Lab Channels

ab Channels converts your photograph into CIE L*a*b* and lets you work the three channels separately. In RGB, brightness is baked into every channel. Turn down red and the picture gets darker as well as less red — the two cannot be separated. Lab splits them apart. One channel carries all the tone. Two carry all the colour: one running green to magenta, the other blue to yellow. That separation is the point. It lets you change colour without touching brightness, or brightness without shifting a single hue. WHAT YOU CAN DO • View any channel on its own as greyscale • Invert, brighten, or add contrast to each channel independently • Swap the two colour channels to rotate every hue at once • Threshold the tone channel down to pure black and white • Stack copies of the photo and blend them together • Choose how colour that falls outside your screen's range is handled WORKING WITH CHANNELS…