From Real Software Documentation
Controls the transparency of the white 'layer' of the picture.
It can take on either of the following values:
0 - Not transparent.
1 - White is transparent.
In version 2011r4, Real Studio introduced support for transparency via the alpha channel. If you need transparency, use the new constructor that takes advantage of this feature. For old pictures, you can add an alpha channel via the ModernizePicture function that is presented in the Notes section.
This example turns on transparency (for older Picture files).