AlphaToGrayscaleFilter Class

Copies the alpha channel in the image to the color channels, resulting in a grayscale representation of the alpha channel.

Namespace: Lumia.Imaging.Compositing
Assembly: Lumia.Imaging (in Lumia.Imaging.dll) Version:


public sealed class AlphaToGrayscaleFilter : IFilter, 
Public NotInheritable Class AlphaToGrayscaleFilter
    Implements IFilter, __IAlphaToGrayscaleFilterPublicNonVirtuals
public ref class AlphaToGrayscaleFilter sealed : IFilter, 
Lumia.Imaging.Compositing.AlphaToGrayscaleFilter = function();



The alpha information is no longer present in the output.

This filter is primarily intended for conversion of an alpha based mask to a grayscale mask suitable for use with ImageFusionFilter or BlendFilter.


This sample loads image with alpha channel and applies the filter to it

using (var filterEffect = new FilterEffect(source))
    // Initialize the filter and add the filter to the FilterEffect collection
    var filter = new AlphaToGrayscaleFilter();

    filterEffect.Filters = new IFilter[] { filter };

    // Create a target where the filtered image will be rendered to
    var target = new WriteableBitmap(width, height);

    // Create a new renderer which outputs WriteableBitmaps
    using (var renderer = new WriteableBitmapRenderer(filterEffect, target))
        // Render the image with the filter(s)
        await renderer.RenderAsync();

        // Set the output image to Image control as a source
        ImageControl.Source = target;

    await SaveEffectAsync(filterEffect, "AlphaToGrayscaleFilter.jpg", outputImageSize);

Inheritance Hierarchy


Version Information

Lumia Imaging SDK

Supported in: 2.0

See Also

AlphaToGrayscaleFilter.AlphaToGrayscaleFilter Members

Lumia.Imaging.Compositing Namespace