I have a i5-3427U CPU @ 1.80 Ghz and an Intel HD 4000 internal graphics card.
The selection indicator is the blinking line around a selected area in an image. E.g. it is drawn after the selection tool was used.
The implementation of the selection indicator is pretty poorly implemented regarding performance. Just follow those steps to reproduce:
Monitor your taskmanager while doing the following steps
Get any image data into your clipboad, e.g. make a screenshot
Do Ctrl-N, Ctrl-V many times in Paint.net
You will see, the CPU usage increases on each image
CPU usage shouldn't increase each time a new image tab is opened. The thread should stop on the other tabs that aren't visible
CPU usage keeps constantly high if I have another window shown above Paint.net. Some days my fans are blowing the whole day due to high constant CPU usage until I realize that Paint.net is the cause once again.
If I do Ctrl-D in each image tab, CPU usage goes to nearly 0% again
If I minimize the window, CPU usage is almost 0%. But in my normal work routine I never minimize windows. I rather put other windows above.
The selection indicator shouldn't use that much CPU power in the first place. There must be a much more efficient way available to implement it
Last but not least: Guys, you have so many installations out there. That fix will reduce the global energy consumption! Think green...