Can I easily and automatically fix contrast and color on a 35mm scan that contains sprocket holes?

Question

I often prefer to scan film including the sprocket holes, especially when the image bleeds over the perforations a little bit, as in this example:

The raw results from the scanner are usually very bland. Whenever I scan without perforations, I fix this by using Auto Tone/Contrast/Color in Photoshop, which is fast and gives acceptable results.

But when I scan with the perforations, using these commands does not work, probably because of the perforations throwing off the way the program perceives the image.

Inside the dotted selection, the correction provides a proper result:

However when applied to the whole scan (including perfs), the Auto commands do not produce a good result:

I wish I could "sample" part of the image that I want to fix automatically, and then apply this to the rest of the image.

I prefer not to create presets or actions but would rather use an auto feature, since I use different film stocks all the time.

I am sure that if I selected the exposed parts and deselected the perforations and edge markings, the Auto commands would work a bit better, but I am trying to find a quick way to balance these scans and restore the dullness that the scan produced. I'm open to try a new app if one does what I'm looking for.

How can I balance these scans out?

Answer 1

In Gimp I would do:

• Using the Select by color tool (not the Wand), click in one of the sprocket holes (this should select all of them)
• Select > Invert so everything is selected except the sprocket holes
• Apply whatever auto-processing (which would also exclude any very dark spots in the image)

You can certainly do the same thing in PS.

Answer 2

Someone showed me how to do this outside of stack. Here's the way:

1 - Select the area of reference

2 - In the Layers Panel, create a new Curves Adjustment Layer

3 - Click Alt and the Auto button of the Curves Panel and Select the Algorithm that produces the best result in the selected area

5 - Delete the Layer Mask in the Layers Panel to apply the effect to the whole image

This is an easy process to record as an action for quick repetition.