Hello everyone, i have tried to scan an old postcard.
How can i get rid of the print “effect”? In Italy i call it retinatura, maybe it’s called halftone printing in english.
here you can find the scan: SwissTransfer.com - Envoi sécurisé et gratuit de gros fichiers
Thank you in advance.
Thank you, i have tried by hand with g’mic fft and after with the g’mic repair-descreen plugin that in a click does the same and maybe even better!
Hello, I use G’mic descreen for that, works fine for scans of printed materials.
On the picture below: left original scan, right after descreening, both at 100%.
yes it’s the one i mentioned.
btw, how do i call it from commandline gimp? I have almost never use gmic from commandline, but haven’t found a way to call this particular filter.
In the GIMP, I applied 2.5 px Gaussian Blur, downsized 50% cubic, up sized 200% cubic, voila
Effect reduced but not “got rid of”
full size here: http://kronometric.org/phot/temp/CartolinaCaviLavagna-Viaggiata1968%20gimp%20Ted.jpg
From the commandline, it used to be ‘fx_pahlsson_descreen’.
But when I use this now, with a newer version of gmic, it says
[gmic]-1./ *** Error *** Unknown command or filename ‘fx_pahlsson_descreen’.
When I use this filter from Gimp and say ‘copy command to clipboard’, it outputs exactly the above string.
So we must ask @David_Tschumperle what’s going on…
The difference between the command line tool and the GIMP plug-in is that the CLI tool does not embed the gmic-community filters by default.
fx_pahlsson_descreen is a command defined in the community filters.
$ gmic update allows to get this command back in the CLI tool.
Thanks David, that worked!
ggc, here’s the command to descreen your postcards in batch, assuming you store them in a folder called postcards :
cd ~/postcards
for i in *
do
gmic input $i fx_pahlsson_descreen 0 output descreen_$i
done
exit
That is exactly what i wanted to do, thank you!
You’re welcome !
You can also achieve good results with the following filters in GIMP with G’MIC:
G’MIC>Testing>Iain Fergusson>Iain Remove Pattern
and
G’MIC>Repair>Unstrip
You can optionally combine the results of both filters with Layers in GIMP.
