Application creates PDF file using Infotec PS printer driver and 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 is bigger and it is shrinked in pdf to creeate smaller logo. Image has single color.
Image in pdf appears dirty and there are pixels with other colors:

https://i.stack.imgur.com/9ygEm.png

How to fix this so that image appears sharp and contians only sinle color ?
Is it possible to change some Ghostscript printer diver settins or windows PS printer driver settings?

Original image is bigger and has good quality.

https://i.stack.imgur.com/y9oke.jpg

Posted also in

http://stackoverflow.com/questions/40657349/how-to-render-charp-image-in-pdf-using-ghostscript

If XFRX is used, image quality is good in PDF