Rasterized PNG images are used in GDTF in several places - as a device thumbnail or as a MediaFileName in slots for gobo wheels and animation wheels. While the definition of a device thumbnail is quite simple (a png file to provide the rasterized picture with maximum resolution of picture 1024 x 1024), definition for a gobo slot image is more involved: Gobo images shall be in PNG format with an alpha channel. Indexed, Greyscale and Alpha, 8-bit RGB and Alpha, or 16-bit RGB and Alpha are acc