This is a sinatra app that pulls some content from postgres. Notably it uses "PGconn.unescape_bytea" to compensate for Postgres's greedy escape_bytea which causes no end of pain.
! send_data is depricated
At first this is what I thought was the problem, but it was actually postgres driver in datamapper. So if you run into a problem of not being able to pull an image out of a postgres bytea then maybe this will help.
! Testing if you got image
If you have a byte aray in postgres holding your image data, here is how you can pull it out the hard way: Log into psql and do this:
\copy (select encode(data, 'hex') from images where id=5) TO '/Users/yourname/Desktop/image.hex';
That should make a hex version of the file. Then in terminal simply run:
xxd -p -r image.hex > image.jpg