[fprint] conversin of fprint data to store in database

[Daniel Drake]

Alexander Eichert wrote:
> Yes, the enroll-program stores one fingerprint in a blob-field within 
> the mysql db after the fingerprint is converted by "fp_print_data_get_data".
> 
> The verify-program retrieves all fingerprints stored in the database, 
> reconverts them to an fp_print_data-struct with 
> "fp_print_data_from_data" and then searchs a match in these fingerprints 
> for a new scanned fingerprint.
> 
> But, at the moment, reconversion with "fp_print_data_from_data" fails.
> 
> I have tested to convert and reconvert the fingerprint-data in the 
> enroll-program as Daniel mentioned. That works.

OK, so this suggests a problem with your storage or retrieval code.

How about trying this:
When you get the buffer from libfprint using fp_print_data_get_data(), 
dump it to a file (as binary data). And also write it into your database.

When you later retrieve it from the database, before you pass it to 
fp_print_data_from_data(), dump *that* data to another binary file.

Then you will have 2 binary files that you can compare. Are they 
identical? (They should be, there is no reason for the data to have changed)

Daniel