gistfile1.txt

#!/usr/bin/env ruby
require 'hornetseye'
include Hornetseye
class Sequence_
  def avg
    sum / size
  end
  def sqr
    self * self
  end
  def corr( other )
    ( rfft * other.rfft.conj ).irfft
  end
  def zcorr( other )
    zother = MultiArray.dfloat( *shape ).fill!
    zother[ 0 ... other.shape[0], 0 ... other.shape[1] ] = other
    corr zother
  end
  def median( *shape )
    filter = MultiArray.dfloat( *shape ).fill! 1
    zcorr filter
  end
  def ncc( other, noise )
    zcorr( other - other.avg ) /
      Math.sqrt( ( sqr.median( *other.shape ) -
                   median( *other.shape ).sqr / other.size ) *
                 ( other - other.avg ).sqr.sum + noise )
  end
end
raise "Syntax: ./findnumbers.rb <input image> <number image>" if ARGV.size != 2
image = MultiArray.load_ubytergb(ARGV[0])
template = MultiArray.load_ubytergb(ARGV[1])
debugger
ncc = image.to_dfloat.ncc(template.to_dfloat, 0.1)
idx = MultiArray.int(*ncc.shape).indgen!.mask(ncc >= ncc.max)[0]