3 Replies Latest reply: Oct 10, 2012 10:51 AM by user8668882 RSS

    SI_StillImage matching performance


      I'm developing an image matching system for a test set of 1000 images using SI_StillImage but keep hitting performance issues. As an example, when I first run the query below, it executes in around 60 seconds. The second run takes about twice as long and subsequent runs take progressively longer.
      SELECT b.image_id, 
                 SI_AverageColor(a.image),    35/100,
                 SI_ColorHistogram(a.image),  21/100,
                 SI_PositionalColor(a.image), 45/100,
                 SI_Texture(a.image),         10/100
      FROM images a, images b
      WHERE a.image_id = 1
      ORDER BY score ASC
      I've had similar issues with simpler matching, e.g. just using average color, which I've overcome by generating a table of results with pair wise image comparison scores in advance to use as a cache, but I can't do that in this case as ultimately, I'd like users to be able to specify the weights for each feature interactively.

      I've a similar system in the past based on ORDImage signatures using the built-in indextype which worked really quickly in comparison but SI_StillImage doesn't have that option.

      Any ideas?



      Oracle Database 11g Enterprise Edition Release - 64bit Production
      Windows 2008 R2 Server with 16Gb RAM available for Oracle