My father is a professional photographer(he went to college for it and everything) and he has a 721mb folder of 162 pictures he wants on one disk. If I reduce the quality of each picture by 1%, I'd easily be able to fit the group on a 700mb CD-R. The only problem is that opening each picture in paint.net and saving at 1%reduced quality would take forever. Are there any programs I can use to take the whole folder and reduce the quality of each image in just a few clicks?

In before Nikky charges in and says that a professional photographer would be shooting RAW, not JPEG. I don't know any such bulk quality decreasing programs off the top of my head, but I would be very unsurprised if a GIMP script existed for it. Have you tried zipping them and seeing if that gets the collection under 700MB?

7z. It'll take more processing power to compress, but you'll get better compression.

Yeah, I thought about that, but then I wondered if perhaps the reason his father was trying to fit all the photos on a CD was that he was distributing them, and a lot more people can read zips than 7zs.

XnView has a batch processing and conversion mode (Tools->Batch Processing).

I'll burn that on to two CD's. On the second CD you just add information such as an itemized text file of the photos with basic info then another one for my photographer info: website, name, e-mail, phone, copyright status etc.

No professional photographer would ever shoot JPEG. However, they would send JPEGs to clients, friends or family

My dad only shoots jpeg because they're easier for someone as computer illiterate as he is to work with. I'll give XnView a shot, thanks.

Try zipping the files first.

Gimp has a batch process plugin that works fairly well in my experience. That also may be worth looking into.

XnView has the options I need, I just don't know which ones to toggle how in order to reduce the quality slightly. The first time I tried it I ended up doubling the filesize. Lucky I made a backup first. I'll get it eventually after some trial and error.

@Svenne, I can't zip them because they need to be readable by a photo kiosk so prints can be made, as well as the faculty at the school for which the pictures were taken.

Use Adobe Bridge batch processing.

Under Output, Format select "JPG - JPEG / JFIF", click Options and adjust the Quality slider. You'll probably also want to select a different output directory rather than the default one (which will overwrite the files as you're converting from JPEG to JPEG).

First of all, make sure you're keeping a backup and working with a copy.

I use IrfanView for all my batch processing. Hit B, choose the Batch Conversion radio button, choose Output format: JPG, then change the Save Quality via the slider from the Options button adjacent to that. (Other transformations can be found by hitting Advanced.)

Below that, change the Output directory (preferably to a temporary folder so that no files are overwritten), and choose the Input files on the right. Add in the entire directory you're viewing with the "Add all" button. When ready, press Start Batch in the lower left.

I suppose it can't read DVD's?

Read yes, write no. Even if it could, I would be taking up less than half a DVD, and I'm very very close to the filesize I need to fit on a CD-R.

http://www.kenrockwell.com/tech/raw.htm
This is why my dad doesn't shoot RAW. Also he wanted me to tell you that "the people shooting raw are the people on their computers counting pixels instead of going outside and taking f--king pictures!"

After this program finishes with this second attempt(I've been using backups and saving to separate folders from the beginning) I'll list the settings I don't know how to use and you guys can educate me.

EDIT- it worked. 95% quality and the default subsampling factor cut the total filesize by over 200mb with no apparent loss of fidelity. That being said, I would like some clarification as to what some of these do:

Progressive

Optimize Huffman

Keep EXIF Data

Keep IPTC Data

DCT Method(Slow, Fast, Float)

Smoothing Factor

Subsampling Factor

Thanks again, this will make sending my dad's pictures en masse much easier from now on.