I need to remove transparency from a PNG and replace White background

[zhongkon]

I need to remove transparency from a PNG and replace with white background. the commented out lines are things I have tried. it just keeps coming out transparent.

Imports SkiaSharp
Imports SkiaSharp.QrCode.Image
Using output = New FileStream(Application.StartupPath & "geo.png", FileMode.OpenOrCreate)
Dim Code = New QrCode("test qr code", New Vector2Slim(256, 256), SKEncodedImageFormat.Png)
Code.GenerateImage(output)
End Using

[zhongkon]

`Private Function GenerateQrCode(ByVal content As String, ByVal width As Integer, ByVal height As Integer) As Byte()
Using generator = New QRCodeGenerator()
Dim qr = generator.CreateQrCode(content, ECCLevel.L)
Dim info = New SKImageInfo(width, height)

        Using surface = SKSurface.Create(info)
            Dim canvas = surface.Canvas
            canvas.Clear(SKColors.White)

            Using qrCodeRenderer = New QRCodeRenderer()
                Dim area As SKRect = SKRect.Create(0, 0, info.Width, info.Height)
                qrCodeRenderer.Render(canvas, area, qr, SKColors.Black)
            End Using

            Using image = surface.Snapshot()

                Using data = image.Encode(SKEncodedImageFormat.Png, 100)

                    Using stream = File.OpenWrite(Application.StartupPath & "/geo.png")
                        data.SaveTo(stream)
                    End Using
                    Return data.ToArray()
                End Using
            End Using
        End Using
    End Using
End Function`