applyWindowFunction

applyWindow.hs

{-# RULES
    "applyWindow/applyWindow" forall win1 win2 image. applyWindow win1
                                                                  (applyWindow win2 image) =
                                                                  applyWindow (indexMult win1 win2) image
  #-}

applyWindow  window imageArray =
  let ((windowWidthMin, windowHeightMin), (windowWidthMax, windowHeightMax)) = bounds window -- keep
      windowWidth = windowWidthMax - windowWidthMin  -- Keep Calculated
      windowHeight = windowHeightMax - windowHeightMin -- Keep Cakculated
      w = (floor (fromIntegral(windowWidth) / 2)) :: Int -- Keep
      h = (floor (fromIntegral(windowHeight) / 2)) :: Int -- Keep
      ((imageWidthMin, imageHeightMin), (imageWidthMax, imageHeightMax)) = bounds imageArray -- Keep
      paddedImage =
        array
        ((imageWidthMin-w,imageHeightMin-h),(imageWidthMax+w,imageHeightMax+h))
        [ ((i,j), if i >= imageWidthMin &&
                     j >= imageHeightMin &&
                     i <= imageWidthMax &&
                     j <= imageHeightMax
                  then imageArray ! (i,j)
                  else 0
          ) |
          i <- [imageWidthMin-w..imageWidthMax+w],
          j <- [imageHeightMin-h..imageHeightMax+h]]
      filteredPaddedImage  = {-# SCC "filter" #-}
        array
        ((imageWidthMin-w,imageHeightMin-h),(imageWidthMax+w,imageHeightMax+h))
        [((i,j), if i >= imageWidthMin &&
                    j >= imageHeightMin &&
                    i <= imageWidthMax &&
                    j <= imageHeightMax
                 then {-# SCC "sum" #-} sum  [{-# SCC "list" #-} ((paddedImage!(i+m,j+n)) * window!(m,n)) |
                                             m <- {-# SCC "m" #-} [windowWidthMin..windowWidthMax],
                                             n <- {-# SCC "n" #-} [windowHeightMin..windowHeightMax]]
                 else 0
         ) |
         i <- [imageWidthMin-w..imageWidthMax+w],
         j <- [imageHeightMin-h..imageHeightMax+h]]
  in array -- Is this necessary?  or can we just return filteredPaddedImage
     ((imageWidthMin, imageHeightMin), (imageWidthMax, imageHeightMax))
     [((i,j), (filteredPaddedImage!(i,j)) ) |
      i <- [imageWidthMin .. imageWidthMax],
      j <- [imageHeightMin .. imageHeightMax]]