Determination of Planimetric Features by Interactive Image Processing

In aerial photography since roads and other man-made structures are small compared to natural features, their edges are usually indistinct from the background and are often undetected by automatic systems. A major problem in the development of such systems is the delineation of boundaries around areas containing features of interest. The computer is often unable to accomplish the detection process alone. Therefore, it is reasonable to combine the superior pattern recognition abilities of a human being with the computational power of a digital computer to form an interactive system. In this paper, an interactive feature extraction system is discussed. The hardware consists of a CDC-6400 sequential computer, a Goodyear STARAN associative array processor, a DEC PDP 11/50 minicomputer, image display, digitizing and recording devices. The feature extraction program for the interactive system consists of a series of routines which were installed in the system. The routines were written in FORTRAN and/or the STARAN assembly language according to the intended application in order to efficiently use the computers