TY  - JOUR
T1  - A Comparison of the Performance of Pixel Based and Object Based Classifications over Images with Various Spatial Resolutions
AU - , Yan Gao AU - , Jean Francois Mas 
JO  - Online Journal of Earth Sciences
VL  - 2
IS  - 1
SP  - 27
EP  - 35
PY  - 2008
DA  - 2001/08/19
SN  - 1991-7708
DO  - ojesci.2008.27.35
UR  - https://makhillpublications.co/view-article.php?doi=ojesci.2008.27.35
KW  - Pixel-based image analysis
KW  -accuracy assessment
KW  -simulated images
AB  - In the last three decades, advances in computer technology, earth observation sensors and GIS science,  led  to the  development  of  “Object-based  Image  Analysis”  as  an  alternative  to  the  traditional pixel-based image analysis. Many studies have shown that traditional pixel-based image analysis is limited because it uses only spectral information of single pixels and this approach produces poor results especially with high spatial resolution satellite images. By contrast, object-based image analysis works on (homogeneous) objects which are produced by image segmentation and allows using more elements in the classification. As an object is a group of pixels, object characteristics such as mean value, standard deviation of spectral values, etc. can be calculated; besides shape and texture features of the objects are available and can be used to differentiate land cover classes with similar spectral information. These extra types of information give object-based image analysis the potential to produce land cover thematic maps with higher accuracies than those produced by traditional pixel-based method. In this study, we look at the performance of object-based image analysis in classifying satellite images with different spatial resolutions; comparing the classification results with those produced by the pixel-based method, we intend to find out how spatial resolution of satellite images influences the performance of object-based image analysis. The experiment showed that with relatively high spatial resolution images such as SPOT-5 and Landsat-7 ETM+, object-based image analysis obtained higher accuracy than that by the pixel-based one; while for coarse resolution images with 100 and 250 m spatial resolution, object based image analysis did not obtain higher accuracy. This study shows that the object-based image analysis has advantage over the pixel-based one, however the advantage was only found in the higher spatial resolution images.
ER  -