pdfout.sh

pdfout.sh

# https://ghostscript.com/docs/9.54.0/VectorDevices.htm#
# Presets (Not recommended as it sets too many properties)
# -dPDFSETTINGS=/screen (screen-view-only quality, 72 dpi images)
# -dPDFSETTINGS=/ebook (low quality, 150 dpi images)
# -dPDFSETTINGS=/printer (high quality, 300 dpi images)
# -dPDFSETTINGS=/prepress (high quality, color preserving, 300 dpi imgs)
# -dPDFSETTINGS=/default (almost identical to /screen)

# Another reference: https://stackoverflow.com/a/72974400/10926869 (include a cmdline )

# Great images but large size
#   -dAutoFilterColorImages=false -dColorImageFilter=/FlateEncode \

# Use QFactor to change JPEG quality https://stackoverflow.com/a/49334424/10926869
#   Somehow it is not working, gs seems not reading the QFactor. The only way to set seems to be using dPDFSETTINGS

# Prefer using this version to avoid strange issues that characters are missing in some files
#   docker run --rm -v `pwd`:/app -w /app minidocks/ghostscript:9 \

DPI=600
gs -sDEVICE=pdfwrite -sOutputFile=output.pdf \
    -dCompatibilityLevel=1.7 -dFastWebView=true \
    -dEmbedAllFonts=true -dSubsetFonts=true -dCompressFonts=true \
    -dDetectDuplicateImages=true -dDoThumbnails=false -dAutoRotatePages=/None \
    -r$DPI -dColorImageResolution=$DPI -dGrayImageResolution=$DPI -dMonoImageResolution=$DPI \
    -dDownsampleColorImages=true -dColorImageDownsampleType=/Bicubic -dColorImageDownsampleThreshold=1.0 \
    -dDownsampleGrayImages=true -dGrayImageDownsampleType=/Bicubic -dGrayImageDownsampleThreshold=1.0 \
    -dDownsampleMonoImages=true -dMonoImageDownsampleType=/Subsample -dMonoImageDownsampleThreshold=1.0 \
    -dColorImageFilter=/DCTEncode -dGrayImageFilter=/DCTEncode -dMonoImageFilter=/CCITTFaxEncode \
    -dColorConversionStrategy=/LeaveColorUnchanged -dPassThroughJPEGImages=true \
    -dUseArtBox -dNEWPDF=true -dNOPAUSE -dBATCH -dSAFER \
    -dPDFSETTINGS=/printer \
    -c '<< /ColorACSImageDict << /VSamples [ 1 1 1 1 ] /HSamples [ 1 1 1 1 ] /QFactor 0.15 /Blend 1 /ColorTransform 1 >> >> setdistillerparams ' \
    -f input.pdf