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Recommendations for Scanning Slides

Started Aug 7, 2021 | Discussions thread
ProfHankD
ProfHankD Veteran Member • Posts: 9,147
Dust removal without an NIR image

iljitsch wrote:

I used an Epson scanner with slide and negative scanning attachments to scan slides and negatives. Took a good amount of time, but now I have digital copies of all my slides and negatives.

Biggest issue: dust and other debris. I understand that this can be largely fixed in software for color film/slides if you have a scanner that has an infrared channel. So I'd highly recommend that.

Flatbed scanners tend to have more of a dust issue than other methods of slide scanning -- after all, they have a piece of glass fixed horizontally near the focus plane and it can get dusty.

The dust/srcatch removal is generally done by capturing an NIR image to use as a mask. The dark pixels in NIR are simply interpolated over. A better fix would be to do true inpainting to fill the gaps. I was thinking I could write code to automatically recognize and fix the dust spots without NIR, but it's been done: Automatic Sensor Dust Removal . Yes, that's essentially the same problem as dust on scanned film. Anyway, they link to python OpenCV code that finds the spots & inpaints to remove 'em: Python-Automatic-Sensor-Dust-Removal .

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