scala shit

gistfile1.scala

def dominantOri(hist: Histogram) = {
  hist.reduceLeft ( _ max _ )
}

def goodOriFeatures(hist: Histogram, magThr: Double, feat: Feature) = {
  val n = hist.length
  def isGoodP(i: Int) = {
    val l = if (i == 0) n - 1 else i - 1
    val r = (i + 1) % n

    hist(i) > hist(l) && hist(i) > hist(r) && hist(i) >= magThr
  }

  for(i <- 0 until n
      if isGoodP(i)) yield {
    val l = if (i == 0) n - 1 else i - 1
    val r = (i + 1) % n
    val bin = i + interpHistPeak( hist(l), hist(i), hist(r) )
    val bin2 = {
      if ( bin < 0 ) n + bin
      else if ( bin >= n ) bin - n
      else bin }
    val ori = ((Math.PI * 2 * bin) / n) - Math.PI
    Feature(feat.dd, feat.x, feat.y, feat.scl, ori)
  }
}

def normalizeDescr(descr: Histogram) = {
  val lenSq = descr foldLeft(0)((x y) => x*x + y)
  val ledInv = 1.0 / Math.sqrt(lenSq)

  feat.descr map (x => x * lenInv)
}

def featureCmp(f1: Feature, f2: Feature) = {
  if (f1.scl < f2.scl)
    1
  else if (f1.scl > f2.scl)
    -1
  else
    0
}

def histToDescr(hist: Histogram, d: Int, n: Int, feat: Feature) = {
  val flat = hist.flatMap(x => x).flatMap(x => x).flatMap(x => x)
  val normed1 = normalizeDescr(flat)
  val clipped = normed1.map(x => { if( x > SIFT_DESCR_MAG_THR )
                                     SIFT_DESCR_MAG_THR})
  val normed2 = normalizeDescr(clipTop)
  val intHist = normed2.map(x => min(255, (x * SiftIntDescrFctr).toInt))

  Feature(feat.dd, feat.x, feat.y, feat.scl, feat.ori, intHist)
}