The screen ratio is the ratio of the screen width to the height, also known as the aspect ratio or aspect ratio. The standard screen ratios are usually 4:3 and 16:9. The aspect ratio of computer and data signals and ordinary TV signals is 4:3 or 1.33, and the aspect ratio of movies, DVDs and high-definition TVs is 16:9 or 1.78. When the aspect ratio of the input source image is different from the aspect ratio supported by the display device, the image will be distorted and lost. 16:9. When displaying images on a 4:3 screen, there are 3 methods: the first is deformation
(Windtracing) method, when it is full in the horizontal direction, stretch vertically until it fills the screen, so that the image looks thinner than the original image; the second method is the letterbox-A (Letterbox-A) method, and The 16:9 image is retained. It has no distortion, but there are black bars at the top and bottom of the screen. The third method is the -B (LetterboxB) method, which is a compromise between the first two methods. The second one is narrower and the aspect ratio of the image is 14:9. In order to meet the needs of home theaters, current home projectors usually have an aspect ratio of 16:9.