Digital watermarking is the act of hiding a message related to a digital signal (i.e. an. image, song, video) within the signal itseclosely related to lf. It is a concept. steganography, in that they both hide a message inside a digital signal. However, what. separates them is their goal.
Wiktionary(0.00 / 0 votes)Rate this definition: 1  extrude(Verb) To push or thrust out. 2  extrude(Verb) To form or shape (a metal, plastic etc.) by forcing it through a die or an opening.
Contrails (/ËkÉntreÉªlz/ ; short for condensation trails) or vapor trails are line-shaped clouds sometimes produced by aircraft engine exhaust, typically at aircraft cruise altitudes several miles above the Earthâs surface. Contrails are composed primarily of water, in the form of ice crystals.The combination of water vapor in aircraft engine exhaust and the low ambient temperatures that often exists at these high altitudes allows the formation of the trails.he vapor then condenses into tiny water droplets which freeze if the temperature is low enough. These millions of tiny water droplets and/or ice crystals form the contrails. The time taken for the vapor to cool enough to condense accounts for the contrail forming some way behind the aircraft's engines.