James Cobban wrote:

> I am just astonished that I have to set such extreme quality values to
> get a reasonable sized file.

Very likely the TIFF files are 1 bit per pixel (only black or white,
with no gray).  JPEG supports a minimum of 8 bits per pixel, so right
away, with equivalently efficient compression, the JPEGs are going to be
8 times as large.

JPEG is also most efficient when there aren't a lot of high frequency
components (sharp transitions in color or shade), and this is the
opposite of what you have with a page full of text.

If you really need these to be JPEG, you can reduce them to, say, half
the original size, and still get quite acceptable quality.  The lost
resolution will be mitigated somewhat by the increased bit depth.  This
would also make the images a more reasonable size for viewing on a
computer monitor.

But if you want to retain as much of the original information as
possible, leave them as TIFF or convert to another format that supports
losslessly compressed 1-bit images (GIF, for example).

- Ernie                                  http://home.comcast.net/~erniew

Gimp-user mailing list

Reply via email to