Though note that this uses j2k by default and jpegoptim for JPEGs. For pages that are mostly just images (e.g. color comics) I prefer to use cjpegli on each page and img2pdf to combine them to a PDF.
Modifying archive-pdf-tools to allow use of cjpegli is something I keep meaning to look into[1], but not at the top of my list.
1: In my tests, cjpegli is more consistent than j2k compressors; that is, for each image there is a setting that j2k does as good, or better, than JPEG, but there is no setting for which j2k averages better than cjpegli because cjpegli just does such a good job of aggressively compressing while always looking good
Though note that this uses j2k by default and jpegoptim for JPEGs. For pages that are mostly just images (e.g. color comics) I prefer to use cjpegli on each page and img2pdf to combine them to a PDF.
Modifying archive-pdf-tools to allow use of cjpegli is something I keep meaning to look into[1], but not at the top of my list.
1: In my tests, cjpegli is more consistent than j2k compressors; that is, for each image there is a setting that j2k does as good, or better, than JPEG, but there is no setting for which j2k averages better than cjpegli because cjpegli just does such a good job of aggressively compressing while always looking good