using ms paint as a map editor

Unity Editor
1

So, hypothetically speaking, would it be possible to convert an png file into a tile map?

I mean, I could convert a png to a 2d array, then use the numbers as tags to place various tiles.

Correct?

Any suggestions on how I could convert the png to a 2d array inside of unity?

And once I do that, how could I assign tiles to various values OUTSIDE of runtime so that I can look at it and edit it?

2

might also be of interest: UnityPaint – Arongranberg.com