Watermark Transition Duration
mark-transition-dur
Sets the duration of the image watermark transition in seconds. Applies to both the entrance and exit unless overridden by mark-transition-in-dur or mark-transition-out-dur.
mark-transition-dur accepts a float in seconds from 0 to 60. The default is 0.5 seconds. Use mark-transition-dur[N] for a specific watermark layer.