large tiff files being cut after processing

[magick]

ImageMagick requires gigabytes of temporary disk space to process large files. If the temporary space is not available its possible to the output image will be incomplete or corrupt. If you post a URL to your image we will try the conversion and report back success or failure.

[magick]

We converted your image without complaint:

• convert glsds_orig_nogeo.tif -modulate 800 glsds.tif
  convert glsds.tif -resize 10% glsds.png
  display glsds.png

The result did not exhibit the black area you mentioned. We're using ImageMagick 6.2.8-0 on a Fedora Core 5 box.

[magick]

Recent versions of ImageMagick and the TIFF delegate library may resolve your problem. Copious amounts of free disk space may help as well. Otherwise you may need to try a different solution.