fair enough)
> 
> gdalinfo
> /vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.t
> ar.gz/W020N90.DEM
> 
> but the file name is case dependent. I mean, this doesn't work
> 
> gdalinfo
> /vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.t
> ar.gz/w020n90.dem
> 
> I'm not sure what is the right thing to do here but as a Win (and
> occasional Mac or Linus)  user I guess that I was expecting no case
> dependency.

GDAL's behaviour with the case sensitivity in a virtual file path is completely 
OS independant.

Actually filenames in archives are case sensitive. I have just made a .tar.gz 
with 2 filenames that only differ by their case :

$ tar tvzf aa.tar.gz
-rw-r--r-- even/even 2 2011-03-24 23:54 Aa
-rw-r--r-- even/even 3 2011-03-24 23:54 aa

And the same with a zip file :

$ unzip -l aa.zip 
Archive:  aa.zip
  Length  DateTimeName
-  -- -   
2  2011-03-24 23:54   Aa
3  2011-03-24 23:54   aa
- ---
5 2 files

Admitedly a windows user will not be very happy when he uncompresses those 
archives in a "real" filesystem ;-)

I will also note that URLs are also case sensitive.

http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz is a valid 
URL, but http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gZ is 
not

So I'm not sure that there's really a point in making the lookup of filenames 
inside the archive case insensitive.

> 
> Joaquim
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Joaquim Luis



GDAL can not fix the fact that:

   http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz/w020n90.dem

is a 404.

-- Chris



Sure, the browsers are not yet GDAL compliant and cannot see directly 
inside compressed files.

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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Joaquim Luis
I understand all that and even though I'm a win user I always try to be 
very careful with case names (basically, I avoid upper cases). But while 
it is easy to see the case of the real file (I know that urls are case 
sensitive) it's not so easy so clear to know what's inside a compressed 
file on the internet because if you know it it means one already have it 
in the local file system.
Since is up to gdal to read the contents of the compressed file and get 
its data (NOT the file itself) it seams to me that there would be no 
danger in being case insensitive.
But this is really a minor point (once you know why it didn't work on 
the first time), I know.


Joaquim


Even,

Still one further point on this matter. This works fine with the
promised slowness (fair enough)

gdalinfo
/vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.t
ar.gz/W020N90.DEM

but the file name is case dependent. I mean, this doesn't work

gdalinfo
/vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.t
ar.gz/w020n90.dem

I'm not sure what is the right thing to do here but as a Win (and
occasional Mac or Linus)  user I guess that I was expecting no case
dependency.

GDAL's behaviour with the case sensitivity in a virtual file path is completely
OS independant.

Actually filenames in archives are case sensitive. I have just made a .tar.gz
with 2 filenames that only differ by their case :

$ tar tvzf aa.tar.gz
-rw-r--r-- even/even 2 2011-03-24 23:54 Aa
-rw-r--r-- even/even 3 2011-03-24 23:54 aa

And the same with a zip file :

$ unzip -l aa.zip
Archive:  aa.zip
   Length  DateTimeName
-  -- -   
 2  2011-03-24 23:54   Aa
 3  2011-03-24 23:54   aa
- ---
 5 2 files

Admitedly a windows user will not be very happy when he uncompresses those
archives in a "real" filesystem ;-)

I will also note that URLs are also case sensitive.

http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz is a valid
URL, but http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gZ is
not

So I'm not sure that there's really a point in making the lookup of filenames
inside the archive case insensitive.


Joaquim




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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread Even Rouault
Le vendredi 25 mars 2011 00:37:38, Joaquim Luis a écrit :
> I understand all that and even though I'm a win user I always try to be
> very careful with case names (basically, I avoid upper cases). But while
> it is easy to see the case of the real file (I know that urls are case
> sensitive) it's not so easy so clear to know what's inside a compressed
> file on the internet because if you know it it means one already have it
> in the local file system.

Actually you don't need to download the file to know its content.

Just a bit of C/Python/Java/C#/Perl magic.

For example, with python :

from osgeo import gdal
print 
gdal.ReadDir('/vsizip/vsicurl/http://www.aprsworld.net/gisdata/world/world.zip')

Answer : ['world.dbf', 'world.shp', 'world.shx']

(For a .tar.gz, unfortunately getting the list of files means in practice that 
GDAL will have to download the whole .tar.gz)
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Re: [gdal-dev] accessing zip files by URL

2011-03-24 Thread christopher.schmidt

On Mar 24, 2011, at 6:47 PM, ext Joaquim Luis wrote:

> 
>> Ah... well actually reading in a .tar or a .tar.gz is now supported (
>> http://gdal.org/cpl__vsi_8h.html#d6dd983338849e7da4eaa88f6458ab64 ). Seems
>> that I have changed my mind since. But seeking will still be very slow of
>> course (especially if you combine with /vsicurl !). Ok, I'm going to rectify
>> the page about that point.
> 
> Even,
> 
> Still one further point on this matter. This works fine with the promised 
> slowness (fair enough)
> 
> gdalinfo 
> /vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz/W020N90.DEM
> 
> but the file name is case dependent. I mean, this doesn't work
> 
> gdalinfo 
> /vsitar/vsicurl/http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz/w020n90.dem
> 
> I'm not sure what is the right thing to do here but as a Win (and occasional 
> Mac or Linus)  user I guess that I was expecting no case dependency.

"Tough luck"? The world is case dependent. Filenames on Linux (and sometimes on 
Mac) are case
dependent, and HTTP servers are usually case dependent. 

GDAL can not fix the fact that:

  http://edcftp.cr.usgs.gov/pub/data/gtopo30/global/w020n90.tar.gz/w020n90.dem

is a 404.

-- Chris

> Joaquim
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