The sample data were taken in seven different landscape areas in Sydney, NSW, Australia. Field investigations were conducted between 31 January 2022 and 16 March 2022. Two different iPhones were used to capture soil images. The first one was an iPhone 11 Pro, and the second was an iPhone 6s. The bottom part of each soil sample was captured for the image. We kept a distance of 50 cm while taking images of the soil samples using iPhones. The resolution of the soil image was 2688 × 1242 pixels for the iPhone 11 Pro and 1080 × 1920 pixels for the iPhone 6s. Four image sets were taken from 38 soil samples according to the iPhone versions and direct and indirect sunlight conditions during the image capture. 629 images of 38 soil samples were taken and split into four datasets based on the image-capturing devices used (iPhone 6s and iPhone 11 Pro) and the lighting circumstances (direct and indirect sunlight).
The moisture meter device named ‘SDI-12 Sensor Reader’ was used to collect soil moisture samples to avoid complexity and improve the actual moisture value.
Light intensity is measured in Fc (lumens per square foot) or Lux (lumens per square meter). Even though multiple handheld devices are available in the market for the measurement of light intensity, an app named ‘Light Meter’ was operated using an iPhone’s back camera to document the light intensity levels during the image capture in this study. During the collection of Fc and Lux values using the ‘Light Meter’ app, we kept the iPhone’s camera vertical at 10 cm above the soil sample.