[lug] Are xcf (gimp) files that much smaller than bmps?

[lug at lug.boulder.co.us]

>>>>> "Michael" == Michael D Hirsch <mhirsch at nubridges.com> writes:

Michael> On Monday 31 March 2003 12:57 pm, Andrew Diederich wrote:
>> I was playing around with a 3mb bmp file, added a layer.  Since you
>> can't save layers in bmps, I guess, I used the gimp native format,
>> xcf.  The xcf file is 480kb, the bmp is 3070kb.
>> 
>> Are xcf files really that much better at compression than windows
>> bitmaps?

Michael> My impression is that windows bmp files are
Michael> uncompressed--certainly the ifle sizes seem to imply that.  And
Michael> that's usually the meaning of "bitmap", anyway.

I accidentally found out that windows does support some forms of bitmap
compression, and the Gimp will create them.  Take the bitmap, switch to
index mode (Ctrl-I) and create an index with a custom palette.  Then do
a Save-As and pick bmp.  Gimp will prompt you to do RLE (Run Length
Encoding) compression on the image.  

At the time I was working a truly horrendous wordpro doc with 100 or so
embedded bitmaps (screen shots).   Creating indexed, RLE bitmaps reduced
the size of the document by 90%.

[...]

enjoy,

-jeremy

-- 
========================================================================
 Jeremy Hinegardner                              jeremy at hinegardner.org