#Here we brighten a picture.  The idea is
#to multiply each pixel value by 1.5.  To
#avoid going over 255, we take the minimum
#of the increased pixel value and 255.
def brighten():
  pic=makePicture(pickAFile())
  for px in getPixels(pic):
    setRed(px,min(255,1.5*getRed(px)))
    setBlue(px,min(255,1.5*getBlue(px)))
    setGreen(px,min(255,1.5*getGreen(px)))
  writePictureTo(pic,"/Users/straubin/home/CS074-09/brighter.jpg")