Converts SDL surface to TImageData structure.

function CreateImageFromSDLSurface(Surface: PSDL_Surface; 
                                   var ImageData: TImageData; 
                                   OverrideFormat: TImageFormat = ifUnknown): Boolean;

ImagingSDL (at line 76)

OverrideFormat can be used to convert output image to the specified format rather than use the format taken from SDL surface, ifUnknown means no conversion.