Reference Manual - 1.0.0
IDirectFBImageProvider   GetSurfaceDescription

Get a surface description that best matches the image contained in the file.

GetSurfaceDescription (
  IDirectFBImageProvider   * thiz,
  DFBSurfaceDescription   * ret_dsc
);

For opaque image formats the pixel format of the primary layer is used. For images with alpha channel an ARGB surface description is returned.