Hey there :-)
I just finished my latest restore and while I was working on it I thought that I could just show you a thing or two, that I already talked about in the video tutorials I just uploaded, but in a little different way.
First let me show you the image how I got it:
So after a little repair it looked like this:
Nothing special so far but look at all these spots around the image.
To make things a little faster I used a trick I explained here:
http://www.operationphotorescue.org/forum/index.php/topic,2687.msg25171/topicseen.html (it's the "Frequency Separation LOW-HIGH-COLOR").
So I separated the image into two frequencies. I blurred the bottom layer with the Gaussian blur and a 30Px radius, used the "Apply Image" command to get the high frequency layer and set its mode to "Linear Light". Again, nothing new so far.
But here comes the little trick ☺. I then deleted the low pass layer and inverted the high pass (looks like a blurred mess now). To get all those details back I then used the Gaussian blur filter once again on that inverted high pass layer with a radius of about 5Px and see what happened:
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Some of the spots disappear, some get more subtle (of course I had to use a layer mask and mask in just the spots because some areas became to blurry still)!
Nice, but not all the way there ;-)
The final steps were done with a dodge & burn layer (a new layer above all filled with 50% gray in "Soft Light" mode on which you can paint with white to lighten or black to darken specific areas).
I tend to use two adjustment layers to help me visualize where to dodge and where to burn. One is a Hue/Saturation adj. layer to desaturate the whole image and the other one is a plain curves adjustment with a lowered midpoint to get more contrast.
After your done you should delete or hide these layers of course.
If you want to see, how much d&b it still took, take a look :-):
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So after a final curves adjustment I came to this final version:
So I hope you enjoyed this little walkthrough and maybe were even inspired for future work on those nasty spots on your images ☺.
Of course, as the image is not uploaded yet, comments and critics are still very welcome :-).
PS: Please don't try to use the frequency separation to get rid of the defects in your image as the first step as that'll about never work out. The three steps involved is get the contours of the image, invert them and then blur away the details, so a radius small enough to blur the defects would also kill all your details!
