City region extraction processing method, city region extraction processing equipment, urban area extraction processing program and the program of the recording medium

摘要

PPROBLEM TO BE SOLVED: To extract an urban area more stably by paying attention to texture features in the urban area when the urban area is automatically extracted from a satellite photographic image, an aerial photographic image, etc. PSOLUTION: In an edge vector acquiring process 21, a two-dimensional edge vector having lateral and longitudinal difference values as vector components at each point of an input image 20 is imparted to each pixel and in a block acquiring process 23, a block of local areas including each pixel in the centers is generated. In an outer product sum calculating process 24, the absolute values of the vector outer products are calculated as to all combinations of two of all edge vectors in the block and summed up and in an urban area decision process 26, it is decided whether a representative point in the block is in the urban area according to the sum of vector outer products. PCOPYRIGHT: (C)2004,JPO