u can store images of any format by using lob data types
step1:first create a table with field type as BFILE,BLOB
eg:create table img(imgno number,imgo BFILE,imgi BLOB)
step2:using DBMS_LOB package load the picture into the BFILE field
Step 3:Using the DBMS_LOB.LOAD() u load the bfile field into BLOB field
step 4:To retrieve the image from database to front end it is possible only with forms6i.
regarding the actual coding please visit the site of oracle
doc umentation there u have a book on dealing with images using visual cartridge.
prior to this u should have oracle 8 with visual cartridge installed on it(optional)handing will be easy