gdal and jgp issues

[Frank Broniewski]

Hello list

I have a problem which is only little related with mapserver, but maybe
someone can help me.

I have orthofotos in tif-format with a worldfile (tfw) and i want them
for transportation reasons (a presentation) to be converted from
tif-format to jpeg-format. I used irfanview to batch-convert all
tif-files into jpg-format. After that, I renamed all tfw-files to .jgw.

After doing so, I tested if everything went well. I added the new
created jpg-files into Arc and they fitted well on to their right place
in the world.
But I want to use the files with mapserver, so I made an additional test
with gdalinfo. But there seems to be a problem, because gdalinfo returns
only the pixeldimensions and not the real world coordinates. I renamed
the .jgw into .wld but this didn't help me either. The converted jpgs
have the same dimension as the tif-images, from whose I get the expected
dimension by the way.

Has anyone an idea whats going wrong?



for clarification reasons, here is the gdalinfo output:

c:\karten\cds\cadastre\ortho_lowres>gdalinfo 2001-0048-0107-50.jpg
Driver: JPEG/JPEG JFIF
Size is 2000, 2000
Coordinate System is `'
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 2000.0)
Upper Right ( 2000.0,    0.0)
Lower Right ( 2000.0, 2000.0)
Center      ( 1000.0, 1000.0)
Band 1 Block=2000x1 Type=Byte, ColorInterp=Red
  Min=0.000/0, Max=255.000/0
Band 2 Block=2000x1 Type=Byte, ColorInterp=Green
  Min=0.000/0, Max=255.000/0
Band 3 Block=2000x1 Type=Byte, ColorInterp=Blue
  Min=0.000/0, Max=255.000/0


And here is the output from the tif-file:

c:\karten\cds\cadastre\ortho>gdalinfo 2001-0048-0107-50.tif
Driver: GTiff/GeoTIFF
Size is 2000, 2000
Coordinate System is `'
Origin = (48000.000000,107000.000000)
Pixel Size = (0.500000,-0.500000)
Corner Coordinates:
Upper Left  (   48000.000,  107000.000)
Lower Left  (   48000.000,  106000.000)
Upper Right (   49000.000,  107000.000)
Lower Right (   49000.000,  106000.000)
Center      (   48500.000,  106500.000)
Band 1 Block=2000x1 Type=Byte, ColorInterp=Red
  Min=0.000/0, Max=255.000/0
Band 2 Block=2000x1 Type=Byte, ColorInterp=Green
  Min=0.000/0, Max=255.000/0
Band 3 Block=2000x1 Type=Byte, ColorInterp=Blue
  Min=0.000/0, Max=255.000/0
                                                      
Frank Broniewski
Musée National d'Histoire et d'Art
Section Préhistoire / Projet EPC
    Tél: +352 260 281-21
241, Rue de Luxembourg
L-8077 Bertrange