Wow, FFT

[yardkat]

Hello everyone,
I am pretty new to this site, I saw a post on the Online Photographer about a live webinar with Ctein last Saturday and signed up. It was a very informative webinar, mostly to inform me that I don't know anything about restoration!
I'm not a pro, just an amateur who enjoys working on old family photos. I thought I was doing a good job, but now I see there's so much to learn.
Anyway, since then I've been digging in to the forums and reading, and learning that I don't know anything! But I learned about the FFT filters, and downloaded both ImageJ and Image Analyzer to play with. Holy cow, the results can be amazing. It's going to be very difficult not to re-do everything I've worked on til now.
But I have some questions, all this new stuff is a little daunting!
What part of your workflow is the FFT filter? My instinct is that it should be the first thing one does, but what do you do to your files in terms of size?
So I guess I overscan a bit, so let's say I've scanned at 1200dpi, would I immediately change it to 300dpi to work FFT and then just do all the remaining editing at 300dpi? Basically most of my scans are too large and ImageJ says it doesn't have enough memory. (I do think I've gone in and changed it to the maximum allowed.) Usually I don't change the dpi until it's time to print.

Specific question about how to use Image Analyzer: I open the file and run the FFT, do the work on the star, then IFFT, then the photo is just black and white and I don't know what to do at that point. Also, I don't understand the file types available when I Save As. What should I save it as, and then how do I edit?

I've had better luck figuring out ImageJ, except for the file size issue.
I use Windows 7 and CS4, my scanner is an Epson V700.

Thank you all in advance for any help about these programs, I very much appreciate it!
Julie

[Britsdad]

Hiya Julie, and welcome to RTP,

I always run the filter as the first thing I do, if I get the error about memory I cut the image into 4, or even 6, run the filter on all, then put it back together after.

As for what to do after the IFFT filter, you need to duplicate your image before you run the FFT filter, then when all is finished and you've got your black and white image you need to drag that back into your original image, making a new layer, then change the blend mode of that layer to "luminosity" and voila done.

Hope this all makes sense......John

[yardkat]

Hi John,
Thank you for your reply and help. I apologize in advance for the stupid question that I'm about to ask, but could you explain or point me to someplace that explains how to cut the image into smaller pieces and put it back together? I've experimented a bit, but there must be an easier way. Thank you.
(sheepishly hanging head...)

[Britsdad]

Sent you a PM

John