First up, what type of bar code are you talking about, a simple 3of9 or the more complex 2D bar codes also how does your bar code reader connect to the computer via the PS2 keyboard port or USB, does it have specific drivers and will those drivers interact with a browser.
When you store a bar code you do not store the image that you see but the alphanumeric characters that make up the bar code, so if you have a bar code that corresponds to ABC1234 then that is what is stored and retrieved from the database.
As for displaying the bar code if you are using the 3of9 bar code then you could use a
free 3of9 bar code font[
^] installed on the web server and the Graphics DrawString function to create an image of the text, which you can then display on a web page.