given file size limit, optimize jpeg level and resolution?

One of the classified ads site I use has a file size limit of 200KB on the
photo and it has to be jpeg file.

My camera is 6MP resolution and produces a 2MB file. Obviously I need to
resize/recompress the file. But resize to what? I could keep the high
resolution and use a high compression, or I could resize it to a low
resolution and use a low compression. Which combination results in the best
looking photo?

I could use photoshop to resize the photo to different resolutions, then
compress each one to just under 200KB, and then compare the end results. But
this is too much work.

Is there an easier way? I also have image ready, but I never use it. Would
it help?

peter wrote:
One of the classified ads site I use has a file size limit of 200KB on the
photo and it has to be jpeg file.

My camera is 6MP resolution and produces a 2MB file. Obviously I need to
resize/recompress the file. But resize to what? I could keep the high
resolution and use a high compression, or I could resize it to a low
resolution and use a low compression. Which combination results in the best
looking photo?

I could use photoshop to resize the photo to different resolutions, then
compress each one to just under 200KB, and then compare the end results. But
this is too much work.

Is there an easier way? I also have image ready, but I never use it. Would
it help?


If it going to be viewed on a computer screen, e.g. a web image, you
should make the image about 600 x 800 pixels so it can be viewed without
having to scroll around excessively. Save the image as a jpeg at Quality
9-10 in Photoshop. Check the file size and adjust the compression
accordingly if necessary.
Bob Williams

Bob Williams wrote:


peter wrote:

One of the classified ads site I use has a file size limit of 200KB on
the photo and it has to be jpeg file.

My camera is 6MP resolution and produces a 2MB file. Obviously I need
to resize/recompress the file. But resize to what? I could keep the
high resolution and use a high compression, or I could resize it to a
low resolution and use a low compression. Which combination results in
the best looking photo?

I could use photoshop to resize the photo to different resolutions,
then compress each one to just under 200KB, and then compare the end
results. But this is too much work.

Is there an easier way? I also have image ready, but I never use it.
Would it help?

If it going to be viewed on a computer screen, e.g. a web image, you
should make the image about 600 x 800 pixels so it can be viewed without
having to scroll around excessively. Save the image as a jpeg at Quality
9-10 in Photoshop. Check the file size and adjust the compression
accordingly if necessary.
Bob Williams

Yeah, what he said. Chances are the site is going to either re-shrink
it, or constrain the display size anyway, so there's no point uploading
a massive high-res, low-compression file anyway. 800x600 max JPEG with
a medium-low compression (or medium-high quality, depending on the
software used) should yield a file well under 100k, so size shouldn't be
a problem.

BTW, if all you're doing is resizing and resaving, Photoshop is serious
overkill - with something like Irfanview (small, fast, and free) you
could probably start the program, load the file, resize it, and resave
it, in less time than it takes Photoshop to even start up.


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Hi there,

Try http://www.tangotools.com/jpegsizer/

Hope this helps.

On Wed, 24 May 2006 04:34:22 GMT, "peter" wrote:

One of the classified ads site I use has a file size limit of 200KB on the
photo and it has to be jpeg file.

My camera is 6MP resolution and produces a 2MB file. Obviously I need to
resize/recompress the file. But resize to what? I could keep the high
resolution and use a high compression, or I could resize it to a low
resolution and use a low compression. Which combination results in the best
looking photo?

I could use photoshop to resize the photo to different resolutions, then
compress each one to just under 200KB, and then compare the end results. But
this is too much work.

Is there an easier way? I also have image ready, but I never use it. Would
it help?


Bye for now,

George Dingwall

Invergordon, Scotland

http://freespace.virgin.net/george.gdingwall/index.html

Agreed Irfanview is a great utlity for resizing, good algorithm etc.
But it doesn't hold a candle to Photoshop for editing, enhancing, and
sharpening files.

Tom

"Bob Williams" wrote in message
newsmScg.920$sP1.570@fed1read07...


If it going to be viewed on a computer screen, e.g. a web image, you
should make the image about 600 x 800 pixels so it can be viewed without
having to scroll around excessively. Save the image as a jpeg at Quality
9-10 in Photoshop. Check the file size and adjust the compression
accordingly if necessary.
Bob Williams

I prefer as detail a photo as possible because when selling used items, it
is advantageous to show the item without scratches, and 800 x 600 usually is
not sufficient to show such details.

When I am buying a used item, I also want to see a high resolution photo of
the item. Having to scroll around is a non-issue when I have to make a
buying decision based on the photo.

"Jim Townsend" wrote in message
...

Ask them what pixel dimensions they want. (IE. 1600 pixels x 1200 pixels)


There is no restriction on the dimension. That is why I want to optimize the
dimension + jpeg compression level.

It's not possible to give an exact answer due to the lossy nature of jpg
compession. The more detail there is in the original photo, the harder it
will be to reduce the filesize without introducing jpg artefacts.

Paint Shop Pro 9 (and I think 8 and 10) has got a good jpg compression
optimizer where you can see any build up in jpg artefacts in real time as
you change the compression factor, this helps you squeeze the maximum
compression before artefacts become visible. Typically, I wouldn't go
bigger than 800x600 using a compression factor of about 7 to give 200k and
very few artefacts. Any bigger (pixel dimensions) and it becomes really
difficult with many photos to keep under 200k without seeing artefacts. You
may get a slightly bigger image, perhaps 933x700 if you use some noise
reduction first before applying extra compression, as artefacts may be
fewer.

"peter" schrieb
One of the classified ads site I use has a file size limit of 200KB on the
photo and it has to be jpeg file.
cPicture can optimize picture size by given file size and quality when
resizing.
You can optimize any of the three by specifing the other two values.