----- Original Message -----
Sent: Sunday, November 06, 2005 2:47
PM
Subject: [iris-photos] file size
There are 4 main
techniques to control file size.
The first is
cropping. This eliminates unneeded background. There is no effect on image
quality.
The second is
setting pixels (dots) per inch (dpi). As was just pointed out,
monitors show either 72 or 96. What is shown on the monitor when the dpi is
300 or 600 depends on the software being used. Some software shows the
entire image at the monitor's dpi so the image is greater than the
size of the monitor. This is usually hated by the person who received
the image. Other software resizes the image so the image is just full
screen. There can be image quality impacts of the resizing.
The third is
image size. In general, image quality decreases as image size
decreases.
The fourth is
compression. jpg is a compressed format. The jpg software can adjust
the compression ratio. The greater the compression ratio the less accurate
the color and detail. Considering the lack of color accuracy in the whole
process of obtaining and viewing an image, compressing an iris image to a
file size about 50K will be totally acceptable to most of this group. Anyone
who needs greater quality can do so off line.
I have attached
a photo of a Peter Jackson Louisiana iris seedling to show what is
possible in terms of quality and size in a 63K file.
Fortunately I
have DSL and Windows XP so all of this discussion of file size has
little significance to me. However I do remember the bad old days of dialup
when I was quick to remind senders of large files to be more considerate in
the future. Personally I think a restriction of 50K is too restrictive. When
I was on a 44k dialup, I felt the file size limit should have been 300K. Any
comments from the dialupers on what they feel is a reasonable limit. A
change in the recommended file size may be a reasonable compromise.
Harold Peters
Beautiful View Iris Garden
2048 Hickok Road
El Dorado Hills, CA 95762
