Ramadan or Ramazan (Arabic: رَمَضَان, romanized: Ramaḍān also spelled Ramzan, Ramadhan, or Ramathan) is the ninth month of the Islamic calendar, observed by Muslims worldwide as a month of fasting (sawm), prayer, reflection and community. A commemoration of Muhammad's first revelation, the annual observance of Ramadan is regarded as one of the Five Pillars of Islam and lasts twenty-nine to thirty days, from one sighting of the crescent moon to the next. Fasting from sunrise to sunset is fard (obligatory) for all adult Muslims who are not acutely or chronically ill, travelling, elderly, pregnant, breastfeeding, diabetic, or menstruating. The predawn meal is referred to as suhur, and the nightly feast that breaks the fast is called iftar. Although fatwas have been issued declaring that Muslims who live in regions with a midnight sun or polar night should follow the timetable of Mecca, it is common practice to follow the timetable of the closest country in which night can be distinguished from day.
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.