1. An information processing method comprising: making a video-image selection for cyclically acquiring at least two types of video images; making a mask determination for selecting, for each acquired video image, a mask pattern for masking the acquired video image by replacing some pixels composing the acquired video image with pixels of a single color such that said some pixels are spatially removed; and displaying on a display unit the video image after replacing said some pixels composing the video image with pixels of a single color based on the selected mask pattern, wherein, in the mask determination, when selecting a mask pattern for a certain video image, a mask pattern is selected that is different from a mask pattern used for the last video image, the mask pattern being different in the position of pixels not to be replaced with pixels of a single color.