TIFF encoder problems

[Unruh, Jay-2]

Dear ImageJ community,

I noticed that the TIFF encoder for ImageJ defines fieldtype for the image height parameter as short.  I have been working with some long line scan data sets and reading them in as tiff.  Unfortunately, when I resave the data, the height parameter gets trucated to the first word of the actual height.  The data is still there, but upon rereading the data, it is truncated.  Does anyone know if this can be fixed or if there is another tiff encoder plugin that I can use?  For now I have simply changed the fieldType to 4 (long) in TiffEncoder.java and recompiled ImageJ.  Is there a problem with doing this?

Jay Unruh
Research Specialist
Stowers Institute for Medical Research

[Wayne Rasband]

> Dear ImageJ community,
>
> I noticed that the TIFF encoder for ImageJ defines fieldtype for the
> image height parameter as short.  I have been working with some long
> line scan data sets and reading them in as tiff.  Unfortunately, when
> I resave the data, the height parameter gets trucated to the first
> word of the actual height.  The data is still there, but upon
> rereading the data, it is truncated.  Does anyone know if this can be
> fixed or if there is another tiff encoder plugin that I can use?  For
> now I have simply changed the fieldType to 4 (long) in
> TiffEncoder.java and recompiled ImageJ.  Is there a problem with doing
> this?

The TiffEncoder in the ImageJ 1.42o daily build sets the field type to
4 (32-bit) for the ImageWidth and ImageLength tags. This should not be
a problem since the TIFF standard allows these tags to use either SHORT
(16-bit) or LONG (32-bit) field types. By using 32-bits, ImageJ can now
correctly save images that have a width or height greater than 65,535.

-wayne