2002.03.22 14:28 "TIFF image tiles from the UK Ordnance Survey Errors out.", by Roger Bedell

Please forgive me if this is a duplicate post, I had a little trouble subscribing to the TIFF list (my fault).

I am trying to load a TIFF image tiles from the UK Ordnance Survey. It errors out with a variety of warnings, the most critical of which seems to be:

Incorrect count for field "RowsPerStrip" (0, expecting 1); tag ignored

And

Incorrect count for field "StripOffsets"(2000, expecting 1); tag ignored

After this it crashes hard.

Can anyone help me? I am using v3.5.7 of libtiff. I've never had a problem before.

You can download the test file I've been using from:

http://sylvanmaps.com/temp/Tq06.zip

Here is some more information from my customer who is trying to use these files:

It's a standard Ordnance Survey 20km x 20km image tile. I tried another one and that didn't work either. The Ordnance Survey is the UK government national mapping agency.

"1:50,000 Scale Colour Raster data is the definitive raster dataset providing national coverage of Great Britain. It is comprised of 812 20km by 20km tiles, offering seamless coverage of the entire country.

The 1:50,000 Scale Colour Raster data product mirrors the popular LandrangerR map series, Britain's most popular map series. It can provide the ideal mapping backdrop upon which to overlay business information."

According to their technical spec the file I sent you was "TIFFT Palette 8 bit (256 colours) uncompressed". They charge a fee for these files, so I don't think there's anywhere the libtiff developers can get them from.

Got all this from http://www.ordsvy.gov.uk/ choosing 1:50,000 scale raster image from the dropdown. There is a sample you can download from their website ("sample data" link). I just tried to download it but it didn't succeed

Thanks for looking into it, I suppose now we wait to see whether anyone responds on the libtiff list,

Thanks!!

Roger Bedell

roger@sylvanmaps.com