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static Vector4 LinearToXyz (in Color c)
{
    // This could also be written as matrix-vector multiplication.
    // Perceptual luminance is the y component.
    return new Vector4 (
        0.41241086f * c.r + 0.35758457f * c.g + 0.1804538f * c.b,
        0.21264935f * c.r + 0.71516913f * c.g + 0.07218152f * c.b,
        0.019331759f * c.r + 0.11919486f * c.g + 0.95039004f * c.b,
        c.a);
}

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byte[ ] stlLut = new byte[256];
byte[ ] ltsLut = new byte[256];

for (int i = 0; i < 256; ++i)
{
    float x = i / 255.0f;
    float y = StandardToLinearChannel (x);
    stlLut[i] = (byte) (0.5f + 255.0f * y);
    float z = LinearToStandardChannel (x);
    ltsLut[i] = (byte) (0.5f + 255.0f * z);

behreajj

using UnityEngine;

[RequireComponent (typeof (SpriteRenderer))]
public class Grayscale : MonoBehaviour
{
    void Start ( )
    {
        SpriteRenderer renderer = GetComponent<SpriteRenderer> ( );
        Sprite sprite = renderer.sprite;
        Texture2D srcTexture = sprite.texture;

behreajj

static float StandardToLinearChannel (in float x)
{
    return x > 0.04045f ?
        Mathf.Pow ((x + 0.055f) / 1.055f, 2.4f) :
        x / 12.92f;
}
    
static float LinearToStandardChannel (in float x)
{
    return x > 0.0031308f ?

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static float GrayLumIncorrect (in Color srgb)
{
    return 0.21264935f * srgb.r + 0.71516913f * srgb.g + 0.07218152f * srgb.b;
}

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static float GrayHsl (in Color c)
{
    return 0.5f * (Mathf.Max (c.r, c.g, c.b) +
        Mathf.Min (c.r, c.g, c.b));
}

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static float GrayHsv (in Color c)
{
    return Mathf.Max (c.r, c.g, c.b);
}

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static float GrayAverage (in Color c)
{
    return (c.r + c.g + c.b) / 3.0f;
}

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dofile("./sRgbToAdobeRgb.lua")

local dlg = Dialog { title = "SRGB - Adobe Convert" }

dlg:button {
    id = "palAdobeToSrgb",
    text = "Pal &Adobe to sRGB",
    onclick = function()
        local sprite = app.activeSprite
        if sprite then

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-- Ported from the Python code of Mark Ransom
-- https://stackoverflow.com/a/40231268
-- For more on the magic numbers, see
-- http://brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html

ColorConvert = {}
ColorConvert.__index = ColorConvert

setmetatable(ColorConvert, {
    __call = function (cls, ...)