Active camouflage
（重定向自Optical camouflage）
![Many cephalopods such as this cuttlefish can change color rapidly for signalling or to match their backgrounds.](/Images/godic/202501/31/Cuttlefish_color3932.jpg")
![Illustrating the concept: active image capture and re-display creates an](/Images/godic/202501/31/Mediated-reality-easel3932.jpg")
![An invisibility cloak using active camouflage by Susumu Tachi. Left: The cloth seen without a special device. Right: The same cloth seen through the half-mirror projector part of the Retro-Reflective Projection Technology.](/Images/godic/202501/31/An_invisibility_cloak_using_optical_camouflage_by_Susumu_Tachi3932.jpg")
![Counterillumination camouflage of the firefly squid, Watasenia scintillans uses bioluminescence to match brightness and colour of the sea surface above.](/Images/godic/202501/31/Squid_Counterillumination3932.png")
Active camouflage or adaptive camouflage is camouflage that adapts, often rapidly, to the surroundings of an object such as an animal or military vehicle. In theory, active camouflage could provide perfect concealment from visual detection.
Active camouflage is used in several groups of animals, including reptiles on land, and cephalopod molluscs and flatfish in the sea. Animals achieve active camouflage both by color change and (among marine animals such as squid) by counterillumination, with the use of bioluminescence.