The Kinect® camera is a section of the Kinect® motion-capture device that is responsible for picking up players and their movements during interactive gameplay. This camera is an infrared (IR) camera, meaning it picks up on IR light and separates entities by color. After the Kinect® camera takes in an image, it filters the objects to find human players, but the camera itself cannot pick up on fine details. Kinect® games use many different poses from an extensive digital library, and the camera looks for these to ensure the player performs the right pose. Running at an average of 30 frames per second (FPS), this camera is moderately fast and should not miss a player’s movement.
There are two main components in the Kinect® device that are responsible for picking up player movements, and one is the Kinect® camera. The second is an IR projector, which bounces IR light around a room, helping the camera pick up objects. When the camera sees an object, it classifies it based on location via color. For example, objects that are far away are gray, while closer objects are green or red.
The Kinect® camera is made to pay attention to people, so it runs the image through an image processing algorithm that determines what is a person and what is an animal or object that should be ignored. This keeps the camera from interpreting a dog’s movements as those of a player. While the camera knows what a person is and can recognize details such as height and hairstyle, it cannot capture fine details such as fingers, facial expressions and noses.
Around 200 poses are used with Kinect® games, and the Kinect® camera searches for those poses. For example, if the game tells the player to lift his or her right leg, then the camera will filter the player’s pose to see if it is correct. If the player is too far to the side and out of the camera’s view, it will take what it can see of the player and compare it to preloaded poses. This results in an educated guess of the player’s actual pose, which is normally accurate.
On average, the Kinect® camera will run at a speed of 30 FPS. While this is not the fastest camera in the world, it should be quick enough to capture a player’s every move and pose. At this speed, the camera can capture movements smoothly with a low error rate.