1. A method for detecting and removing a false contour, comprising: receiving an input video; determining, by a processor, that a pixel of the input video is included in a contour; calculating, by a processor, simplicity of the pixel; determining that the pixel is included in a false contour based on the simplicity and based on the pixel being included in the contour; and removing the false contour from the input video via smoothing with respect to the false contour, wherein the calculating the simplicity of the pixel comprises: determining whether each of at least one difference between adjacent pixels within a search window, including the pixel in a center thereof, is less than a predetermined difference; and calculating the simplicity of the pixel based on the at least one difference between the adjacent pixels when the at least one difference is less than the predetermined difference.