Downsize PDF file to lower resolution on MacOS

I exported a image to a PDF in the file->print menu of the photo app of MacOS. The problem is, the image was saved as original resolution thus the PDF file is way too huge. I need to lower the resolution to something like 150DPI. I serach for a while and found those 2 solutions which I love best 1. Use GhostScript https://blog.omgmog.net/post/compressing-pdf-from-your-mac-or-linux-terminal-with-ghostscript/ 2. Quartz Filters. If you do not like command line, download the filter files from https://github.com/joshcarr/Apple-Quartz-Filters Then sudo mkdir /Library/Filters sudo mv *.qfilter /Library/Filters the open PDF file in preview, File->Export, you'll be able to choose a quartz filter