This paper introduces a display technique to show gradation animation using a shape-changing artificial grass system. Recently, liquid crystal displays and projectors have been used in a natural public facility, such as a park, but their artificial appearance can spoil the natural scenery. The proposed method is useful for developing a natural landscapefriendly display. We developed a grass pixel system to display the gradation. The grass pixel consists of yellow and green grass, and the length

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... of the green grass moves vertically. The grass pixel uses a pin-based shape-changing system using a stepper motor to control the grass length dynamically. We evaluated the grass pixel gradation using an image processing of HSV (Hue, Saturation, Value of Brightness) values. In the measurement, the pixel system moved the grass length from minimum to maximum, and we took images of the running grass pixel from several angles. As a result, we observed that the HSV values changed linearly with the movement of the length of the green grass. We also developed a 3 × 3 pixels grass display, which can demonstrate several gradation animations.