Darken pencil drawing

[spaceman]

I have a scanned pencil drawing, so it's kind of shades of gray (no, not 50).

How can I make the lines black?

So far I have removed the white background by doing Color to Alpha.

I've tried to adjust Brightness/Contrast and Color Balance That did nothing.

[meetdilip]

Select by colour and bucket fill using black ? Might help.

[PixLab]

Many ways to do it, I'll just give you 2 quickies

Fast and easy for pure black and white: Colors > Threshold... on your original scan (remove the white after)
Adjust with the sliders, if it's too harsh > then after Filters > Blur > Gaussian blur... just a bit to smooth it out

   

Or
Colors > Levels...
Click on number 1 then pick the black on your scanned doc, adjust with sliders (number 2) if needed

   

My favorite is a S curve with Colors > Curves... as it allows multiple controls
Red arrow is a darker part (blacks), yellow arrows is lighter part (whites)

   

[sallyanne]

Couple things you can do
Double the layer and put the top layer into multiply mode
or 
assuming the background is white? duplicate the layer and colour to alpha it (making the white transparent then dulicate that layer a few more times.
or
Using threshold should make your grey darker this is actually your best option.
or
using curves you bring the curve down in the centre
or using levels at value bring the centre arrow to the right

[spaceman]

(10-11-2021, 06:24 AM)meetdilip Wrote: Select by colour and bucket fill using black ? Might help.

Thanks, but this leaves patches of Gray.

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(10-11-2021, 07:14 AM)PixLab Wrote: Many ways to do it, I'll just give you 2 quickies

Fast and easy for pure black and white: Colors > Threshold... on your original scan (remove the white after)
Adjust with the sliders, if it's too harsh > then after Filters > Blur > Gaussian blur... just a bit to smooth it out



Or
Colors > Levels...
Click on number 1 then pick the black on your scanned doc, adjust with sliders (number 2) if needed



My favorite is a S curve with Colors > Curves... as it allows multiple controls
Red arrow is a darker part (blacks), yellow arrows is lighter part (whites)

I'm getting problems with all methods. I guess I need a cleaner drawing to start with. Thanks for your suggestions

---

(10-11-2021, 07:16 AM)sallyanne Wrote: Couple things you can do
Double the layer and put the top layer into multiply mode
or 
assuming the background is white? duplicate the layer and colour to alpha it (making the white transparent then dulicate that layer a few more times.
or
Using threshold should make your grey darker this is actually your best option.
or
using curves you bring the curve down in the centre
or using levels at value bring the centre arrow to the right

Thanks. My original is not clean enough. Guess, Gimp is not magic

[sallyanne]

Threshold will make your dark areas darker, and your lighter areas lighter

Second thoughts - can you upload it? Someone may be able to do it for you or tell you how they did it so you can...would be easir to tell you what to do if we could see what you want to change.

[PixLab]

(10-11-2021, 12:20 PM)spaceman Wrote: Thanks. My original is not clean enough. Guess, Gimp is not magic

Can you upload your draw? (or at least the most difficult/intricate part of your scanned draw.)
This will able us to find the right method for that specific scanned draw and define what type of magic we can do or not

[sallyanne]

[attachment=6845]
Ok I desaturated an image and made it look like a  pencil drawing then made it lighter.
I ran the color > threshold on it and here is my before and after
[attachment=6846]