Picture.HasAlphaChannel
From Xojo Documentation
Read-Only Property (As Boolean )
True if the Picture has an alpha channel.
Notes
A Picture that is created with the constructor that omits the Depth parameter has an alpha channel and old pictures can be converted to this format with the following code:
Function ConvertToAlphaPicture(input As Picture) As Picture
If input.HasAlphaChannel Then Return input
Var result As New Picture(input.Width, input.Height)
result.Graphics.DrawPicture(input, 0, 0)
Return result
End Function
If input.HasAlphaChannel Then Return input
Var result As New Picture(input.Width, input.Height)
result.Graphics.DrawPicture(input, 0, 0)
Return result
End Function
For pictures using masks, HasAlphaChannel returns False.