saramello

Like say I have a square picture that I want to re-shape into a triangle. Could it be possible to "paste" the square picture into a triangular or custom shaped frame and have it auto-resize to fit within those dimensions without any cutoffs?

Ah ok. I will try this out this weekend. Would it be easier to use an easier hue to copy paste then just re-color it at the end? If so, what is the best hue/s to do so?

I use paint.net to make maps, using a blank map template and fill in the states. The problem is once I fill them in, I have to spend a lot of time disconnecting all the internal borders (in one country) from the external borders (separating different countries), then using paint bucket to remove it. This requires me to cut every single line, and if I miss one, every line on the map is turned into the color of the country. This takes a lot of time. With that in mind, is there a way to tell paint.net to fill in all the internal lines surrounded by the same color? Then again I know paint.net works wonders but this might be too niche

Here. It should be easy as these lines are completely isolated to their own layer, nothing around it.

The title says it all. I have several 2 pixel wide lines in an image that I need to make 1 pixel wide. Going through and either re-tracing or erasing half is very time consuming. Is there some plug-in or built in feature that would automatically thin lines?