Green Reference, A New Hyperspectral Image Referencing Technique
The Leafspec portable imaging device had provided a reliable low-cost hyperspectral image acquisition solution to a wide range of users. The Leafspec implemented a enclosed imaging environment and a build-in halogen light source, which eliminated the influence of ambient light. However, a uniform light source was hard to achieve due to dimension and power restrains. White Reference, in many cases refer to an image of a uniform white material such as a Teflon board. White Referencing is a widely used calibration technique in the effort of minimizing noises in an image, including ones that are induced by the light source. However, an abnormal spatial distribution was found remained in images collected by Leafspec even after performing White Referencing technique. In hypothesis, the huge spectral difference between Teflon board and leaves caused this issue. Following this assumption, this article proposed to use a uniform section of soybean leaf to create a Green Reference for calibrating hyperspectral images. In our experiment, 20 green reference samples were collected by imaging a 15 𝑚𝑚 × 15 𝑚𝑚 most uniform section from soybean leaf along a 100 𝑚𝑚 imaging window with a 5 𝑚𝑚 increment.
- Master of Science
- Agricultural and Biological Engineering
- West Lafayette