Question: Aliasing takes high spatial frequencies to low spatial frequencies. Explain why following effects occur:
• In old cowboy films that show wagons moving, the wheel often seems to be stationary or moving in the wrong direction (i.e. the wagon moves from left to right and the wheel seems to be turning anticlockwise).
• White shirts with thin dark pinstripes often generate a shimmering array of colors on television.
• In ray-traced pictures, soft shadows generated by area sources look blocky.