Cynosphere

local function RGBToYCbCr(r, g, b)
    local Y  =  0.299 * r + 0.587 * g + 0.114 * b
    local Cb = -0.169 * r - 0.331 * g + 0.500 * b + 128
    local Cr =  0.500 * r - 0.419 * g - 0.081 * b + 128

    return Y, Cb, Cr
end

local function YCbCrToRGB(Y, Cb, Cr)
    local r = 1 * Y + 0 * (Cb - 128) + 1.4 * (Cr - 128)