Changing a specific color to transparent

[EarlMorton]

I've been working on this for about three hours. It seems like it should be an easy, basic function of the program. I have a scanned, black-and-white image of a page of text. I want to remove the white background, leaving the black text on a transparent background. I have tried both the Recolor and Eraser tools, but am getting nowhere. For Recolor, I have tried both Sampling modes and several Tolerance settings.  For both tools, I have tried several settings of Hardness and Spacing.

 

I have also searched this forum and the online documentation, but have not found a solution. When I started, I expected this to take about 20 seconds. Clearly, I am missing something. What is it?

 

Thanks!

[BoltBait]

Try this:

 

Select the magic wand.

Switch the Flood Mode to global.

Click on the color you wish to remove.

Press the Delete key on your keyboard (not the backspace key).

[Tactilis]

48 minutes ago, BoltBait said:

Click on the color you wish to remove.

And then adjust the Tolerance so that the selection encompasses all of the 'white' background, which is unlikely to be a single uniform colour in a scanned image.

[EarlMorton]

Wow! That was as easy as I thought it should be. Thank you very much! I was not aware of the Magic Wand's Flood mode.

[Tactilis]

10 minutes ago, EarlMorton said:

I was not aware of the Magic Wand's Flood mode.

Take a look at the Documentation here: https://www.getpaint.net/doc/latest/MagicWand.html.  Note the use of Shift to temporarily enable Global flood mode, the use of the different Selection Modes, and the technique of inverting a selection.
 

It's worth setting aside a little time each day to work your way through all the Documentation and to try out all the examples shown so that what you read sticks in your mind.

It saves a lot of time in the long run and improves your technique.