Delegate RowBandAction

Namespace

Egami.Operations

Assembly

Egami.dll

Processes a band of rows: rows start (inclusive) to end (exclusive).

public delegate void RowBandAction(int start, int end)

Parameters

start int

The first row.

end int

The row just past the last one.

Examples

/// <summary>Black or white per pixel: ForEachBand gives each worker a band of rows from start to end.</summary>
private sealed class Threshold(float level) : IRasterOperation
{
    public Size OutputSize(Size input) => input;

    public void Run<TPixel>(OperationInput<TPixel> input)
        where TPixel : unmanaged, IPixelType<TPixel>
    {
        RowBandAction band = (start, end) =>
        {
            for (int y = start; y < end; y++)
            {
                Span<TPixel> source = input.Source.Row(y), destination = input.Destination.Row(y);
                for (int x = 0; x < source.Length; x++)
                {
                    Vector4 v = source[x].ToScaled();
                    float on = ((0.2126f * v.X) + (0.7152f * v.Y) + (0.0722f * v.Z)) >= level ? 1 : 0;
                    destination[x] = TPixel.FromScaled(new Vector4(on, on, on, v.W));
                }
            }
        };
        input.ForEachBand(band);
    }
}