Check the statistics, index fragmentation.  In anycase, if you store image in Database , then the performance will hit. If you have removed all the images from the db and then also its slow then , it may be because of Fragmentation,statistcs are not updated and also indexes are outdated.

Run

(a) sp_updatestats

(b) DBCC DBREINDEX (its a offline process and it will lock the tables)

(c) check the space used by the database. you may need to shrink the db, incase there is drastic difference in actual data stored and the physical size of the file

Note : Store the image filename in the database instead of the image itself.

(d) move indexes on separate filegroups

Refer these links:

http://www.sql-server-performance.com/forum/topic.asp?TOPIC_ID=19594

http://www.sql-server-performance.com/forum/topic.asp?TOPIC_ID=19595