3Putt from CoastalSouth Carolina wrote:
"Joan F (MI)" wrote in message
...
Duh! You leave the original as is and save the reduced size for posting
as
a separate file.

IMO, we should try for a consensus on file size, not image size. You can
set the image viewer (or newsreader) to reduce the displayed image to
fit your screen if you don;'tr want to scroll around to see the whole image.

The originals from my camera are 2560 x 1920 px, far
larger than will fit on any average user's monitor and the file sizes are
as
large as 2 MB, no one wants to download a bunch of files that large. The
only time you need all that information is if you are making very large
prints.

I tried to say something similar, but was accused of criticizing.
Somewhere along similar lines a question was raised about posting
(uploading) to these photo groups using a dpi of 300. Then the objection
was that monitors only display at a much lesser dpi. So all this
mumble-jumble only leads to more confusion. But I agree. I don't or
wouldn't post an original, unedited photo straight from the memory card.

Well, that's an esthetic choice, not a technical one. I prefer straight
photography, and don't like to edit photos. Not that I never edit
photos, but I usually do so to achieve a different effect, not to
produce the effect I was aiming for when I took the picture. A holdover
from my film days, I suppose. ;-)

BTW, have you noticed that if you apply certain filters to your image,
you actually increase the JPEG file size? That's because those filters
increase average differences between pixels, and compression relies on
the fact that in any one region of the image you are likely to have lots
of pixels low or even zero average differences.


I
always save off the original to a dvd/cd for future use. Resize and edit
for posting.

I suggest you edit before resizing. Resizing destroys some image
information, which reduces the effectiveness of the editing.


Dial-up, DSL, Cable. Doesn't matter. And how many of us
remember that we have downloaded tons of megabytes that are still sitting in
a file on your computer?


Fact is that most people have cameras that save images as lossless
JPEGs, not bitmaps, and definitely not in RAW format. A 4 megapixel
bitmap image is a great deal larger than 1 or 2 megabytes. (At 24 bits
per pixel, it's about 12MB. The RAW format image would be huge). The
lossless JPEG can be compressed another 50% or more - and many image
viewers will do this by default if you Save the image after displaying
it. (A poor design decision, IMO, but I guess the assumption is that if
you want to Save the image, you've tinkered with it.)

Keep in mind that the display software converts the JPEG to a bitmap,
saves that file in RAM, resizes it to fit the screen if set to do so,
and then sends the image to the video system. If you then Save the
displayed image, the software Saves the image in RAM to the HD,
compressing it first. The default compression is _not_ lossless, so that
the newly saved image is compressed more than the original -- smaller
file size. Actually, it's a quick and dirty way to reduce the image
you've copied from the memory card by about 50% to 70%, and I've often
done this.

BTW, it doesn't matter what dpi the original image is, what matters is
its resolution in pixels. Monitors display in pixels, not dpi. If you
have two monitors with the same resolution, the smaller one will have a
higher dpi than the larger one.

As for the scanner's dpi, that does matter. You will get the best
results if you scan at the scanner's _optical_ resolution, which is
always lower than the advertised "up to" resolution. Higher resolutions
are merely a digital zoom, and digital zoom does not increase the image
information. In fact, poor zoom algorithms will destroy information.

Bottom line: IMO we should try for a consensus on _file_ size. I suggest
200-400KB, or else both dial-up (say 150-300KB) and a broadband sizes
(say 500KB and up.)

HTH

--

Wolf

"Don't believe everything you think." (Maxine)