OK, I'll answer my own question: Firstly, when I loaded a fresh copy of the wiki into node.js, the png images appeared in the tiddlers directory in their native png format along with an associated .meta file. I guess I had loaded the previous copy from an earlier version of Tiddlywiki that behaved differently.
Then to convert embedded png images to jpg format, I created a bash script that stepped through all the png files and converted them to jpg files, edited and renamed the associated .meta files and then ran a search and replace on all the tiddlers to replace references to the old .png files with the updated .jpg files. This reduced my wiki file size from 73MB to 26MB - much more manageable. I'm sure there are much more elegant ways to do this, but this solved my immediate problem. Mal -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to tiddlywiki+unsubscr...@googlegroups.com. To post to this group, send email to tiddlywiki@googlegroups.com. Visit this group at https://groups.google.com/group/tiddlywiki. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/da49ceae-72cd-4c2e-a294-bcc7eec5198a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
