Here is my non-destructive photo restoration workflow for restoring vintage photos.
- Open your image in Photoshop and analyze it. What the biggest problem with it? What needs to be done? If there is a drastic color shift problem, address that first by adding a Curves adjustment layer and adjusting the white and black points and other colors as necessary. If there are no major problems besides dust and scratches, rotate (if necessary), crop and proceed to the next step.
- I like to deal with the small sharp dust first because it's easily fixed with the Dust and Scratches filter. In the layers panel, right click on the layer with your photo and click Convert to Smart Object. Select Filter > Noise > Dust and Scratches. The radius and threshold values will depend on the resolution of your photo but I usually try a radius of 2 or 3 and threshold of 15-20. Click OK.
- Fill the Smart Filters layer mask with black to conceal the Dust and Scratches filter effect. With white as your foreground color (white to reveal the Dust and Scratches effect), click and paint to hide the small bits of dust using a small brush in detail areas, large brush in background areas. I recommend against flooding the whole image with the Dust and Scratches filter - it ends up blurring too much image detail.
- For the bigger pieces of dust or damage that can't be fixed with the Dust and Scratches filter, I use the healing brushes and sometimes the clone stamp tool. Create a new layer above your original image layer. If you have a Curves layer, make sure it is below the Curves layer.
- Select the healing brush and set it to Sample: Current and Below. Select the clone stamp tool and set it to Sample: Current and Below. Select the spot healing brush and set it to: Sample All Layers (there is no Current and Below option). Click and paint with these three tools as needed to get rid of all dust and damage.
- If you haven't done Curves in the beginning, go ahead and adjust the image now.
- Now for one of my favorite shortcuts: In the layers panel, select all layers and press Cmd-Opt-E (Stamp Layers). This merges a copy of all previous layers into a new layer on top. Apply sharpening to this merged layer with your favorite sharpening method (I like High Pass).