constexpr Channel RGB_CHANNELS[] = {RED, GREEN, BLUE};
constexpr Channel BGR_CHANNELS[] = {BLUE, GREEN, RED};
constexpr Channel RGBA_CHANNELS[] = {RED, GREEN, BLUE, ALPHA};
constexpr Channel RGB_CHANNELS[] = {RED, GREEN, BLUE};
constexpr Channel BGR_CHANNELS[] = {BLUE, GREEN, RED};
constexpr Channel RGBA_CHANNELS[] = {RED, GREEN, BLUE, ALPHA};