how to optimize BLOB access with an user defined function

I am storing BLOBs in a sqlite3 database table. The table is rather simple:

create table r (id integer primary_key asc, d blob);

I wrote some user defined functions (let's call one of them "udf()") to read specific values out of the blob. When I am using those functions like this:

select udf(100,d), udf(200,d) from r;

sqlite3 copies the data d internally (with EXPLAIN I find that the vbde creates OP_COPY instead of OP_SCOPY) without necessity. Is it possible to hint the parser to re use the column d for both calls to udf() instead of copying it (and all the blob data)) (1)?

(1) http://ift.tt/1LXoAfw states "a duplicate is made of every string or blob."