Removal of Scale effect from a photo

[jmn]

I have some old photos that seem to have a fish scale effect on the surface, sort of a screening effect I guess.

I work with very high resolution scans, topping out at 6400 dpi progressive.
I have already tried digital ICE and Neat Image and the loss of detail is high. Digital ICE gets confused and spits out garbage.


I would have thought that someone would have developed software to take care of this sort of noise, as this noise is uniform and predictable, not requiring noise searching.

Any suggestions or methods that work?

[chillin]

Search posts about FFT filter.

[Kraellin]

yup, you want FFT or the rgb fft or, try image analyzer which has a built in fft filter.

[0lBaldy]

Craig, I had not tried the FFT in "Image Analyzer" (found here) before you just mentioned it... WOW what a difference and easy also.. I think it looks better than the FFT I have been using and MUCH simpler to use.. black the stars click OK.. BLAM!
Thanks for enlightening me!

[DCobb]

I have had Image Analyzer on my computer for some time. Tried the picture, and yes it does a lovely job--and fast! However, there does not appear to be any way to save or copy the picture to take the transformed picture into Photoshop. Any Ideas?

dc

OOPS--solved the problem by converting the image to grayscale while in IA

[chillin]

Can't you use save as?

[DCobb]

Hi Chillin,

Thanks for your reply. Did try to use save as but the file format that I was in after running the FFT filter could not be saved in any file format that could be taken into PS. When I converted it to grayscale, then I was able to save it as a JPEG.

dc

[chillin]

Are you using the latest version of Image Analyzer?
Maybe, you could try to reinstall it.

[DCobb]

Hi Chillin,

Yes, I removed my old program and did install the new (I think March 2008). I went to the help site and they indicated that on the FFT transform there was no way to save it in that format so that it could be imported into other software. As soon as I took the completed transform and changed it to grayscale I could SAVE AS as JPEG. However, when I ran a color image through the FFT and Inverse FFT I ended up with a grayscale image and was not able to merge it with the color copy as you do as a last step using the regular FFT program.

Thanks for your thoughts,

dc

[jmn]

Alex Chirokov's FFT and Image Analyzer run out of memory on large images, so they have non-existent memory management. Memory management and split algorithms get around this on 32 bit software limitations. (ptGui and NeatImage have addressed this issue for example).
I could fix Alex Chirokov's FFT filter but I'm not sure a 64 bit plugin in a 32 bit app would work.


--> Is there any FFT filter out there that doesn't have this issue. <--
I know GIMP wont have this issue for sure, since you can recompile this for a 64-bit architecture thus solving the memory limitation in a blunt way.

The FFT filter doesn't have to be 64 bit, but should incorporate some trick to bypass the 32 bit memory limitation.

[lurch]

Try ImageJ (http://rsb.info.nih.gov/ij/download.html).

[Kraellin]

OB, you're welcome. and yes, image analyzer has some surprisingly good stuff in it... and, it's free

[lurch]

Craig, for the record ImageJ is also a powerful image analyzing/processing program, is free, and is available for Mac and Linux as well as Windows . . .

[Kraellin]

lurch, yes, glad you're posting about it. i've just never used it, so cant really speak for it. glad you are, though

[chillin]

Originally Posted by DCobb

Hi Chillin,

Yes, I removed my old program and did install the new (I think March 2008). I went to the help site and they indicated that on the FFT transform there was no way to save it in that format so that it could be imported into other software. As soon as I took the completed transform and changed it to grayscale I could SAVE AS as JPEG. However, when I ran a color image through the FFT and Inverse FFT I ended up with a grayscale image and was not able to merge it with the color copy as you do as a last step using the regular FFT program.

Thanks for your thoughts,

dc

In Image Analyzer I use "Frequency domain filter". Sorry, I didn't pay attention.
For FFT (lurch posted the link) I use ImageJ.