Spatial Registration of Multispectral and Multitemporal Digital Imagery Using Fast Fourier Transform Techniques

A system for spatial registration of digitized multispectral and multitemporal imagery is described. Multispectral imagery can be obtained from sources such as multilens cameras, multichannel optical-mechanical line scanners, or multiple vidicon systems which employ filters or other spectral separation techniques to sense selected portions of the spectrum. Spatial registration is required so that multidimensional analysis can be performed on contextually similar image elements from different wavelength bands and at different times. The general registration problem is discussed first; then the fast Fourier transform (FFT) technique for cross correlation of misregistered imagery to determine spatial distances is discussed in detail. A method of achieving translational, rotational, and scaling corrections between images is described. Results of correlation analysis of multispectral scanner imagery and digitized satellite photography is presented. Use of the system for registration of multispectral airborne line-scanner imagery and space photography is described. Application of the techniques to preprocessing of earth resources satellite imagery from systems such as the earth-resources technology satellite (ERTS) scanner and vidicon system is discussed in conclusion.