I am trying to read the BLOB data present in database and transforming it to generate image. The data table when imported into jmp shows the BLOB field as empty. The blob field is stored in the database correctly
Have you looked under Help > Scripting Index and searched for "blob"? In particular, the LoadTextFile() function supports BLOBs, and can even read substrings from BLOBs.
I'm sorry, but BLOB data import is not supported in the JMP ODBC interface. JMP ignores the BLOB because it doesn't know how it should be interpreted.