Working on old scanner negatives and masking from IR channel

[Fujiprime]

Hi,
Looking for some ideas on this. I have been scanning old photos and discovered many have really bad fungus damage. I have scanned and then scanned the infrared channel to give me an image of the fungus.

Now with this mono image, sample attached, I want to add it to a layer over the coloured image and use it to select the damaged parts after which I can use the inpainting brush tool to lessen the visibility of the fungus.

How can I select/mask using this IR image to make selection? When I used Photoshop I could select and use the alpha channel to create a mask or selection.

Many thanks in advance.

[NotMyFault]

You can use rasterized to mask.

to prepare, use levels adjusted to boost contrast if needed or invert layer.

[NotMyFault]

In case you want to modify the greyscale layer, e.g. feather, smoothen, grow or shrink, this can be done easily in form of a selection.

principle workflow:

• have the mask ready as mask layer
• selection from layer
• use grow/shrink, feather, smooth etc on the selection
• create a new mask from selection to save the result.

[Fujiprime]

NotMyFault, thanks for the advice. I'll try it later.