Save the .jpgs as .gifs

Yep, save as .gifs, make sure you click the transparency box.

Thanks guys -

I need a different way to do it though - when save for web / GIF is selected - it's too "rough" - there's lots of white noise around the area where the white was knocked out -
this always happens w/ GIFs (at least to me) so I always opt for PNG24 - that does a much smoother, better job.

(These logos all have a lot of smooth transitions, etc. that also aren't supported well w/ GIFs)

but the PNG save for web settings don't work the same way as GIF - when you check "transparency" the white doesn't drop out the way it does w/ GIF...

Does that make sense?

with some research, I'm discovering that what I need to support is FULL ALPHA TRANSPARENCY - PNGs support that, GIFs don't

-just in case that helps

This probably might be too much of a pita for a quick job but you can check out brandsoftheworld.com to see if any of the logos are hosted there in vector format.

Only PNG-24 to be exact (PNG-8 has the same single-level transparency as GIF). To simulate multi-layer transparency with a GIF, simply save with a matte the same color as the background you'll be placing the logo against.

In addition, it would be better to track down the vectors.'

Jpeg's get recompressed every time they are open and saved, etc. You are going to see the blockiness and white artifacts unless you go into every logo and get down to the pixel level.

Yep, as ned said, png-24 is going to work the best for you - but it doesn't have full browser support - issues with IE (so you need to use an image replacement or deal with ugliness). Probably the gif w/ a matte the same color as your bg is your best bet.

The "white noise" is aliasing trying to make it look a little smoother for you, what you can do is if you know roughly the color of the background showing through, you can say use that color to alias and it will turn the whites more towards that color and blend better.

It's called matte in the save for web feature.

Thanks everyone. The main problem we were encountering is that the images we could get our hands on were predominantly JPG's - single layer, with a white background.

That being said, removing the image from the white background would be time consuming (there's over 100 logos, PLUS the client would need to be able to do this down the road on their own) , AND, more importantly - not work terribly well via the magic wand tool or color replacement - because most of the logos are fairly detailed, it's very difficult to get the anti-aliased edges to cut out cleanly -

Yes PNG-24 is the way to go (I have a script I can plug in so that it's functions properly in IE6 or earlier) it's just getting the images to the point where the white space is gone. PNG unfortunately doesn't have the option, as GIF does (at least in the Save for Web in PS) to simply check "transparency" and the white space drops away...

Adding to the issue is the fact that the background is multi-colored - not a simple 1-color where a matt would work -

in the end, we opted to display the logos w/ a white square around them - we partially justified this because removing the white space could, technically, disrupt the integrity of the logos themselves - some of them probably have white in them that's supposed to be there, and we argued that this was the best way to go

>>PLUS the client would need to be able to do this down the road on their own<<

That's the fly in your ointment here. Doesn't matter how pretty a grave we dig for our work with this approach, it almost always backfires.

use Vector Magic. I use it and it works great. Converts any bitmap image (any pixel based image) to a vector.

^ Wuh?

Why would you want to do that in this case?