Image processing with BLOBS: how to write BufferedImage to a BLOB

Question

Hi everybody - thanks in advance for any input on that topic.
I'm doing image processing using AWT and 2D. Images are stored in a RDBMS as BLOB Type, which I get using JDBC and convert to a BufferedImage using a JDBCImageDecoder.
Now, I have my BufferedImage and I can process them using the appropriate filters (ConvolveOp e.g.)
Writing the BufferedImages to disk or display on screen is easy. But I can't get to write them to a BLOB Object. Any Hint ?
(Of course, I'm speaking of oracle.sql.BLOB objects, not java.sql.Blob).
Thanks and have a nice day

Answer 1

Billy,
Thank you for your answer. I have two questions.
First what that means "Bob's your uncle ?" I'm a french man, not used to english special sentences ou jargon. Would enjoy to know !
Second, I have created a PL/SQL procedure to update my table. I face a problem.
I want to initialize b_lob with the img_blob value but I get an error : "ORA-22922: nonexistent LOB value". WHere do my error comes from ? I am fairly new in this stuff of BLOB.
Below my procedure.
Thank for your kind help.
Christian.
create or replace
procedure insert_img as
f_lob bfile;
b_lob blob;
loops number default 0 ;
lines number default 0;
stmt varchar2(4000);
cursor c1 is select img_blob, file_name, pk from photos FOR UPDATE ;
begin
NULL;
dbms_output.enable(900000);
stmt := 'SELECT COUNT(*) FROM PHOTOS';
EXECUTE IMMEDIATE stmt INTO LINES ;
for ligne in c1 loop
exit when loops >= lines ;
loops := loops+1;
update photos set img_blob= empty_blob() where CURRENT OF C1;
-- return img_blob into b_lob;
b_lob := ligne.img_blob ;
f_lob := bfilename( 'MY_FILES', ligne.file_name );
IF (DBMS_LOB.FILEEXISTS(f_lob) != 0)
THEN
      DBMS_OUTPUT.PUT_LINE('BFILE exist: '|| ligne.file_name || ', ligne :'|| ligne.pk);
      dbms_lob.fileopen(f_lob, dbms_lob.file_readonly);
      dbms_lob.loadfromfile( b_lob, f_lob, dbms_lob.getlength(f_lob) );
      dbms_lob.fileclose(f_lob);
      dbms_output.put_line('ligne.pk :' || ligne.pk || ', lines : ' || lines || ', loops ' || loops);
  ELSE
    DBMS_OUTPUT.PUT_LINE('BFILE does not exist: '|| ligne.file_name || ', ligne :'|| ligne.pk);
  END IF;
end loop;
commit;
end insert_img;