SD Ruby, I'm looking for a solution to a search problem and want to survey the community to see if anyone else has dealt with this type of search.
The application I'm building supports an image processing system. We have a mathematical way of uniquely representing any particular image as a vector of 16 values, each ranging between 0 and 255. I need to implement a search mechanism that finds the closest matches to a given image, also represented as a 16 element vector. This is usually called a "vector space model" search, and it's implemented for full text search in Postgres as well as Lucene, and probably many other full text search systems. The problem I'm wrestling with is I'm not searching on text, I'm searching on integers. I basically need to search for the closest match like this: Say my search image has a vector with elements q(1) to q(16), [q(1) = 122, q(2) = 7, q(3) = 89,, ..., q(16) = 224]. To compare that vector against the image vectors in the database I need to calculate the "distance" between the query vector (q) and each of the database vectors (d): distance = square_root( (q(1) - d(1))^2 + (q(2) - d(2))^2 + ... (q(16) - d(16))^2) The lower the distance the closer the match, with dist == 0 being an exact match. My research hasn't led me to a direct implementation of this in Postgres or Lucene since they are designed for text searching, though the underlying principles are the exact same. Anyone ever tackle this type of search with numerical values? Thanks in advance, Chris -- -- SD Ruby mailing list [email protected] http://groups.google.com/group/sdruby --- You received this message because you are subscribed to the Google Groups "SD Ruby" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
