printing - How to render charp image in pdf using Ghostscript -

visual foxpro application creates pdf file using infotec ps printer driver , ghostscript 9.20 using gsdll32.dll

with parameters

-dnopause -dbatch -dsafer -dpdfsettings=/screen -r300 -sdevice=pdfwrite -soutputfile=file.pdf -c .setpdfwrite -f inputfile.ps 

pdf contains image image size bigger , shrinked in pdf creeate smaller logo. image has single color. image in pdf appears dirty , there pixels other colors.

how fix image appears sharp , contians sinle color ? possible change ghostscript printer diver settins or windows ps printer driver settings.

original image bigger , has quality.

firstly, don't use -dpdfsettings=/screen. intended reduce file sizes suitable screen resolution, sets whole host of configurations. better far understand doing , select ones want change.

now quite image has been quantised (ie has been turned jpeg), , flat coloured images unsuitable candidates jpeg compression relies on image being photographic (jpeg = joint photographic experts group).

if don't want images compressed jpeg you'll have alter colorimagefilter, covered in documentation.

as i've mentioned other people recently, belief artifex (the copyright owners) regard linking ghostscript dll 'derivative work' under agpl , need make source application open-source, or seek commercial licence.