> >Where do I get a how-to for writing blob filters?
>
>As far as I know the only documentation is in the API guide.
>The filter itself is just a UDF that takes a blob of one
>type as input and returns a blob of another type.

I suggest in the source code lurking about are the system BLOB filters
waiting to be learned from.

In IB_WISQL there is the spot where BLR blobs are coerced as TEXT and by
this it invokes a BLOB filter to convert the BLR to human readable TEXT. I
had to jerry rig it so that there were CRLF pairs after each line but it
works like a champ.

FWIW,
Jason Wharton
CPS - Mesa AZ
http://www.ibobjects.com