def changeBrightness(pic):
 show(pic)
 x=requestInteger('Percentuale di luminosità')
 for p in getPixels(pic):
    r=getRed(p)+(getRed(p)*x/100)
    g=getGreen(p)+(getGreen(p)*x/100)
    b=getBlue(p)+(getBlue(p)*x/100)
    newColor=makeColor(r,g,b)
    setColor(p, newColor)
 repaint(pic)