Bowling is a sport or leisure activity in which a player rolls or throws a bowling ball towards a target. It is one of the major forms of throwing sports. In pin bowling variations, the target is usually to knock over pins at the end of a lane. A strike is when all the pins are knocked down on the first roll, whereas a spare is when all the pins are knocked over on the second shot. The maximum score is 300, which is achieved by getting 12 strikes in a row. Three consecutive strikes is a known as a "turkey". Further strings of strikes are referred to as the number with the word "bagger", such as "four-bagger" for four consecutive strikes. The term "hambone" has also been used to describe four consecutive strikes. In target variations, the aim is usually to get the ball as close to a mark as possible. The pin version of bowling is often played on a flat wooden or other synthetic surface (which can be oiled in different patterns for different techniques), while in target bowling, the surface may be grass, gravel or a synthetic surface.
Chroma key compositing, or chroma keying, is a special effects / post-production technique for compositing (layering) two images or video streams together based on color hues (chroma range). The technique has been used heavily in many fields to remove a background from the subject of a photo or video – particularly the newscasting, motion picture and videogame industries. A color range in the foreground footage is made transparent, allowing separately filmed background footage or a static image to be inserted into the scene. The chroma keying technique is commonly used in video production and post-production. This technique is also referred to as color keying, colour-separation overlay (CSO; primarily by the BBC), or by various terms for specific color-related variants such as green screen, and blue screen – chroma keying can be done with backgrounds of any color that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from most human skin colors. No part of the subject being filmed or photographed may duplicate the color used as the backing.