Re: LZW compressed tiffs

Posted by Jon Harman on Sep 15, 2005; 11:22pm
URL: http://imagej.273.s1.nabble.com/LZW-compressed-tiffs-tp3704864p3704866.html

Hi,

Thanks for the suggestion.  I've checked it out and it seems to work
well, except for the following:
On very large files it can take a while to write out the png image, but
it is possible to close the image before the writing finishes and in
this case the output is only partial.  You have to watch the ImageJ
status line to verify that the write has finished.  Is there a way to
lock the image from closing before the output routine has finished?

Jon

.Jarek Sacha wrote:

> Jon Harman wrote:
>
>> In looking for lossless compression for my large image files, I
>> started using LZW tiffs. (are there better formats?) I found that
>> different programs produce very different output files using this and
>> sometimes ImageJ would fail to read the output.  For instance
>> paintshop pro sometimes produces a file that can't be read.  
>> Photoshop seems much better.  Irfanview  produces files that
>> sometimes can't be read, and additionally aren't much compressed.  So
>> this format seems to be a can of worms.
>
>
> PNG format has good lossless compression. ImageJ can read it with no
> problems (at least I never seen any), however, to write PNG you will
> need a plugin like one available at:
> http://ij-plugins.sourceforge.net/plugins/imageio/index.html
> That plugin bundle also have plugins that can correctly read tiled
> ("out of order") TIFF images. Current release version does not support
> some of the newer PhotoShop LZW variants, and cannot write compressed
> images. The version 2.0 (not yet released but available through CVS),
> can read PhotoShop LZW, and will be able to write LZW compressed TIFF
> images. It will also support lossless JPEG2000 that can compress
> better than LZW TIFF or PNG. If you need more info on that or will
> like to help with new plugins (implementing or testing), let me know.
>
> Jarek
>
>