Custom fields do not support BLOBs, so doing this as a proper image is out of the question. However, I was able to develop a work-around using a text field, in Code 39, using Unicode characters for the fat and thin bars.

First, create a custom package. (See attached for C_BARCODE_API. You may need to edit the grants.)

Next, create a custom field, read-only, of type “Expression”. In this example, the barcode shows the order number on a Shop Order.

c_barcode_api.alphanum_to_code39(v.order_no)

Idea: push the image in a sticky note
Not that easy, but it would contain possibly the following steps:
Create a barcode image of the key object (ie. shop order number and sticky note will contain barcode of the number)
Insert a row in fnd_note_book
Insert a row in fnd_not_page with the note_id as prepared for fnd_note_book. The note text will contain the image.

There are several web services available that can be called from Oracle to pull down a BLOB of a barcode image.

You can store the BLOB image in the sticky note, but the image needs to be converted to an RTF format if you want it displayed as an image/picture.

I like the idea of the project, but it would take some research to find a BLOB to RTF conversion utility for Oracle (unless someone has one handy).

Here’s an open-source PL/SQL package that outputs a barcode image:

https://github.com/antonscheffer/as_barcode

(Its license is permissive, provided the attribution notice is retained.)

Why not add this as document attachment? APIs are available and fairly simple to use..

Alternatively attach as media attachment.

https://github.com/durette/CCode39Barcode