[Xastir] Compression algorithm problem with DRGs

[Derrick J Brashear]

You should reply to the list, rather than me.

On Sun, 28 Mar 2004, Josh Keller wrote:

> Yes, I did install libproj before compiling geotiff, and as I said, some of
> the DRGs load just fine, including trimming the border off.
>
> $ tiffinfo o44123C4.tif
> TIFFReadDirectory: Warning, o44123C4.tif: unknown field with tag 33550
> (0x830e) encountered.
> TIFFReadDirectory: Warning, o44123C4.tif: unknown field with tag 33922
> (0x8482) encountered.
> TIFF Directory at offset 0x8
>   Subfile Type: (0 = 0x0)
>   Image Width: 4288 Image Length: 5838
>   Resolution: 0.125, 0.125 (unitless)
>   Bits/Sample: 8
>   Compression Scheme: PackBits
>   Photometric Interpretation: palette color (RGB from colormap)
>   Samples/Pixel: 1
>   Rows/Strip: 2
>   Planar Configuration: single image plane
>   Color Map: (present)
>   Software: Arc/Info

geotifcp can recompress with another scheme. if you compiled libtiff with
zip support, i suggest the following for DRGs:
geotifcp -c zip:1 old.tif new.tif
(and then rename new.tif to old.tif so the fgd files will still work)

listgeo will tell you if the geotiff tags are any good.