Real-time ortho-rectification for remote-sensing images

Orthophoto imagery has been widely used in different fields, such as for preventing disasters and planning public facility construction. Orthophoto acquisition has become an urgent issue. However, the traditional ortho-rectification methods used to obtain orthophotos are time-consuming because these methods are almost all based on a personal computer (PC) system with a serial instruction system. To obtain an orthophoto in (near) real time, a field-programmable gate array (FPGA)-based ortho-rectification method has been proposed in this study. The architecture of the proposed method can be divided into three parts: (i) an input data module, (ii) a coordinate transformation module, and (iii) an interpolation module. Two aerial images are used to validate the speed and the rectified accuracy of the proposed method. Compared to the PC-based method, the results show that the proposed FPGA-based method is faster and can reach the correction accuracy requirement in practice.