We proposed a novel index, NWI, to detect oak wilt, which has been wide-spreading around Japan Sea seaboard of the main island of Japan, from remotely sensed visible/near-infrared hyperspectral data. At first, we estimate differences in composition between oak wilt and healthy oak leaves based on pure spectral data collected by leaf level measurements. Subsequently, we characterized the spectrum by two distinctive features based on three narrow bands of green, red, and near infrared, i.e. i) NDGI as a normalized difference between green and red band and the numerical, ii) (NDVI+NDGI) as an approximation of the second-order central difference at red band. The NWI, defined by the product of -NDGI and (NDVI+NDGI), indicates positive value only in case of oak wilt leaves. The application of the NWI to remotely sensed airborne hyperspectral images provides a high accuracy extraction of oak wilt with an Az value from conditional ROC analysis of 0.95.
The 3D digital camera FinePix REAL 3D W1, which was designed to take a pair of stereo images for stereo viewing, was released by FUJIFILM Cooperation in August 2009. The aim of our study is to evaluate camera calibration methods for measuring dimensions of an object on a sub-meter scale by using a pair of stereo images acquired by the camera without any controls. Three camera calibration methods were evaluated by estimation errors of length of line segments measured without any controls. The experiment results indicate that the best calibration method for the camera would be the method that ordinary camera calibration is first executed for each imaging unit in order to estimate its image distortion model, and then alignment between two imaging units is estimated by using two sets of the exterior orientation parameters of both imaging units obtained in the ordinary camera calibration executed previously.
In this technical report, we propose a new clustering method based on histogram intersection. We prove the effectiveness the proposed method through experiments of land cover classification with multispectral image. Finally, we comment on the respects in which the proposed method is improved and on future prospects.
A GPS/IMU hybrid Inertial Navigation System is applied in wide range field to determine the position, attitude and heading. This paper introduces the various GPS/INS Systems and its Leading-edge Trend.