Using the full color range

[DryToad]

Let's say I have an image made with white (0), gray-ish white (64) and gray (128). What inbuilt tools / plug-ins could I use to "rescale" (I have no idea what's the word for this) these values so that I use the full range, ending up with something like 0, 128 and 255?

(I suppose levels does that but I have no idea how to use it, and if there is a plugin that does something like that I would like to know)

 

Many thanks!

[BoltBait]

I think what you're looking for is:

 

Adjustments > Brightness / Contrast

[ardneh]

 

 

 

 

Move the Input bottom slider up to 64.

 

Edited May 26, 2021 by ardneh

[MJW]

Though it wasn't designed specifically to do this, the Texture Scaler plugin will stretch a grayscale image to span the entire range. Just uncheck Produce 24-Bit Height Map and leave the other controls at their defaults.

 

EDIT: If the image contains transparent pixels, you should check Don't Scale Transparent Pixels.

[DryToad]

Thanks for the replies, everyone!

 

@BoltBait thanks for reminding me that tool existed, I guess I was thinking so much about curves and levels that I forgot about the basics.

@MJW, do you have a magical box from where you take out a plugin for every need I have? Sadly, the scanned documents I wanted to enhance seemed to have some very dark pixels scattered around, so the changes it made were near to none. I ended up going with @ardneh's tip. Using the levels tool wasn't so difficult after someone told me what slider to use (thanks dude), and once I realized I could use the histogram to figure out where to stop. Definetively using your plugin for other projects tought, having a task automated is always great!