Problem opening TIFF image in ImageJ

[Mark Ruberto]

Hi All,

We have a series of Fuji Xerox Printers (Docu-Centre III-6500 and Docu-Centre IV-3370) that users are scanning images from.

These files aren't accessible in ImageJ.

ImageJ errors out with the error that the compression type isn't supported.

Here is one of the files that was scanned from the scanner: http://dl.dropbox.com/u/12900912/img-704130656-0001.tif

Could someone tell me what is going on or what type of compression in a TIFF is supported.
The only compression supported by our MFD is JPEG or no compression - both error out with the same error.

Kind Regards and thanks,
Mark.

[dscho]

Hi Mark,

On Tue, 5 Jul 2011, Mark Ruberto wrote:

> We have a series of Fuji Xerox Printers (Docu-Centre III-6500 and
> Docu-Centre IV-3370) that users are scanning images from.
>
> These files aren't accessible in ImageJ.

The problem is not so much the compression but that your images are
bi-level (i.e. half-toning via pixels that are either pitch black or pure
white).

(I found out by using the Bio-Formats Importer which told me:
loci.formats.FormatException: Sorry, CCITT T.4 bi-level encoding (Group 3
Fax) compression mode is not supported)

Now, it should not be a very big problem for a capable programmer to
support this compression, but that's only where the trouble starts: if you
load the file into, say, GIMP, and zoom in so you see individual pixels,
you see funny Moire patterns. That is because halftoning simulates
grayscales by scattering black pixels about a white canvas (see e.g.
http://fiji.sc/Dithering).

But that means that all your analyses will be hard to impossible. For
example, simple thresholding will catch all the white _pixels_.

Better select "grayscale image" at the scanner. With that, it is much
more likely that the compression is supported by ImageJ, either. (I am
frequently opening scans from a Xerox WorkCentre 6220 without problems.)

Ciao,
Johannes