On July 13, 2016, paint.net issued an update. The update caused paint.net to sometimes start up in a virtually worthless mode that doesn't include the cloning tool and the "Auto-Level" feature described below. I'm not sure what causes it, but it usually goes away when you start it a second time.
When I digitized all my photographs that were in slide format, I also converted about 2,400 regular photographs to digital format. About a third of the photos were in black and white. The rest, of course, were in color. Color negatives look like faded color photographs, and the gizmo I used to do the digital converting also converted the negative images to positive color shots. But, it appears that some of those photos were also slightly faded and also have blemishes. Since I'm working with negatives, the dirt spots and blemishes tend to be white, not black as they were with slides.Here's a photograph I took in Venice as it looked before I used the "Auto-Level" adjustment feature in paint.net (you can click on the image to view a larger version):
There may not be any way to tell if the color needs adjusting or not, until you do it. It could have just been a purplish day in Venice. But, it's clear that the dark line down the right side shouldn't be there. Evidently, the negative just wasn't properly positioned in the gizmo device I used to convert the color film negative to digital format.
There were no blemishes to eliminate, so here's the same photo after I used the "Auto-Level" adjust feature to adjust the colors and after I used the cropping feature to eliminate the black edge:
Obviously, the colors did need adjusting.
I also found a photograph I took in Monaco that had a bad scratch that definitely needed fixing. The colors looked in need of adjustment, too. Here's what it looked like:
There is not only the white scratch in the lower right corner, but there are also lots of white dust spots in the sky and elsewhere. Using paint.net's "Clone-Stamp" tool, I fixed the blemishes. And here is what the final image looks like:
The next step for me was to figure out what the building was in picture. I always thought it was the Grand Casino in Monaco, but when I looked for current images of it on the Internet, I found that it could also be the Monaco Opera House, which is part of the Casino Royale in Monaco (or vice versa). I finally figured out that it's the view of the side of the building that faces the Mediterranean. That's the Opera House side. The main entrance to the casino is on the opposite side of the building.
Live and learn.
Another thing I learned is that I should have spent more time during the digital conversion phase figuring out when the pictures were taken (or developed) and using that date as part of the names of the picture files I was creating instead of letting the conversion program assign file names. I think the pictures above where taken sometime in the 1980s, but I'd have to find the packet with the negatives to be certain. The develop date is usually on the packet, and it could also be on the end or side of the strip of negative film. Most of my photographs are also in albums where photographed dates and other information is included with the photos.
For my experiences color adjusting and repairing digitized slides, click HERE.