Re: get image resolution

Thanks, that did get me there in the end :-)

For anyone else trying to figure this out ...

When you have converted a binary jpeg file into a hex string, the
resolution info should be encoded in a JFIF header and can be found as
follows:
look for 5 bytes 4A46494600 (this translates as ascii JFIF0)
this is followed 2 bytes of version number (usually 0101)
then 1 byte indicating inches or cm (01 or 02)
then 2 bytes for horizontal pixel density (dots per inch/cm)
then 2 bytes for vertical pixel density (dots per inch/cm)