In aerial images

a good description for window textures is of great significance for building extraction. In this paper

based on the result of vertical line extraction

the time-frequency analysis and the Radon transform are used to describe the directivity and periodicity of widow texture. First

in order to acquire periodic texture signals

gray-levels down the vertical lines are picked-up; and in order to enhance signal's robustness for noise and to catch the transversal orientation of texture

gray-levels along several quantitative directions are accumulated based on vertical lines

just like the well-known Radon transform. Second

the Fourier spectrum analysis is adopted to deduce the existence of window texture and its transversal orientation (namely the horizontal orientation of wall). With this understanding

the reliability of corresponding vertical line is ensured. However

its actual pixel positions are needed to be verified furthermore. To do so

the short-time Fourier spectrum of texture signal is computed sequentially

and the part with the same periodicity indicates the accurate location of vertical line. Lastly

the experimental results demonstrate that

reasonable analyses of window texture can be used to acquire reliable evidences for the presence of buildings and exact locations of their vertical lines

and to calculate local horizontal orientations of walls. The proposed algorithm provides a new favourable approach for the detection and acquisition of 3D information of buildings.