Extract colour gradient pixel information

Question

I am attempting to control a 240 long line of RGB pixels (ws2812b) using an artnet to dmx controller and need to generate colour gradients down the length of the line of pixels.

Answer 1

Here is a function that takes a list of stop colors and returns a list of evenly interpolated colors:

List interpolateColors(List stopColors, int count)
{
    List ColorList = new List();

    using (Bitmap bmp = new Bitmap(count, 1))
    using (Graphics G = Graphics.FromImage(bmp))
    {
        Rectangle bmpCRect = new Rectangle(Point.Empty, bmp.Size);
        LinearGradientBrush br = new LinearGradientBrush
                                (bmpCRect, Color.Empty, Color.Empty, 0, false);
        ColorBlend cb = new ColorBlend();

        cb.Colors = stopColors.ToArray();
        float[]  Positions = new float[stopColors.Count];
        for (int i = 0; i < stopColors.Count; i++) 
              Positions [i] = 1f * i / (stopColors.Count-1);
        cb.Positions = Positions;
        br.InterpolationColors = cb;
        G.FillRectangle(br, bmpCRect);
        for (int i = 0; i < count; i++) ColorList.Add(bmp.GetPixel(i, 0));
        br.Dispose();
    }
    return ColorList;
}

You could call it as:

List ColorList = interpolateColors(
                        new List{Color.Red, Color.Blue, Color.Yellow}, 240);

240 and 740 colors. To get all distinct colors make sure they are not too many and not too close, as the maximum number of RGB hues between two colors is 256, so the second example may hit that limit..