Compressing text heavy PDFs without ghostscript and only ImageMagik causes blurry text - pdf

Question

I am trying to compress PDF versions of my school newspaper using code and created the following script which works perfectly below.
gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -sOutputFile=$file $old;
I went to run it on the server and discovered that the version of ghostscript on my server was old causing the code to not work, and I don't have permission to update gs (I'm on a shared hosting service.) I do have ImageMagik on the server too and was wondering if anyone could help me compress text heavy PDFs with it. I tried some code similar to
convert -compress JPEG -quality 100 input.pdf output.pdf
but it made the PDF text very blurry (not good for reading newspapers.)
If anyone could help me, it would be greatly appreciated. Thank you!

Answer 1

ImageMagick also uses Ghostscript to convert your pdf file and it will use the same old version of Ghostscript.
If you want to get a more readable text you should set the density.
convert -density 150 input.pdf -compress JPEG output.pdf
If you want to get images with a higher quality you should not specify JPEG compression. If your PDF is monochrome you can use Group4 compression:
convert -density 150 input.pdf -compress group4 output.pdf
When your PDF is not monochrome you can use LZW/Zip compression:
convert -density 150 input.pdf -compress LZW output.pdf
convert -density 150 input.pdf -compress Zip output.pdf
You could start with 150 and increase it to improve the quality. But that will also increase the size of your file. ImageMagick will convert your pdf to an image and then convert it back to a PDF file that contains only images and not text. I am not sure if this will actually decrease the size of your file but you will have to test that yourself.