greyedColor = function(colr)
	clist = color.toList(colr)
	lum = [0.2126, 0.7152, 0.0722]
	
	red = clist[0] * lum[0]
	green = clist[1] * lum[1]
	blue = clist[2] * lum[2]
	grey = red + green + blue
	return color.fromList([grey, grey, grey, clist[3]])
end function

toGreyScale = function(img)
	greyImg = Image.create(img.width, img.height)
	for x in range(0, img.width - 1)
		for y in range(0, img.height - 1)
			greyed = greyedColor(img.pixel(x, y))
			greyImg.setPixel x, y, greyed
		end for
	end for
	return greyImg
end function

clear

// The turtle and color wheel images are included with MiniMicro
turtle = file.loadImage("/sys/pics/animals/turtle.png")
greyTurtle = toGreyScale(turtle)
gfx.drawImage turtle, 0, 0
gfx.drawImage greyTurtle, turtle.width, 0

colorWheel = file.loadImage("/sys/pics/ColorWheel.png")
greyWheel = toGreyScale(colorWheel)
gfx.drawImage colorWheel, 0, 320
gfx.drawImage greyWheel, greyWheel.width, 320