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Split a PNG into LAB Channels

L (lightness) · a (green–red) · b (blue–yellow) · grayscale per channel · ZIP

Convert an image into its CIELAB components — Lightness (L) and the two opponent-colour channels a and b — each as a grayscale PNG. LAB is a perceptually-uniform model designed to match how humans see colour differences. Drop a file and download the channels as a ZIP, processed in your browser.

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    What each channel is

    Why LAB is special

    Unlike RGB, LAB is perceptually uniform: a numeric distance between two colours roughly matches how different they look to the eye. That makes the L channel ideal for brightness edits that don't shift colour, and a/b useful for colour-based selection and matching. The conversion here assumes an sRGB source under a standard D65 white point.

    FAQ

    Why do the a and b channels look mostly gray?

    They're centred on neutral (mapped to mid-gray) and only move toward white or black where a colour leans strongly green/red or blue/yellow. Muted images stay near the middle.

    Is the L channel the same as grayscale?

    Very close — L is the most perceptually accurate lightness there is, so it's an excellent black-and-white. Our Grayscale tool uses a simpler luma formula that's near-identical for most images.

    Part of: Get pixel values out in another colour space

    Pick by what the receiving code expects: HSL to reason about hue, LAB for perceptual distance, YCbCr for video, CMYK for print.

    1. 1 PNG to HSL Hue, saturation, lightness — the one for CSS
    2. 2 PNG to LAB Perceptually uniform, for measuring colour difference
    3. 3 PNG to YCbCr Luma and two chroma planes, as video codecs see it
    4. 4 PNG to CMYK The four ink plates a press will actually lay down

    All 28 step-by-step workflows