|
The new information contained in four additional spectral bands of high - resolution images from the satellite sensor WorldView - 2 should provide a visible improvement in the quality of analysis of large - scale phenomena occurring at the ground. Selected part of the image of Poznan was analyzed in order to verify these possibilities in relation to the urban environment. It includes riverside green area and a number of adjacent buildings. Attention has been focused on two components of object - oriented analysis - sharpening the image and its classification. In terms of pansharpening the aim was to obtain a clear picture of terrain objects in details, what should lead to the correct division of the image into homogenous segments and the subsequent fine classification. It was intended to ensure the possibility of separating small field objects within the set of classes. The task was carried out using various computer programs that enable the development and analysis of raster data (IDRISI Andes, ESRI ArcGIS 9.3, eCognition Developer 8) and some own computational modules. The main scientific objective of this study was to determine how much information from new spectral image layers after their pansharpening affects the quality of object - based classification of land cover in green and building areas of the city. As a basis for improving the quality of the classification was above mentioned ability of using additional data from new spectral bands of WorldView - 2 image. To assess the quality of the classification we used test that examines only the uncertain areas of t he picture, that is these which lie on differently classified types of land cover. The outcome of assessment confirmed the thesis of the positive albeit small impact of additional spectral channels on the result of object - based classification. But also pansharpening itself only slightly improves the quality of classified image
|