LZW Compression

[Jay Gourley]

Why does MS Office Document Imaging 2003 offer LZW compression? Is it
supposed to work? When I open a .tif file with no compression and then save
as by indicating LZW compression, Document Imaging saves the document
without any compression. What's going on?

 

[Bob Buckland ?:-\)]

Hi Jay,

Yes, the LZW compression does work, but what you
see as a result in file size can depend on the
content of the graphic, including the source and
bit rate used.

For example, if I create a 1000 pxl by 1000 pxl
graphic in a single solid color at 100 ppi and
save it uncompressed it takes 2.8mb. Same file
saved with LZW compression will yield a file of 108K.
But in a complex graphic (painting or photo) it
can be a no change or even slightly larger file
than the original.

This information may be helpful to you regarding
the LZW compression.
http://www.scantips.com/basics9t.html

You can also choose JPEG compression in MS Office
Document Imaging for TIF files.

======
Why does MS Office Document Imaging 2003 offer LZW compression? Is it
supposed to work? When I open a .tif file with no compression and then save
as by indicating LZW compression, Document Imaging saves the document
without any compression. What's going on?>>
--
Let us know if this helped you,

Bob Buckland ?
MS Office System Products MVP

*Courtesy is not expensive and can pay big dividends*

Office 2003 Editions explained
http://www.microsoft.com/uk/office/editions.mspx

 

[Jay Somerset]

Why does MS Office Document Imaging 2003 offer LZW compression? Is it
supposed to work? When I open a .tif file with no compression and then save
as by indicating LZW compression, Document Imaging saves the document
without any compression. What's going on?

I suspect LZW won't compress a tif file. Very few lossless compressions
schemes will make much of a dent on that type of file. You are stuck with a
"lossy" method if you want to get any significant compression, line jpeg
(jpg).