Enlarge an Image

def grow (source):
  #set up target picture
  target = makeEmptyPicture( getWidth(source) * 2, getHeight(source) * 2)
 
  #do the actual copying
  sourceX = 0
  for targetX in range (0, getWidth(source) * 2):
    sourceY = 0
    for targetY in range (0, getHeight(source) * 2):
      color = getColor (getPixel (source, int(sourceX), int(sourceY)))
      setColor (getPixel (target, targetX, targetY), color)
      sourceY = sourceY + 0.5
    sourceX = sourceX + 0.5
  return (target)