Ghostscript gs - create pdf from pdf or other type, how to convert patterns to bitmaps and keep all other bitmaps dpi's untouched

It seems that dPDFSETTINGS=/screen    has an hidden option to convert patterns to bitmaps, problem is that with this the images are downsamsampled, to get around this do:-

(this converts patterns to bitmaps as 600dpi)

"C:\Program Files\gs\gs9.02\bin\gswin32c.exe" -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dQUIET   -dPDFSETTINGS=/screen -dDownsampleColorImages=false -dDownsampleGrayImages=false -dDownsampleMonoImages=false -r600 -dEmbedAllFonts=true -dOptimize=true -sOutputFile="out-test.pdf" "test.pdf"