Gimp 3.2 create indexed color image ist different from 2.10

[bluedxca93]

Hi, 
I did try to create a Screen Print draft
Then because of my sloppy File saving as jpg i wanted to reconvert IT to PNG and only as two colors to Print  black one a transparent foil using a normal laser printer. However the indexing mechanism somehow works different on Gimp 2.10 and 3.2. The thresholding Filter also behaves very differently. New Version works better for high res while Gimp 2.10 IS more accurate on Low res. Ist there a reason or an explanation what exactly changed with 3.2?

[rich2005]

I can not see any great difference between Gimp 2.10 and Gimp 3 but not to say that you do not have differences.

A jpeg by definition is 8 bit (..can be RGB / CMYK and indexed)  

As a test comparing 2.10 / 3.0 Mode -> Indexed (black and white 1 bit) no real difference

   

Comparing threshold and again no real difference.

   

It will help if you give more details of the image(s)  and workflow.

For Gimp 3.2 then there is threshold and also local-threshold.  
For Gimp 3.2 threshold is a layer effect (fx) which can affect subsequent filters. You might need to "apply" and lose the (fx)

Off topic but might come in useful. The gmic-gimp-qt plugin has a nice "Stamp" filter that works at any resolution.