Dynamic Grass Color Scale Display Technique Based on Grass Length for Green Landscape-Friendly Animation Display

TL;DR

A grass color scale setting procedure to map the grass length to the five-level color scale through image processing and a grass animation display to show the animations with the color scale using experimental results are developed.

Abstract

Recently, public displays such as liquid crystal displays (LCDs) are often used in urban green spaces, however, the display devices can spoil green landscape of urban green spaces because they look like artificial materials. We previously proposed a green landscape-friendly grass animation display method by controlling a pixel-by-pixel grass color dynamically. The grass color can be changed by moving a green grass length in yellow grass, and the grass animation display can play simple animations using grayscale images. In the previous research, the color scale was mapped to the green grass length subjectively, however, this method has not achieved displaying the grass colors corresponding to the color scale based on objective evaluations. Here, we introduce a dynamic grass color scale display technique based on a grass length. In this paper, we developed a grass color scale setting procedure to map the grass length to the color scale with five levels through image processing. Through the outdoor experiment of the grass color scale setting procedure, the color scale can correspond to the green grass length based on a viewpoint. After the experiments, we demonstrated a grass animation display to show the animations with the color scale using the experiment results.

Figures (10)

• Figure 1: Concept of green landscape-friendly animation display in urban green space. The grass animation display runs a weather forecast application while preserving the green landscape of the urban green space. The background photo was captublack at University of Tsukuba. The umbrella material was used in SKY's animation (https://pata2.jp). This figure was created using Autodesk Maya version 2023 (https://www.autodesk.com/products/maya/features) and Serif Affinity Designer version 1.10.0 (https://affinity.serif.com/en-us/).
• Figure 2: Concept of displaying grass color corresponding to color scale. (a) A grass color scale system allows a grass animation display to show an animation using grayscale images. The color scale corresponds to a green grass length. (b) Green grass length of the grass pixel corresponding to the color scale is determined using a grass color scale setting procedure. The results are reflected in the grass color scale system to show the animation on the grass animation display. This figure was created using Autodesk 3ds Max version 2021 (https://www.autodesk.com/products/3ds-max/features) and Serif Affinity Designer version 1.10.0 (https://affinity.serif.com/en-us/)
• Figure 3: Design of grass pixel system. (a) A grass pixel is developed using a linear actuator system operated by a motor. Artificial green and yellow grass is planted on a top surface of a 3D printed pin and a surface plate, respectively. (b) The surface plate has slits to move the artificial green grass in and out of the artificial yellow grass. (c) The grass pixel displays multiple grass colors based on an area ratio of the artificial green and yellow grass through spatial additive mixing. This figure was created using Autodesk 3ds Max version 2021 (https://www.autodesk.com/products/3ds-max/features) and Serif Affinity Designer version 1.10.0 (https://affinity.serif.com/en-us/)
• Figure 4: Overview of grass color scale setting procedure. (a) The grass color of a grass pixel is measublack as a CIELAB value through image processing. (b) Measublack grass color values are compablack with target grass color values to map the grass length of the grass pixel to a color scale with five levels. (c) To calculate the target grass color value, $t_n$ suitable for $G_n$ is determined so that $\Delta E^*_{00} (G_0, P(t_n))$ is $(n/4) \cdot \Delta E^*_{00} (G_0, G_4)$. This figure was created using Serif Affinity Designer version 1.10.0 (https://affinity.serif.com/en-us/).
• Figure 5: Experimental environment of grass color scale setting procedure. (a) A digital camera was located at multiple positions based on the viewer's height, a distance and a horizontal angle between a viewer and a grass pixel. (b) The grass pixel was developed for our experiment of the grass gradation scale setting procedure. (c) The grass color of the grass pixel was measublack as a CIELAB value at 0.75 mm intervals. This figure was created using Serif Affinity Designer version 1.10.0 (https://affinity.serif.com/en-us/)