PHP Interbase or Firebird database JPEG output

I am using the PHP 4.3.4 with a standard (unmodified ) php.ini file.
I am tryong to output a blob field that contains a jpeg image using
the ibase_blob_echo( row[3]) function. I am presently outputting the
output of three fields o text from the database. I want to add a
fourth output field that contains a jpeg image that is stored in the
database. What HTML or php functions should I specify to output this
image into the users web browser? Any samples would be appreciated.