[colman77]

Whenever I encode pictures in jpeg format using windows paint/photoshop, and sometimes w/ digital cameras, details in the pictures look awful. It looks like there's digital wrinkles around the outlines of everything.
Now, ms paint I can pass it off as crappy software/compression/whatever but this shouldn't happen with photoshop. It must be something I'm doing, but I don't know what.

Was that clear? Do you know what I'm talking about?

TIA

[Saint Anger]

When you save a JPEG with a program like Photoshop,
you have options of how much compression is used.

Zero compression will yield the highest picture quality,
...and the largest file size.

Adjust the amount of compression to suit your needs.

...

If the pics look 'bad' right from your digital camera,
Then read your manual and see if there is a mode
or format that will produce better image files...

...

http://www.photo.net/learn/jpeg/

http://www.faqs.org/faqs/jpeg-faq/part1/

[hewee]

Like Saint Anger said.
Most image program by default has it so that .jpg, gif files are compress. Some by default are compressing up to 20 % so you need to change the setting. Also some will change back to the default setting so look for a save new setting or something like that in the options.

[kath100]

It also depends on the quality of the original jpg. If the original jpg is low resolution, compressing it will only make it worse

[hewee]

See http://www.scantips.com/

[colman77]

Thanks for the info all! Cleared up many questions/myths I had.

[LONGHAIR]

What you are refering to is known as "artifacts" which are generally caused by too much compression or saving the pic too many times.
The more sophisticated editing software packages will have tools to reduce it. The level of success depends on how bad it is to begin with.

As a side note:

When ever you have an image that you will want to edit more than one time, save it in a lossless format like PNG or even BMP then it can be re-edited w/o compression messing it up. You can save the final version as jpg for E-mailing or whatever.
This does not happen from merely closing the image, just from "saving" it.