Development and Validation of a Colorimetric Method for Soil Classification by Comparing Color Systems in Images Captured by Mobile Devices.

• Grant number: 23/11524-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date until: September 01, 2023
• End date until: August 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Márcia Andreia Mesquita Silva da Veiga
• Grantee: Rafael Romano
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The soil color is one of the most straightforward and essential characteristics for obtaining information about a soil sample from a particular region. Coloring can provide insights into topography, vegetation, climate, and other properties. Generally, soil color is determined through visual comparison with the Munsell color chart, which classifies colors based on hue, value, and chroma. However, visually selecting soil color is subjective due to factors like incident light and the spectral response of the human eye. Considering these factors, this research project proposes using mobile devices, such as smartphones, as a precise and cost-effective alternative for soil color analysis. With the help of free applications, the RGB values obtained directly from images will be decoded and compared with the Munsell color system. Data obtained directly from apps and processed through Principal Component Analysis (PCA) will be compared to minimize errors arising from ambient lighting or smartphone sensor variations. The relationship between soil color and its most relevant physical and chemical properties, such as macro- and micronutrients, particle size distribution, and pH, will also be investigated. The developed methodology is expected to efficiently discriminate soil samples, particularly those with forensic purposes, to determine their potential association with a crime scene.