Abstract
Usefulness of near infrared image acquired by commercial digital cameras is undisputable in remote sensing analysis for vegetation estimates and detection of faded black strokes on archeological wooden materials. It has not been so clear that what region of chromaticity space near infrared light signal would be reproduced in images of visible light. Is it possible for infrared images of foliage to be used to estimate vegetation activity of plant in captured images without using a high-cost and professional spectral radio-photometer? The main purpose of this research is to clarify the characteristics of infrared images by the digital camera and to utilize its special features for a lower-cost detection of vegetation activity from the infrared images. It was manifested that an artificial sunlight lamp shows several peaks in infrared spectral region and its reflection could be detected in the infrared images by digital cameras. The detection and estimation of foliage activity seems to be feasible to generate NDVI (Normal Difference Vegetation Index) distribution from near infrared image and visible red image acquired by the digital camera.
Results from the NDVI distribution map show high correlation with the NDVI derived by measured spectral reflectance of green foliage.
