Upsampling

Hello Everyone,

I remember that in older versions of Photoshop it was recommended to go in several small steps when upsampling an image from, say 300 to 600 dpi. Is this still necessary with 7.0 and CS? There was also a sort of "formula" to calculate the increase in each step - does anyone know what it is?

Also, a while ago someone recommended a software program to me (might have been a PS plug-in) which has advanced mathematical formulas for upsampling - he made super sharp huge poster prints from a 4.0 MP Camera with it. Does someone know about this?

Always glad for any help and suggestions
Thanks,
Q.

I never do this, but i'll try to help.

I dont believe version makes a difference, unless in newer versions (im on 6) they have massively improved resampling.

Even if that was the case, the way resampling works, you would still lose some image quality (you'll always lose image quality going from smaller to bigger ). As I understand it, going in small steps allows you to edit the image at each step (sharpen/color adjustments), to achieve as much quality as you can. So instead of jumping from one size to the next, you "help" it along until you get a desired result.

My advice is, do it anyways, it cant hurt. Most likely it is still necessary.

With a quick google, i came up with 10-15% enlargement each step (no more than 15). Not sure if thats the "forumula" you want.

As to a plugin, no idea. You'll have to google that one.

Hello Rodder454,

Thanks for your help. I also googled for upsampling software, didn't think I'd recognize the name of the one that was recommended to me but I did - the program is a PS Plug-in called "Genuine Fractals". From what I've seen, it works quite well.

If anyone else is interested in this, a quite comprehensive overview of all resizing methods and available software as well as test images can be found here:
http://www.americaswonderlands.com/digital_photo_interpolation.htm

Thanks again,
Q.

Genuine Fractals is a pretty phenomenal piece of software. I have used it personally, and seen it used in a printshop. I was more then impressed with the results.

I use Photoresampling. It's nice. You can find a demo version at http://www.photoresampling.com

It seems like I upsample every day. People bring in small digital pictures to my shop and ask "can you print these?" I hate that.

I don't use an upsampling plug in. I made a very long, drawn-out action that upsamples, cleans and resizes (mostly 4x6) my pictures for me.

I also have a 15% upsample action. When I want to do it manually, I press F5 (I assigned that key) and go from there, cleaning, etc.

If you find you're upsampling frequently, I suggest making an action that does it for you.

Crypto(\/)aniac