[Gdal-dev] gdal_translate with -gcp, gdaltindex

Aleksey Naumov naumov at buffalo.edu
Fri Mar 11 17:19:49 EST 2005

Dear Frank and developers,

Thank you for the great work on GDAL. The new 1.2.6 seems to work fine so far 
on my Fedora Core 2. 

I did encounter a couple of quirks lately with using gdal_translate and 

(1) There seems to be a problem with parsing of command arguments to 
gdal_translate when -gcp is used. The following:

gdal_translate -of GTiff -gcp 0 0 100 100 1.bmp 1.tif

just returns Usage: ..., but only when <src_dataset> name starts with a digit, 
like "1.bmp". If input dataset is changed to "a1.bmp" or there is another 
flag after "-gcp 0 0 100 100" then all is fine:

gdal_translate -of GTiff -gcp 0 0 100 100 a1.bmp 1.tif
gdal_translate -of GTiff -gcp 0 0 100 100 -co "TILED=YES" 1.bmp 1.tif

(2) Is there a minimum number of GCPs that can be added to an image? 
"gdal_translate" does not complain when only one GCP is given, however 
running "gdalinfo" on the output shows no GCPs in it. 

Perhaps it does not make sense to add just 1 GCP (since it is not enough to 
set up a transform later)? If so, this should be noted in the documentation, 
and "gdal_translate" should perhaps give a warning.

(3) A minor problem with "gdaltindex". Running:

gdaltindex index.shp *.tif

I get 

ERROR 4: Unable to open index.shp or index.SHP.

However, index.shp is generated and seems to be fine. 

Thank you,

Aleksey Naumov
Department of Geography

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