Spot Selection & Neutralization

[curtism]

The attached photo has spots and fingerprints throughout. I've checked the channels and blue is marginally better, red is marginally worse, but all three still show significant spotting. I believe that using the calculations command is the best selection option but I'm not sure how to set it up nor how to proceed after I get a good selection.

Any guidance appreciated.


Curtis

[0lBaldy]

I hope your working copy is scanned in color and at a much higher resolution because this sample is pixelated.

I know nothing about calculations but am eager to learn.. So, I am waiting also for an answer to your question of how to apply calculations to this picture..

In the meantime I did a quickie using Imagenomic to initially get rid of some noise then followed this Tutorial for the rest

[lurch]

Curtis,

Since I was the one who led you into this calculations business, I guess I should take a crack at leading you deeper (OlBaldy too . . .). Gotta warn you this is an area where I get out of my depth real fast, however - it'll really be a case of the blind leading the blind.

For this image, calculations is a decent selection technique but as OlBaldy demonstrated one doesn't need to make a selection to do a good restoration on it. Practice is always a good thing to do, though.

First the mask. You'll notice at the very top of my workflow (attachment 1) a turned-off layer labeled contrast bump - it's a linear burn hue/sat layer with the yellow saturation set up to about 80 and the red set to -100. The idea here is to temporarily create strong contrast between the stains and the rest of the image. When that layer was active and affecting only the background copy, the channels in the channel palette reflected the strong contrast. So far this is vanilla 'masking 101'. Then I invoked Image>Calculations using the settings in attachment 2. That gave me a new channel, Alpha 1. Using calculations seems to be a matter of fiddling until you find a combination that does what you want - in this case you want the stain light and most of the rest of the mask dark. Using the curve in attachment 3 to increase Alpha 1's contrast gave me a fairly satisfactory mask. Wasn't perfect in that it didn't address every bit of the stain and had to have the white shirts, car, and hat painted out, but it was a good start. (BTW, it took longer to describe this process than to do it.)

Once the mask was made I used it twice - first for a curves adjustment layer to reduce most of the staining (use the info palette for guidance on which channels to adjust) and second for a hue/sat adjustment layer to subdue the last traces of color. The mask as I made it didn't pick up the little spots on the pants, thus the selective d&s filter. The remaining workflow is straightforward.

This was long-winded, wasn't it? You might think it's the hard way around, and perhaps for this image it is. Just depends on how much you like lots of cloning and healing. And practice is good.

[0lBaldy]

Thanks Lurch, Nice explanation! I will try to add this to my arsenal as soon as I am able to understand it! Me thinks I need practice cubed..

[curtism]

Lurch,

Thank you for the concise explanation. Because of your previous help, I was at least able to recognize that Calculations was the tool I needed. I had tried Hue/Sat, Dust/Scratches and lots of tedious healing/cloning but didn't come close to what you did. Where do I sign up for your class?!!

I have many photos with this type of problem in varying degrees so that means lots of opportunities to practice. I'll post additional samples as I develop this skill.


Curtis