Question 14
A computer image is stored in a square grid; each small square is called 1 pixel. A video is stored as a sequence of such images.
For example, the picture above shows a video recording a 10×10 square moving in a 20×20 frame. Each image needs 20×20=400 pixels of storage. The video has 11 images, so it needs 400×11=4400 pixels of storage. However, each image differs from the preceding one in only a few details. To save storage, only the first image and the changes in each next image relative to the preceding one are stored. How many pixels are needed to store this video?
For example, the picture above shows a video recording a 10×10 square moving in a 20×20 frame. Each image needs 20×20=400 pixels of storage. The video has 11 images, so it needs 400×11=4400 pixels of storage. However, each image differs from the preceding one in only a few details. To save storage, only the first image and the changes in each next image relative to the preceding one are stored. How many pixels are needed to store this video?