在 Windows Phone 应用程序中将动态 BitmapImage 转换为灰度 BitmapImage

我想将位图图像转换为灰度位图图像：这是我从方法中获得的，因此 - 宽度和高度对我来说是未知的。我尝试过研究 WritableBitmapEx 和静态扩展方法等选项，但它们对我没有帮助，因为我希望返回数据类型为 BitmapImage，然后需要将其添加到列表中。

在使用 C# 的 Windows Phone 应用程序中这可能吗？如果有人能对此有所启发，我将非常感激。谢谢。

该算法非常简单：

using System.Windows.Media.Imaging;
using System.IO;

private WriteableBitmap ConvertToGrayScale(BitmapImage source)
{
    WriteableBitmap wb = new WriteableBitmap(source);               // create the WritableBitmap using the source

    int[] grayPixels = new int[wb.PixelWidth * wb.PixelHeight];

    // lets use the average algo 
    for (int x = 0; x < wb.Pixels.Length; x++)
    {
        // get the pixel
        int pixel = wb.Pixels[x];

        // get the component
        int red = (pixel & 0x00FF0000) >> 16;
        int blue = (pixel & 0x0000FF00) >> 8;
        int green = (pixel & 0x000000FF);

        // get the average
        int average = (byte)((red + blue + green) / 3);

        // assign the gray values keep the alpha
        unchecked
        {
            grayPixels[x] = (int)((pixel & 0xFF000000) | average << 16 | average << 8 | average);
        }
    }



    // copy grayPixels back to Pixels
    Buffer.BlockCopy(grayPixels, 0, wb.Pixels, 0, (grayPixels.Length * 4));

    return wb;            
}

private BitmapImage ConvertWBtoBI(WriteableBitmap wb)
{
    BitmapImage bi;
    using (MemoryStream ms = new MemoryStream())
    {
        wb.SaveJpeg(ms, wb.PixelWidth, wb.PixelHeight, 0, 100);
        bi = new BitmapImage();
        bi.SetSource(ms);
    }
    return bi;
}

<Image x:Name="myImage" Source="/Assets/AlignmentGrid.png" Stretch="None" />

private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{       
    WriteableBitmap wb = ConvertToGrayScale((BitmapImage)this.myImage.Source);
    BitmapImage bi = ConvertWBtoBI(wb);


    myImage.Source = bi;       
}

实际代码：