using (var bmp = WicBitmapSource.Load(@"myJpegFile.jpg"))
{
    bmp.Save("myHeicFile.heic");
}

using (var bmp = WicBitmapSource.Load("MyImag.jpg"))
{
    bmp.ConvertTo(WicPixelFormat.GUID_WICPixelFormat32bppBGR);  // needed to be able to work with Direct2D
    var width = 200;
    var height = width * bmp.Height / bmp.Width;
    using (var memBmp = new WicBitmapSource(width, height, WicPixelFormat.GUID_WICPixelFormat32bppPRGBA))
    using (var rt = memBmp.CreateDeviceContext())
    using (var dbmp = rt.CreateBitmapFromWicBitmap(bmp.ComObject))
    using (var brush = rt.CreateSolidColorBrush(_D3DCOLORVALUE.Red))
    {
        rt.BeginDraw();
        rt.DrawBitmap(dbmp, destinationRectangle: new D2D_RECT_F(new D2D_SIZE_F(memBmp.Size)));
        rt.DrawEllipse(new D2D1_ELLIPSE(width / 2, height / 2, Math.Min(width, height) / 2), brush, 4);
        rt.EndDraw();
        memBmp.Save("ellipse.jpg");
    }
}

static void RotateAndGrayscale()
{
    using (var bmp = WicBitmapSource.Load("MyImage.jpg"))
    {
        bmp.Rotate(WICBitmapTransformOptions.WICBitmapTransformRotate90);
        bmp.ConvertTo(WicPixelFormat.GUID_WICPixelFormat32bppBGR); // needed to be able to work with Direct2D
        using (var newBmp = new WicBitmapSource(bmp.Width, bmp.Height, WicPixelFormat.GUID_WICPixelFormat32bppPRGBA))
        using (var rt = newBmp.CreateDeviceContext())
        using (var fx = rt.CreateEffect(Direct2DEffects.CLSID_D2D1Grayscale))
        using (var cb = rt.CreateBitmapFromWicBitmap(bmp.ComObject))
        {
            fx.SetInput(0, cb);
            rt.BeginDraw();
            rt.DrawImage(fx);
            rt.EndDraw();
            newBmp.Save("gray.jpg");
        }
    }
}

private static SoftwareBitmap GetSoftwareBitmap(string filePath)
{
    using var bmp = WicBitmapSource.Load(filePath);

    // note: software bitmap doesn't seem to support color contexts
    // so we must transform it ourselves, building one using pixels after color transformation
    // this is the moral equivalent to WinRT's BitmapDecoder.GetPixelDataAsync (which uses Wic underneath...)
    // https://learn.microsoft.com/en-us/uwp/api/windows.graphics.imaging.bitmapdecoder.getpixeldataasync
    var ctx = bmp.GetColorContexts();
    if (ctx.Count > 0)
    {
        using var transformed = GetTransformed(bmp);
        if (transformed != null)
        {
            // get pixels as an array of bytes
            var bytes = transformed.CopyPixels();

            // get WinRT SoftwareBitmap
            var softwareBitmap = new SoftwareBitmap(
                BitmapPixelFormat.Bgra8,
                bmp.Width,
                bmp.Height,
                BitmapAlphaMode.Premultiplied);
            softwareBitmap.CopyFromBuffer(bytes.AsBuffer());
            return softwareBitmap;
        }
    }

    // software bitmap doesn't support all formats
    // https://learn.microsoft.com/en-us/uwp/api/windows.graphics.imaging.bitmappixelformat
    // and SoftwareBitmapSource only support Bgra8...
    bmp.ConvertTo(WicPixelFormat.GUID_WICPixelFormat32bppPBGRA);

    // software bitmap doesn't support "raw" IWicBitmapSource, it wants an IWicBitmap
    using var clone = bmp.Clone();
    return clone.WithSoftwareBitmap(true, ptr => SoftwareBitmap.FromAbi(ptr));
}