Re: compression strategy
- Subject: Re: [iris-photos] compression strategy
- From: Cathy <email@example.com>
- Date: Mon, 28 Jun 2004 13:15:52 -0700
In a message dated
6/28/2004 10:25:45 AM Central Daylight Time, firstname.lastname@example.org
If you are resizing by dimensions or dpi it wouldn't be a factor. If
you are using a RESIZE command it possibly could be taking all the
guess work out of jpg compression. Each time you use the SAVE command
to jpg format it will use the default compression index. Use the SAVE
AS command and you should see the scale.(probably reflecting the
default setting.) Even at the 100 setting(no compression) there is
always some loss when resaved to jpg format. resaving with compression
increases the loss. For example the JI pollenating jpg at a 50 index
resaved at a 50 index would result in a 26% loss in detail. Small
losses in detail are not that noticeable on the computer but do appear
in printing. Editing photos for printing is usually done in TIFF
format which is LARGE file but lossless but no compression. Jpg(
JPEG-Joint Photograph Exchange Graphics?) was done to make small files
for internet transfer.
compression formulas don't produce linear results. The scale you see as
you save an image to JPG is a quality index scale.
I do not see a scale identified as such when using PhotoStudio to
Dunno. specific size dimensions - no; specific size dpi - no but file
size - - probably. I will send you a small jpg compression checker from
www.mediachance.com. It is helpfull to know how compressed an image is
before you start to work on it.
On the other hand, when scannin' images to a specific size I am given
percentage reduction information for the scan being sized. Is this the
same, or similar to, the scale to which you refer?
Ah Hah! Now yu're getting personal
Prechate the other info and response.
FWIW: Fun With Internet Whackos <laughin'>
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