Any software to change image to black and white?

i have some scanned images which i want to turn into black and white to print it so as i dont get greyed parts
so is there any software in manjaro that can do this to a single image or a pdf file?
in windows i was using: Convert images to monochrome in PDF files. []

Maybe this. It does have greyscale but MIGHT have what you are looking for;

Install imagemagick

sudo pacman -Syu imagemagick

Do the conversion

convert somepdf.pdf -monochrome bwpdf.pdf

You could scriptify it too.
A quick single line example of converting all files in the current directory to black and white;
(after first dropping all files in, example directory ~/convertpdfs, so cd ~/convertpdfs then)

for f in * ; do convert "$f" -monochrome "bw-${f}" ; done

Krita has a simple menu option to achieve the required result.
Once an image or PDF file is loaded, simply choose from the toolbar:

  • Image → Convert Image Colour Space
    …and select:
  • Model → Greyscale/Alpha

Additionally, if the gmic-qt package is also installed, you have access to a host of filters via:

  • Filter → G’MIC-Qt

A fair selection to choose from under the ‘Black & White’ category:

sudo pacman -S krita

I hope this helps. Cheers.

1 Like

Try loading your image in Gimp.

2023-12-24 14:33:57

Context menu, Filters>Distort>Newsprint

2023-12-24 14:36:10

Zoomed out, the image looks good - but without actually printing grey areas.

I show here the ‘dot’ pattern, but actually for a larger image where you shouldn’t see the marks - the line pattern is actually very good in it’s appearance.